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llvm-mirror/lib/CodeGen/SelectionDAG/TargetLowering.cpp
Duncan Sands bbd03677ee Add a new codegen pass that normalizes dwarf exception handling 
code in preparation for code generation.  The main thing it does
is handle the case when eh.exception calls (and, in a future
patch, eh.selector calls) are far away from landing pads.  Right
now in practice you only find eh.exception calls close to landing
pads: either in a landing pad (the common case) or in a landing
pad successor, due to loop passes shifting them about.  However
future exception handling improvements will result in calls far
from landing pads:
(1) Inlining of rewinds.  Consider the following case:
In function @f:
...
  invoke @g to label %normal unwind label %unwinds
...
unwinds:
  %ex = call i8* @llvm.eh.exception()
...

In function @g:
...
  invoke @something to label %continue unwind label %handler
...
handler:
  %ex = call i8* @llvm.eh.exception()
... perform cleanups ...
  "rethrow exception"

Now inline @g into @f.  Currently this is turned into:
In function @f:
...
  invoke @something to label %continue unwind label %handler
...
handler:
  %ex = call i8* @llvm.eh.exception()
... perform cleanups ...
  invoke "rethrow exception" to label %normal unwind label %unwinds
unwinds:
  %ex = call i8* @llvm.eh.exception()
...

However we would like to simplify invoke of "rethrow exception" into
a branch to the %unwinds label.  Then %unwinds is no longer a landing
pad, and the eh.exception call there is then far away from any landing
pads.

(2) Using the unwind instruction for cleanups.
It would be nice to have codegen handle the following case:
  invoke @something to label %continue unwind label %run_cleanups
...
handler:
... perform cleanups ...
  unwind

This requires turning "unwind" into a library call, which
necessarily takes a pointer to the exception as an argument
(this patch also does this unwind lowering).  But that means
you are using eh.exception again far from a landing pad.

(3) Bugpoint simplifications.  When bugpoint is simplifying
exception handling code it often generates eh.exception calls
far from a landing pad, which then causes codegen to assert.
Bugpoint then latches on to this assertion and loses sight
of the original problem.

Note that it is currently rare for this pass to actually do
anything.  And in fact it normally shouldn't do anything at
all given the code coming out of llvm-gcc!  But it does fire
a few times in the testsuite.  As far as I can see this is
almost always due to the LoopStrengthReduce codegen pass
introducing pointless loop preheader blocks which are landing
pads and only contain a branch to another block.  This other
block contains an eh.exception call.  So probably by tweaking
LoopStrengthReduce a bit this can be avoided.

llvm-svn: 72276
2009-05-22 20:36:31 +00:00

2593 lines
103 KiB
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//===-- TargetLowering.cpp - Implement the TargetLowering class -----------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This implements the TargetLowering class.
//
//===----------------------------------------------------------------------===//
#include "llvm/Target/TargetAsmInfo.h"
#include "llvm/Target/TargetLowering.h"
#include "llvm/Target/TargetSubtarget.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetRegisterInfo.h"
#include "llvm/GlobalVariable.h"
#include "llvm/DerivedTypes.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Support/MathExtras.h"
using namespace llvm;
namespace llvm {
TLSModel::Model getTLSModel(const GlobalValue *GV, Reloc::Model reloc) {
bool isLocal = GV->hasLocalLinkage();
bool isDeclaration = GV->isDeclaration();
// FIXME: what should we do for protected and internal visibility?
// For variables, is internal different from hidden?
bool isHidden = GV->hasHiddenVisibility();
if (reloc == Reloc::PIC_) {
if (isLocal || isHidden)
return TLSModel::LocalDynamic;
else
return TLSModel::GeneralDynamic;
} else {
if (!isDeclaration || isHidden)
return TLSModel::LocalExec;
else
return TLSModel::InitialExec;
}
}
}
/// InitLibcallNames - Set default libcall names.
///
static void InitLibcallNames(const char **Names) {
Names[RTLIB::SHL_I16] = "__ashlhi3";
Names[RTLIB::SHL_I32] = "__ashlsi3";
Names[RTLIB::SHL_I64] = "__ashldi3";
Names[RTLIB::SHL_I128] = "__ashlti3";
Names[RTLIB::SRL_I16] = "__lshrhi3";
Names[RTLIB::SRL_I32] = "__lshrsi3";
Names[RTLIB::SRL_I64] = "__lshrdi3";
Names[RTLIB::SRL_I128] = "__lshrti3";
Names[RTLIB::SRA_I16] = "__ashrhi3";
Names[RTLIB::SRA_I32] = "__ashrsi3";
Names[RTLIB::SRA_I64] = "__ashrdi3";
Names[RTLIB::SRA_I128] = "__ashrti3";
Names[RTLIB::MUL_I16] = "__mulhi3";
Names[RTLIB::MUL_I32] = "__mulsi3";
Names[RTLIB::MUL_I64] = "__muldi3";
Names[RTLIB::MUL_I128] = "__multi3";
Names[RTLIB::SDIV_I16] = "__divhi3";
Names[RTLIB::SDIV_I32] = "__divsi3";
Names[RTLIB::SDIV_I64] = "__divdi3";
Names[RTLIB::SDIV_I128] = "__divti3";
Names[RTLIB::UDIV_I16] = "__udivhi3";
Names[RTLIB::UDIV_I32] = "__udivsi3";
Names[RTLIB::UDIV_I64] = "__udivdi3";
Names[RTLIB::UDIV_I128] = "__udivti3";
Names[RTLIB::SREM_I16] = "__modhi3";
Names[RTLIB::SREM_I32] = "__modsi3";
Names[RTLIB::SREM_I64] = "__moddi3";
Names[RTLIB::SREM_I128] = "__modti3";
Names[RTLIB::UREM_I16] = "__umodhi3";
Names[RTLIB::UREM_I32] = "__umodsi3";
Names[RTLIB::UREM_I64] = "__umoddi3";
Names[RTLIB::UREM_I128] = "__umodti3";
Names[RTLIB::NEG_I32] = "__negsi2";
Names[RTLIB::NEG_I64] = "__negdi2";
Names[RTLIB::ADD_F32] = "__addsf3";
Names[RTLIB::ADD_F64] = "__adddf3";
Names[RTLIB::ADD_F80] = "__addxf3";
Names[RTLIB::ADD_PPCF128] = "__gcc_qadd";
Names[RTLIB::SUB_F32] = "__subsf3";
Names[RTLIB::SUB_F64] = "__subdf3";
Names[RTLIB::SUB_F80] = "__subxf3";
Names[RTLIB::SUB_PPCF128] = "__gcc_qsub";
Names[RTLIB::MUL_F32] = "__mulsf3";
Names[RTLIB::MUL_F64] = "__muldf3";
Names[RTLIB::MUL_F80] = "__mulxf3";
Names[RTLIB::MUL_PPCF128] = "__gcc_qmul";
Names[RTLIB::DIV_F32] = "__divsf3";
Names[RTLIB::DIV_F64] = "__divdf3";
Names[RTLIB::DIV_F80] = "__divxf3";
Names[RTLIB::DIV_PPCF128] = "__gcc_qdiv";
Names[RTLIB::REM_F32] = "fmodf";
Names[RTLIB::REM_F64] = "fmod";
Names[RTLIB::REM_F80] = "fmodl";
Names[RTLIB::REM_PPCF128] = "fmodl";
Names[RTLIB::POWI_F32] = "__powisf2";
Names[RTLIB::POWI_F64] = "__powidf2";
Names[RTLIB::POWI_F80] = "__powixf2";
Names[RTLIB::POWI_PPCF128] = "__powitf2";
Names[RTLIB::SQRT_F32] = "sqrtf";
Names[RTLIB::SQRT_F64] = "sqrt";
Names[RTLIB::SQRT_F80] = "sqrtl";
Names[RTLIB::SQRT_PPCF128] = "sqrtl";
Names[RTLIB::LOG_F32] = "logf";
Names[RTLIB::LOG_F64] = "log";
Names[RTLIB::LOG_F80] = "logl";
Names[RTLIB::LOG_PPCF128] = "logl";
Names[RTLIB::LOG2_F32] = "log2f";
Names[RTLIB::LOG2_F64] = "log2";
Names[RTLIB::LOG2_F80] = "log2l";
Names[RTLIB::LOG2_PPCF128] = "log2l";
Names[RTLIB::LOG10_F32] = "log10f";
Names[RTLIB::LOG10_F64] = "log10";
Names[RTLIB::LOG10_F80] = "log10l";
Names[RTLIB::LOG10_PPCF128] = "log10l";
Names[RTLIB::EXP_F32] = "expf";
Names[RTLIB::EXP_F64] = "exp";
Names[RTLIB::EXP_F80] = "expl";
Names[RTLIB::EXP_PPCF128] = "expl";
Names[RTLIB::EXP2_F32] = "exp2f";
Names[RTLIB::EXP2_F64] = "exp2";
Names[RTLIB::EXP2_F80] = "exp2l";
Names[RTLIB::EXP2_PPCF128] = "exp2l";
Names[RTLIB::SIN_F32] = "sinf";
Names[RTLIB::SIN_F64] = "sin";
Names[RTLIB::SIN_F80] = "sinl";
Names[RTLIB::SIN_PPCF128] = "sinl";
Names[RTLIB::COS_F32] = "cosf";
Names[RTLIB::COS_F64] = "cos";
Names[RTLIB::COS_F80] = "cosl";
Names[RTLIB::COS_PPCF128] = "cosl";
Names[RTLIB::POW_F32] = "powf";
Names[RTLIB::POW_F64] = "pow";
Names[RTLIB::POW_F80] = "powl";
Names[RTLIB::POW_PPCF128] = "powl";
Names[RTLIB::CEIL_F32] = "ceilf";
Names[RTLIB::CEIL_F64] = "ceil";
Names[RTLIB::CEIL_F80] = "ceill";
Names[RTLIB::CEIL_PPCF128] = "ceill";
Names[RTLIB::TRUNC_F32] = "truncf";
Names[RTLIB::TRUNC_F64] = "trunc";
Names[RTLIB::TRUNC_F80] = "truncl";
Names[RTLIB::TRUNC_PPCF128] = "truncl";
Names[RTLIB::RINT_F32] = "rintf";
Names[RTLIB::RINT_F64] = "rint";
Names[RTLIB::RINT_F80] = "rintl";
Names[RTLIB::RINT_PPCF128] = "rintl";
Names[RTLIB::NEARBYINT_F32] = "nearbyintf";
Names[RTLIB::NEARBYINT_F64] = "nearbyint";
Names[RTLIB::NEARBYINT_F80] = "nearbyintl";
Names[RTLIB::NEARBYINT_PPCF128] = "nearbyintl";
Names[RTLIB::FLOOR_F32] = "floorf";
Names[RTLIB::FLOOR_F64] = "floor";
Names[RTLIB::FLOOR_F80] = "floorl";
Names[RTLIB::FLOOR_PPCF128] = "floorl";
Names[RTLIB::FPEXT_F32_F64] = "__extendsfdf2";
Names[RTLIB::FPROUND_F64_F32] = "__truncdfsf2";
Names[RTLIB::FPROUND_F80_F32] = "__truncxfsf2";
Names[RTLIB::FPROUND_PPCF128_F32] = "__trunctfsf2";
Names[RTLIB::FPROUND_F80_F64] = "__truncxfdf2";
Names[RTLIB::FPROUND_PPCF128_F64] = "__trunctfdf2";
Names[RTLIB::FPTOSINT_F32_I32] = "__fixsfsi";
Names[RTLIB::FPTOSINT_F32_I64] = "__fixsfdi";
Names[RTLIB::FPTOSINT_F32_I128] = "__fixsfti";
Names[RTLIB::FPTOSINT_F64_I32] = "__fixdfsi";
Names[RTLIB::FPTOSINT_F64_I64] = "__fixdfdi";
Names[RTLIB::FPTOSINT_F64_I128] = "__fixdfti";
Names[RTLIB::FPTOSINT_F80_I32] = "__fixxfsi";
Names[RTLIB::FPTOSINT_F80_I64] = "__fixxfdi";
Names[RTLIB::FPTOSINT_F80_I128] = "__fixxfti";
Names[RTLIB::FPTOSINT_PPCF128_I32] = "__fixtfsi";
Names[RTLIB::FPTOSINT_PPCF128_I64] = "__fixtfdi";
Names[RTLIB::FPTOSINT_PPCF128_I128] = "__fixtfti";
Names[RTLIB::FPTOUINT_F32_I32] = "__fixunssfsi";
Names[RTLIB::FPTOUINT_F32_I64] = "__fixunssfdi";
Names[RTLIB::FPTOUINT_F32_I128] = "__fixunssfti";
Names[RTLIB::FPTOUINT_F64_I32] = "__fixunsdfsi";
Names[RTLIB::FPTOUINT_F64_I64] = "__fixunsdfdi";
Names[RTLIB::FPTOUINT_F64_I128] = "__fixunsdfti";
Names[RTLIB::FPTOUINT_F80_I32] = "__fixunsxfsi";
Names[RTLIB::FPTOUINT_F80_I64] = "__fixunsxfdi";
Names[RTLIB::FPTOUINT_F80_I128] = "__fixunsxfti";
Names[RTLIB::FPTOUINT_PPCF128_I32] = "__fixunstfsi";
Names[RTLIB::FPTOUINT_PPCF128_I64] = "__fixunstfdi";
Names[RTLIB::FPTOUINT_PPCF128_I128] = "__fixunstfti";
Names[RTLIB::SINTTOFP_I32_F32] = "__floatsisf";
Names[RTLIB::SINTTOFP_I32_F64] = "__floatsidf";
Names[RTLIB::SINTTOFP_I32_F80] = "__floatsixf";
Names[RTLIB::SINTTOFP_I32_PPCF128] = "__floatsitf";
Names[RTLIB::SINTTOFP_I64_F32] = "__floatdisf";
Names[RTLIB::SINTTOFP_I64_F64] = "__floatdidf";
Names[RTLIB::SINTTOFP_I64_F80] = "__floatdixf";
Names[RTLIB::SINTTOFP_I64_PPCF128] = "__floatditf";
Names[RTLIB::SINTTOFP_I128_F32] = "__floattisf";
Names[RTLIB::SINTTOFP_I128_F64] = "__floattidf";
Names[RTLIB::SINTTOFP_I128_F80] = "__floattixf";
Names[RTLIB::SINTTOFP_I128_PPCF128] = "__floattitf";
Names[RTLIB::UINTTOFP_I32_F32] = "__floatunsisf";
Names[RTLIB::UINTTOFP_I32_F64] = "__floatunsidf";
Names[RTLIB::UINTTOFP_I32_F80] = "__floatunsixf";
Names[RTLIB::UINTTOFP_I32_PPCF128] = "__floatunsitf";
Names[RTLIB::UINTTOFP_I64_F32] = "__floatundisf";
Names[RTLIB::UINTTOFP_I64_F64] = "__floatundidf";
Names[RTLIB::UINTTOFP_I64_F80] = "__floatundixf";
Names[RTLIB::UINTTOFP_I64_PPCF128] = "__floatunditf";
Names[RTLIB::UINTTOFP_I128_F32] = "__floatuntisf";
Names[RTLIB::UINTTOFP_I128_F64] = "__floatuntidf";
Names[RTLIB::UINTTOFP_I128_F80] = "__floatuntixf";
Names[RTLIB::UINTTOFP_I128_PPCF128] = "__floatuntitf";
Names[RTLIB::OEQ_F32] = "__eqsf2";
Names[RTLIB::OEQ_F64] = "__eqdf2";
Names[RTLIB::UNE_F32] = "__nesf2";
Names[RTLIB::UNE_F64] = "__nedf2";
Names[RTLIB::OGE_F32] = "__gesf2";
Names[RTLIB::OGE_F64] = "__gedf2";
Names[RTLIB::OLT_F32] = "__ltsf2";
Names[RTLIB::OLT_F64] = "__ltdf2";
Names[RTLIB::OLE_F32] = "__lesf2";
Names[RTLIB::OLE_F64] = "__ledf2";
Names[RTLIB::OGT_F32] = "__gtsf2";
Names[RTLIB::OGT_F64] = "__gtdf2";
Names[RTLIB::UO_F32] = "__unordsf2";
Names[RTLIB::UO_F64] = "__unorddf2";
Names[RTLIB::O_F32] = "__unordsf2";
Names[RTLIB::O_F64] = "__unorddf2";
Names[RTLIB::UNWIND_RESUME] = "_Unwind_Resume";
}
/// getFPEXT - Return the FPEXT_*_* value for the given types, or
/// UNKNOWN_LIBCALL if there is none.
RTLIB::Libcall RTLIB::getFPEXT(MVT OpVT, MVT RetVT) {
if (OpVT == MVT::f32) {
if (RetVT == MVT::f64)
return FPEXT_F32_F64;
}
return UNKNOWN_LIBCALL;
}
/// getFPROUND - Return the FPROUND_*_* value for the given types, or
/// UNKNOWN_LIBCALL if there is none.
RTLIB::Libcall RTLIB::getFPROUND(MVT OpVT, MVT RetVT) {
if (RetVT == MVT::f32) {
if (OpVT == MVT::f64)
return FPROUND_F64_F32;
if (OpVT == MVT::f80)
return FPROUND_F80_F32;
if (OpVT == MVT::ppcf128)
return FPROUND_PPCF128_F32;
} else if (RetVT == MVT::f64) {
if (OpVT == MVT::f80)
return FPROUND_F80_F64;
if (OpVT == MVT::ppcf128)
return FPROUND_PPCF128_F64;
}
return UNKNOWN_LIBCALL;
}
/// getFPTOSINT - Return the FPTOSINT_*_* value for the given types, or
/// UNKNOWN_LIBCALL if there is none.
RTLIB::Libcall RTLIB::getFPTOSINT(MVT OpVT, MVT RetVT) {
if (OpVT == MVT::f32) {
if (RetVT == MVT::i32)
return FPTOSINT_F32_I32;
if (RetVT == MVT::i64)
return FPTOSINT_F32_I64;
if (RetVT == MVT::i128)
return FPTOSINT_F32_I128;
} else if (OpVT == MVT::f64) {
if (RetVT == MVT::i32)
return FPTOSINT_F64_I32;
if (RetVT == MVT::i64)
return FPTOSINT_F64_I64;
if (RetVT == MVT::i128)
return FPTOSINT_F64_I128;
} else if (OpVT == MVT::f80) {
if (RetVT == MVT::i32)
return FPTOSINT_F80_I32;
if (RetVT == MVT::i64)
return FPTOSINT_F80_I64;
if (RetVT == MVT::i128)
return FPTOSINT_F80_I128;
} else if (OpVT == MVT::ppcf128) {
if (RetVT == MVT::i32)
return FPTOSINT_PPCF128_I32;
if (RetVT == MVT::i64)
return FPTOSINT_PPCF128_I64;
if (RetVT == MVT::i128)
return FPTOSINT_PPCF128_I128;
}
return UNKNOWN_LIBCALL;
}
/// getFPTOUINT - Return the FPTOUINT_*_* value for the given types, or
/// UNKNOWN_LIBCALL if there is none.
RTLIB::Libcall RTLIB::getFPTOUINT(MVT OpVT, MVT RetVT) {
if (OpVT == MVT::f32) {
if (RetVT == MVT::i32)
return FPTOUINT_F32_I32;
if (RetVT == MVT::i64)
return FPTOUINT_F32_I64;
if (RetVT == MVT::i128)
return FPTOUINT_F32_I128;
} else if (OpVT == MVT::f64) {
if (RetVT == MVT::i32)
return FPTOUINT_F64_I32;
if (RetVT == MVT::i64)
return FPTOUINT_F64_I64;
if (RetVT == MVT::i128)
return FPTOUINT_F64_I128;
} else if (OpVT == MVT::f80) {
if (RetVT == MVT::i32)
return FPTOUINT_F80_I32;
if (RetVT == MVT::i64)
return FPTOUINT_F80_I64;
if (RetVT == MVT::i128)
return FPTOUINT_F80_I128;
} else if (OpVT == MVT::ppcf128) {
if (RetVT == MVT::i32)
return FPTOUINT_PPCF128_I32;
if (RetVT == MVT::i64)
return FPTOUINT_PPCF128_I64;
if (RetVT == MVT::i128)
return FPTOUINT_PPCF128_I128;
}
return UNKNOWN_LIBCALL;
}
/// getSINTTOFP - Return the SINTTOFP_*_* value for the given types, or
/// UNKNOWN_LIBCALL if there is none.
RTLIB::Libcall RTLIB::getSINTTOFP(MVT OpVT, MVT RetVT) {
if (OpVT == MVT::i32) {
if (RetVT == MVT::f32)
return SINTTOFP_I32_F32;
else if (RetVT == MVT::f64)
return SINTTOFP_I32_F64;
else if (RetVT == MVT::f80)
return SINTTOFP_I32_F80;
else if (RetVT == MVT::ppcf128)
return SINTTOFP_I32_PPCF128;
} else if (OpVT == MVT::i64) {
if (RetVT == MVT::f32)
return SINTTOFP_I64_F32;
else if (RetVT == MVT::f64)
return SINTTOFP_I64_F64;
else if (RetVT == MVT::f80)
return SINTTOFP_I64_F80;
else if (RetVT == MVT::ppcf128)
return SINTTOFP_I64_PPCF128;
} else if (OpVT == MVT::i128) {
if (RetVT == MVT::f32)
return SINTTOFP_I128_F32;
else if (RetVT == MVT::f64)
return SINTTOFP_I128_F64;
else if (RetVT == MVT::f80)
return SINTTOFP_I128_F80;
else if (RetVT == MVT::ppcf128)
return SINTTOFP_I128_PPCF128;
}
return UNKNOWN_LIBCALL;
}
/// getUINTTOFP - Return the UINTTOFP_*_* value for the given types, or
/// UNKNOWN_LIBCALL if there is none.
RTLIB::Libcall RTLIB::getUINTTOFP(MVT OpVT, MVT RetVT) {
if (OpVT == MVT::i32) {
if (RetVT == MVT::f32)
return UINTTOFP_I32_F32;
else if (RetVT == MVT::f64)
return UINTTOFP_I32_F64;
else if (RetVT == MVT::f80)
return UINTTOFP_I32_F80;
else if (RetVT == MVT::ppcf128)
return UINTTOFP_I32_PPCF128;
} else if (OpVT == MVT::i64) {
if (RetVT == MVT::f32)
return UINTTOFP_I64_F32;
else if (RetVT == MVT::f64)
return UINTTOFP_I64_F64;
else if (RetVT == MVT::f80)
return UINTTOFP_I64_F80;
else if (RetVT == MVT::ppcf128)
return UINTTOFP_I64_PPCF128;
} else if (OpVT == MVT::i128) {
if (RetVT == MVT::f32)
return UINTTOFP_I128_F32;
else if (RetVT == MVT::f64)
return UINTTOFP_I128_F64;
else if (RetVT == MVT::f80)
return UINTTOFP_I128_F80;
else if (RetVT == MVT::ppcf128)
return UINTTOFP_I128_PPCF128;
}
return UNKNOWN_LIBCALL;
}
/// InitCmpLibcallCCs - Set default comparison libcall CC.
///
static void InitCmpLibcallCCs(ISD::CondCode *CCs) {
memset(CCs, ISD::SETCC_INVALID, sizeof(ISD::CondCode)*RTLIB::UNKNOWN_LIBCALL);
CCs[RTLIB::OEQ_F32] = ISD::SETEQ;
CCs[RTLIB::OEQ_F64] = ISD::SETEQ;
CCs[RTLIB::UNE_F32] = ISD::SETNE;
CCs[RTLIB::UNE_F64] = ISD::SETNE;
CCs[RTLIB::OGE_F32] = ISD::SETGE;
CCs[RTLIB::OGE_F64] = ISD::SETGE;
CCs[RTLIB::OLT_F32] = ISD::SETLT;
CCs[RTLIB::OLT_F64] = ISD::SETLT;
CCs[RTLIB::OLE_F32] = ISD::SETLE;
CCs[RTLIB::OLE_F64] = ISD::SETLE;
CCs[RTLIB::OGT_F32] = ISD::SETGT;
CCs[RTLIB::OGT_F64] = ISD::SETGT;
CCs[RTLIB::UO_F32] = ISD::SETNE;
CCs[RTLIB::UO_F64] = ISD::SETNE;
CCs[RTLIB::O_F32] = ISD::SETEQ;
CCs[RTLIB::O_F64] = ISD::SETEQ;
}
TargetLowering::TargetLowering(TargetMachine &tm)
: TM(tm), TD(TM.getTargetData()) {
// All operations default to being supported.
memset(OpActions, 0, sizeof(OpActions));
memset(LoadExtActions, 0, sizeof(LoadExtActions));
memset(TruncStoreActions, 0, sizeof(TruncStoreActions));
memset(IndexedModeActions, 0, sizeof(IndexedModeActions));
memset(ConvertActions, 0, sizeof(ConvertActions));
memset(CondCodeActions, 0, sizeof(CondCodeActions));
// Set default actions for various operations.
for (unsigned VT = 0; VT != (unsigned)MVT::LAST_VALUETYPE; ++VT) {
// Default all indexed load / store to expand.
for (unsigned IM = (unsigned)ISD::PRE_INC;
IM != (unsigned)ISD::LAST_INDEXED_MODE; ++IM) {
setIndexedLoadAction(IM, (MVT::SimpleValueType)VT, Expand);
setIndexedStoreAction(IM, (MVT::SimpleValueType)VT, Expand);
}
// These operations default to expand.
setOperationAction(ISD::FGETSIGN, (MVT::SimpleValueType)VT, Expand);
setOperationAction(ISD::CONCAT_VECTORS, (MVT::SimpleValueType)VT, Expand);
}
// Most targets ignore the @llvm.prefetch intrinsic.
setOperationAction(ISD::PREFETCH, MVT::Other, Expand);
// ConstantFP nodes default to expand. Targets can either change this to
// Legal, in which case all fp constants are legal, or use addLegalFPImmediate
// to optimize expansions for certain constants.
setOperationAction(ISD::ConstantFP, MVT::f32, Expand);
setOperationAction(ISD::ConstantFP, MVT::f64, Expand);
setOperationAction(ISD::ConstantFP, MVT::f80, Expand);
// These library functions default to expand.
setOperationAction(ISD::FLOG , MVT::f64, Expand);
setOperationAction(ISD::FLOG2, MVT::f64, Expand);
setOperationAction(ISD::FLOG10,MVT::f64, Expand);
setOperationAction(ISD::FEXP , MVT::f64, Expand);
setOperationAction(ISD::FEXP2, MVT::f64, Expand);
setOperationAction(ISD::FLOG , MVT::f32, Expand);
setOperationAction(ISD::FLOG2, MVT::f32, Expand);
setOperationAction(ISD::FLOG10,MVT::f32, Expand);
setOperationAction(ISD::FEXP , MVT::f32, Expand);
setOperationAction(ISD::FEXP2, MVT::f32, Expand);
// Default ISD::TRAP to expand (which turns it into abort).
setOperationAction(ISD::TRAP, MVT::Other, Expand);
IsLittleEndian = TD->isLittleEndian();
UsesGlobalOffsetTable = false;
ShiftAmountTy = PointerTy = getValueType(TD->getIntPtrType());
ShiftAmtHandling = Undefined;
memset(RegClassForVT, 0,MVT::LAST_VALUETYPE*sizeof(TargetRegisterClass*));
memset(TargetDAGCombineArray, 0, array_lengthof(TargetDAGCombineArray));
maxStoresPerMemset = maxStoresPerMemcpy = maxStoresPerMemmove = 8;
allowUnalignedMemoryAccesses = false;
benefitFromCodePlacementOpt = false;
UseUnderscoreSetJmp = false;
UseUnderscoreLongJmp = false;
SelectIsExpensive = false;
IntDivIsCheap = false;
Pow2DivIsCheap = false;
StackPointerRegisterToSaveRestore = 0;
ExceptionPointerRegister = 0;
ExceptionSelectorRegister = 0;
BooleanContents = UndefinedBooleanContent;
SchedPreferenceInfo = SchedulingForLatency;
JumpBufSize = 0;
JumpBufAlignment = 0;
IfCvtBlockSizeLimit = 2;
IfCvtDupBlockSizeLimit = 0;
PrefLoopAlignment = 0;
InitLibcallNames(LibcallRoutineNames);
InitCmpLibcallCCs(CmpLibcallCCs);
// Tell Legalize whether the assembler supports DEBUG_LOC.
const TargetAsmInfo *TASM = TM.getTargetAsmInfo();
if (!TASM || !TASM->hasDotLocAndDotFile())
setOperationAction(ISD::DEBUG_LOC, MVT::Other, Expand);
}
TargetLowering::~TargetLowering() {}
/// computeRegisterProperties - Once all of the register classes are added,
/// this allows us to compute derived properties we expose.
void TargetLowering::computeRegisterProperties() {
assert(MVT::LAST_VALUETYPE <= 32 &&
"Too many value types for ValueTypeActions to hold!");
// Everything defaults to needing one register.
for (unsigned i = 0; i != MVT::LAST_VALUETYPE; ++i) {
NumRegistersForVT[i] = 1;
RegisterTypeForVT[i] = TransformToType[i] = (MVT::SimpleValueType)i;
}
// ...except isVoid, which doesn't need any registers.
NumRegistersForVT[MVT::isVoid] = 0;
// Find the largest integer register class.
unsigned LargestIntReg = MVT::LAST_INTEGER_VALUETYPE;
for (; RegClassForVT[LargestIntReg] == 0; --LargestIntReg)
assert(LargestIntReg != MVT::i1 && "No integer registers defined!");
// Every integer value type larger than this largest register takes twice as
// many registers to represent as the previous ValueType.
for (unsigned ExpandedReg = LargestIntReg + 1; ; ++ExpandedReg) {
MVT EVT = (MVT::SimpleValueType)ExpandedReg;
if (!EVT.isInteger())
break;
NumRegistersForVT[ExpandedReg] = 2*NumRegistersForVT[ExpandedReg-1];
RegisterTypeForVT[ExpandedReg] = (MVT::SimpleValueType)LargestIntReg;
TransformToType[ExpandedReg] = (MVT::SimpleValueType)(ExpandedReg - 1);
ValueTypeActions.setTypeAction(EVT, Expand);
}
// Inspect all of the ValueType's smaller than the largest integer
// register to see which ones need promotion.
unsigned LegalIntReg = LargestIntReg;
for (unsigned IntReg = LargestIntReg - 1;
IntReg >= (unsigned)MVT::i1; --IntReg) {
MVT IVT = (MVT::SimpleValueType)IntReg;
if (isTypeLegal(IVT)) {
LegalIntReg = IntReg;
} else {
RegisterTypeForVT[IntReg] = TransformToType[IntReg] =
(MVT::SimpleValueType)LegalIntReg;
ValueTypeActions.setTypeAction(IVT, Promote);
}
}
// ppcf128 type is really two f64's.
if (!isTypeLegal(MVT::ppcf128)) {
NumRegistersForVT[MVT::ppcf128] = 2*NumRegistersForVT[MVT::f64];
RegisterTypeForVT[MVT::ppcf128] = MVT::f64;
TransformToType[MVT::ppcf128] = MVT::f64;
ValueTypeActions.setTypeAction(MVT::ppcf128, Expand);
}
// Decide how to handle f64. If the target does not have native f64 support,
// expand it to i64 and we will be generating soft float library calls.
if (!isTypeLegal(MVT::f64)) {
NumRegistersForVT[MVT::f64] = NumRegistersForVT[MVT::i64];
RegisterTypeForVT[MVT::f64] = RegisterTypeForVT[MVT::i64];
TransformToType[MVT::f64] = MVT::i64;
ValueTypeActions.setTypeAction(MVT::f64, Expand);
}
// Decide how to handle f32. If the target does not have native support for
// f32, promote it to f64 if it is legal. Otherwise, expand it to i32.
if (!isTypeLegal(MVT::f32)) {
if (isTypeLegal(MVT::f64)) {
NumRegistersForVT[MVT::f32] = NumRegistersForVT[MVT::f64];
RegisterTypeForVT[MVT::f32] = RegisterTypeForVT[MVT::f64];
TransformToType[MVT::f32] = MVT::f64;
ValueTypeActions.setTypeAction(MVT::f32, Promote);
} else {
NumRegistersForVT[MVT::f32] = NumRegistersForVT[MVT::i32];
RegisterTypeForVT[MVT::f32] = RegisterTypeForVT[MVT::i32];
TransformToType[MVT::f32] = MVT::i32;
ValueTypeActions.setTypeAction(MVT::f32, Expand);
}
}
// Loop over all of the vector value types to see which need transformations.
for (unsigned i = MVT::FIRST_VECTOR_VALUETYPE;
i <= (unsigned)MVT::LAST_VECTOR_VALUETYPE; ++i) {
MVT VT = (MVT::SimpleValueType)i;
if (!isTypeLegal(VT)) {
MVT IntermediateVT, RegisterVT;
unsigned NumIntermediates;
NumRegistersForVT[i] =
getVectorTypeBreakdown(VT,
IntermediateVT, NumIntermediates,
RegisterVT);
RegisterTypeForVT[i] = RegisterVT;
// Determine if there is a legal wider type.
bool IsLegalWiderType = false;
MVT EltVT = VT.getVectorElementType();
unsigned NElts = VT.getVectorNumElements();
for (unsigned nVT = i+1; nVT <= MVT::LAST_VECTOR_VALUETYPE; ++nVT) {
MVT SVT = (MVT::SimpleValueType)nVT;
if (isTypeLegal(SVT) && SVT.getVectorElementType() == EltVT &&
SVT.getVectorNumElements() > NElts) {
TransformToType[i] = SVT;
ValueTypeActions.setTypeAction(VT, Promote);
IsLegalWiderType = true;
break;
}
}
if (!IsLegalWiderType) {
MVT NVT = VT.getPow2VectorType();
if (NVT == VT) {
// Type is already a power of 2. The default action is to split.
TransformToType[i] = MVT::Other;
ValueTypeActions.setTypeAction(VT, Expand);
} else {
TransformToType[i] = NVT;
ValueTypeActions.setTypeAction(VT, Promote);
}
}
}
}
}
const char *TargetLowering::getTargetNodeName(unsigned Opcode) const {
return NULL;
}
MVT TargetLowering::getSetCCResultType(MVT VT) const {
return getValueType(TD->getIntPtrType());
}
/// getVectorTypeBreakdown - Vector types are broken down into some number of
/// legal first class types. For example, MVT::v8f32 maps to 2 MVT::v4f32
/// with Altivec or SSE1, or 8 promoted MVT::f64 values with the X86 FP stack.
/// Similarly, MVT::v2i64 turns into 4 MVT::i32 values with both PPC and X86.
///
/// This method returns the number of registers needed, and the VT for each
/// register. It also returns the VT and quantity of the intermediate values
/// before they are promoted/expanded.
///
unsigned TargetLowering::getVectorTypeBreakdown(MVT VT,
MVT &IntermediateVT,
unsigned &NumIntermediates,
MVT &RegisterVT) const {
// Figure out the right, legal destination reg to copy into.
unsigned NumElts = VT.getVectorNumElements();
MVT EltTy = VT.getVectorElementType();
unsigned NumVectorRegs = 1;
// FIXME: We don't support non-power-of-2-sized vectors for now. Ideally we
// could break down into LHS/RHS like LegalizeDAG does.
if (!isPowerOf2_32(NumElts)) {
NumVectorRegs = NumElts;
NumElts = 1;
}
// Divide the input until we get to a supported size. This will always
// end with a scalar if the target doesn't support vectors.
while (NumElts > 1 && !isTypeLegal(MVT::getVectorVT(EltTy, NumElts))) {
NumElts >>= 1;
NumVectorRegs <<= 1;
}
NumIntermediates = NumVectorRegs;
MVT NewVT = MVT::getVectorVT(EltTy, NumElts);
if (!isTypeLegal(NewVT))
NewVT = EltTy;
IntermediateVT = NewVT;
MVT DestVT = getRegisterType(NewVT);
RegisterVT = DestVT;
if (DestVT.bitsLT(NewVT)) {
// Value is expanded, e.g. i64 -> i16.
return NumVectorRegs*(NewVT.getSizeInBits()/DestVT.getSizeInBits());
} else {
// Otherwise, promotion or legal types use the same number of registers as
// the vector decimated to the appropriate level.
return NumVectorRegs;
}
return 1;
}
/// getWidenVectorType: given a vector type, returns the type to widen to
/// (e.g., v7i8 to v8i8). If the vector type is legal, it returns itself.
/// If there is no vector type that we want to widen to, returns MVT::Other
/// When and where to widen is target dependent based on the cost of
/// scalarizing vs using the wider vector type.
MVT TargetLowering::getWidenVectorType(MVT VT) const {
assert(VT.isVector());
if (isTypeLegal(VT))
return VT;
// Default is not to widen until moved to LegalizeTypes
return MVT::Other;
}
/// getByValTypeAlignment - Return the desired alignment for ByVal aggregate
/// function arguments in the caller parameter area. This is the actual
/// alignment, not its logarithm.
unsigned TargetLowering::getByValTypeAlignment(const Type *Ty) const {
return TD->getCallFrameTypeAlignment(Ty);
}
SDValue TargetLowering::getPICJumpTableRelocBase(SDValue Table,
SelectionDAG &DAG) const {
if (usesGlobalOffsetTable())
return DAG.getGLOBAL_OFFSET_TABLE(getPointerTy());
return Table;
}
bool
TargetLowering::isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const {
// Assume that everything is safe in static mode.
if (getTargetMachine().getRelocationModel() == Reloc::Static)
return true;
// In dynamic-no-pic mode, assume that known defined values are safe.
if (getTargetMachine().getRelocationModel() == Reloc::DynamicNoPIC &&
GA &&
!GA->getGlobal()->isDeclaration() &&
!GA->getGlobal()->isWeakForLinker())
return true;
// Otherwise assume nothing is safe.
return false;
}
//===----------------------------------------------------------------------===//
// Optimization Methods
//===----------------------------------------------------------------------===//
/// ShrinkDemandedConstant - Check to see if the specified operand of the
/// specified instruction is a constant integer. If so, check to see if there
/// are any bits set in the constant that are not demanded. If so, shrink the
/// constant and return true.
bool TargetLowering::TargetLoweringOpt::ShrinkDemandedConstant(SDValue Op,
const APInt &Demanded) {
DebugLoc dl = Op.getDebugLoc();
// FIXME: ISD::SELECT, ISD::SELECT_CC
switch (Op.getOpcode()) {
default: break;
case ISD::XOR:
case ISD::AND:
case ISD::OR: {
ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op.getOperand(1));
if (!C) return false;
if (Op.getOpcode() == ISD::XOR &&
(C->getAPIntValue() | (~Demanded)).isAllOnesValue())
return false;
// if we can expand it to have all bits set, do it
if (C->getAPIntValue().intersects(~Demanded)) {
MVT VT = Op.getValueType();
SDValue New = DAG.getNode(Op.getOpcode(), dl, VT, Op.getOperand(0),
DAG.getConstant(Demanded &
C->getAPIntValue(),
VT));
return CombineTo(Op, New);
}
break;
}
}
return false;
}
/// ShrinkDemandedOp - Convert x+y to (VT)((SmallVT)x+(SmallVT)y) if the
/// casts are free. This uses isZExtFree and ZERO_EXTEND for the widening
/// cast, but it could be generalized for targets with other types of
/// implicit widening casts.
bool
TargetLowering::TargetLoweringOpt::ShrinkDemandedOp(SDValue Op,
unsigned BitWidth,
const APInt &Demanded,
DebugLoc dl) {
assert(Op.getNumOperands() == 2 &&
"ShrinkDemandedOp only supports binary operators!");
assert(Op.getNode()->getNumValues() == 1 &&
"ShrinkDemandedOp only supports nodes with one result!");
// Don't do this if the node has another user, which may require the
// full value.
if (!Op.getNode()->hasOneUse())
return false;
// Search for the smallest integer type with free casts to and from
// Op's type. For expedience, just check power-of-2 integer types.
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
unsigned SmallVTBits = BitWidth - Demanded.countLeadingZeros();
if (!isPowerOf2_32(SmallVTBits))
SmallVTBits = NextPowerOf2(SmallVTBits);
for (; SmallVTBits < BitWidth; SmallVTBits = NextPowerOf2(SmallVTBits)) {
MVT SmallVT = MVT::getIntegerVT(SmallVTBits);
if (TLI.isTruncateFree(Op.getValueType(), SmallVT) &&
TLI.isZExtFree(SmallVT, Op.getValueType())) {
// We found a type with free casts.
SDValue X = DAG.getNode(Op.getOpcode(), dl, SmallVT,
DAG.getNode(ISD::TRUNCATE, dl, SmallVT,
Op.getNode()->getOperand(0)),
DAG.getNode(ISD::TRUNCATE, dl, SmallVT,
Op.getNode()->getOperand(1)));
SDValue Z = DAG.getNode(ISD::ZERO_EXTEND, dl, Op.getValueType(), X);
return CombineTo(Op, Z);
}
}
return false;
}
/// SimplifyDemandedBits - Look at Op. At this point, we know that only the
/// DemandedMask bits of the result of Op are ever used downstream. If we can
/// use this information to simplify Op, create a new simplified DAG node and
/// return true, returning the original and new nodes in Old and New. Otherwise,
/// analyze the expression and return a mask of KnownOne and KnownZero bits for
/// the expression (used to simplify the caller). The KnownZero/One bits may
/// only be accurate for those bits in the DemandedMask.
bool TargetLowering::SimplifyDemandedBits(SDValue Op,
const APInt &DemandedMask,
APInt &KnownZero,
APInt &KnownOne,
TargetLoweringOpt &TLO,
unsigned Depth) const {
unsigned BitWidth = DemandedMask.getBitWidth();
assert(Op.getValueSizeInBits() == BitWidth &&
"Mask size mismatches value type size!");
APInt NewMask = DemandedMask;
DebugLoc dl = Op.getDebugLoc();
// Don't know anything.
KnownZero = KnownOne = APInt(BitWidth, 0);
// Other users may use these bits.
if (!Op.getNode()->hasOneUse()) {
if (Depth != 0) {
// If not at the root, Just compute the KnownZero/KnownOne bits to
// simplify things downstream.
TLO.DAG.ComputeMaskedBits(Op, DemandedMask, KnownZero, KnownOne, Depth);
return false;
}
// If this is the root being simplified, allow it to have multiple uses,
// just set the NewMask to all bits.
NewMask = APInt::getAllOnesValue(BitWidth);
} else if (DemandedMask == 0) {
// Not demanding any bits from Op.
if (Op.getOpcode() != ISD::UNDEF)
return TLO.CombineTo(Op, TLO.DAG.getUNDEF(Op.getValueType()));
return false;
} else if (Depth == 6) { // Limit search depth.
return false;
}
APInt KnownZero2, KnownOne2, KnownZeroOut, KnownOneOut;
switch (Op.getOpcode()) {
case ISD::Constant:
// We know all of the bits for a constant!
KnownOne = cast<ConstantSDNode>(Op)->getAPIntValue() & NewMask;
KnownZero = ~KnownOne & NewMask;
return false; // Don't fall through, will infinitely loop.
case ISD::AND:
// If the RHS is a constant, check to see if the LHS would be zero without
// using the bits from the RHS. Below, we use knowledge about the RHS to
// simplify the LHS, here we're using information from the LHS to simplify
// the RHS.
if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
APInt LHSZero, LHSOne;
TLO.DAG.ComputeMaskedBits(Op.getOperand(0), NewMask,
LHSZero, LHSOne, Depth+1);
// If the LHS already has zeros where RHSC does, this and is dead.
if ((LHSZero & NewMask) == (~RHSC->getAPIntValue() & NewMask))
return TLO.CombineTo(Op, Op.getOperand(0));
// If any of the set bits in the RHS are known zero on the LHS, shrink
// the constant.
if (TLO.ShrinkDemandedConstant(Op, ~LHSZero & NewMask))
return true;
}
if (SimplifyDemandedBits(Op.getOperand(1), NewMask, KnownZero,
KnownOne, TLO, Depth+1))
return true;
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
if (SimplifyDemandedBits(Op.getOperand(0), ~KnownZero & NewMask,
KnownZero2, KnownOne2, TLO, Depth+1))
return true;
assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?");
// If all of the demanded bits are known one on one side, return the other.
// These bits cannot contribute to the result of the 'and'.
if ((NewMask & ~KnownZero2 & KnownOne) == (~KnownZero2 & NewMask))
return TLO.CombineTo(Op, Op.getOperand(0));
if ((NewMask & ~KnownZero & KnownOne2) == (~KnownZero & NewMask))
return TLO.CombineTo(Op, Op.getOperand(1));
// If all of the demanded bits in the inputs are known zeros, return zero.
if ((NewMask & (KnownZero|KnownZero2)) == NewMask)
return TLO.CombineTo(Op, TLO.DAG.getConstant(0, Op.getValueType()));
// If the RHS is a constant, see if we can simplify it.
if (TLO.ShrinkDemandedConstant(Op, ~KnownZero2 & NewMask))
return true;
// If the operation can be done in a smaller type, do so.
if (TLO.ShrinkDemandedOp(Op, BitWidth, NewMask, dl))
return true;
// Output known-1 bits are only known if set in both the LHS & RHS.
KnownOne &= KnownOne2;
// Output known-0 are known to be clear if zero in either the LHS | RHS.
KnownZero |= KnownZero2;
break;
case ISD::OR:
if (SimplifyDemandedBits(Op.getOperand(1), NewMask, KnownZero,
KnownOne, TLO, Depth+1))
return true;
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
if (SimplifyDemandedBits(Op.getOperand(0), ~KnownOne & NewMask,
KnownZero2, KnownOne2, TLO, Depth+1))
return true;
assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?");
// If all of the demanded bits are known zero on one side, return the other.
// These bits cannot contribute to the result of the 'or'.
if ((NewMask & ~KnownOne2 & KnownZero) == (~KnownOne2 & NewMask))
return TLO.CombineTo(Op, Op.getOperand(0));
if ((NewMask & ~KnownOne & KnownZero2) == (~KnownOne & NewMask))
return TLO.CombineTo(Op, Op.getOperand(1));
// If all of the potentially set bits on one side are known to be set on
// the other side, just use the 'other' side.
if ((NewMask & ~KnownZero & KnownOne2) == (~KnownZero & NewMask))
return TLO.CombineTo(Op, Op.getOperand(0));
if ((NewMask & ~KnownZero2 & KnownOne) == (~KnownZero2 & NewMask))
return TLO.CombineTo(Op, Op.getOperand(1));
// If the RHS is a constant, see if we can simplify it.
if (TLO.ShrinkDemandedConstant(Op, NewMask))
return true;
// If the operation can be done in a smaller type, do so.
if (TLO.ShrinkDemandedOp(Op, BitWidth, NewMask, dl))
return true;
// Output known-0 bits are only known if clear in both the LHS & RHS.
KnownZero &= KnownZero2;
// Output known-1 are known to be set if set in either the LHS | RHS.
KnownOne |= KnownOne2;
break;
case ISD::XOR:
if (SimplifyDemandedBits(Op.getOperand(1), NewMask, KnownZero,
KnownOne, TLO, Depth+1))
return true;
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
if (SimplifyDemandedBits(Op.getOperand(0), NewMask, KnownZero2,
KnownOne2, TLO, Depth+1))
return true;
assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?");
// If all of the demanded bits are known zero on one side, return the other.
// These bits cannot contribute to the result of the 'xor'.
if ((KnownZero & NewMask) == NewMask)
return TLO.CombineTo(Op, Op.getOperand(0));
if ((KnownZero2 & NewMask) == NewMask)
return TLO.CombineTo(Op, Op.getOperand(1));
// If the operation can be done in a smaller type, do so.
if (TLO.ShrinkDemandedOp(Op, BitWidth, NewMask, dl))
return true;
// If all of the unknown bits are known to be zero on one side or the other
// (but not both) turn this into an *inclusive* or.
// e.g. (A & C1)^(B & C2) -> (A & C1)|(B & C2) iff C1&C2 == 0
if ((NewMask & ~KnownZero & ~KnownZero2) == 0)
return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::OR, dl, Op.getValueType(),
Op.getOperand(0),
Op.getOperand(1)));
// Output known-0 bits are known if clear or set in both the LHS & RHS.
KnownZeroOut = (KnownZero & KnownZero2) | (KnownOne & KnownOne2);
// Output known-1 are known to be set if set in only one of the LHS, RHS.
KnownOneOut = (KnownZero & KnownOne2) | (KnownOne & KnownZero2);
// If all of the demanded bits on one side are known, and all of the set
// bits on that side are also known to be set on the other side, turn this
// into an AND, as we know the bits will be cleared.
// e.g. (X | C1) ^ C2 --> (X | C1) & ~C2 iff (C1&C2) == C2
if ((NewMask & (KnownZero|KnownOne)) == NewMask) { // all known
if ((KnownOne & KnownOne2) == KnownOne) {
MVT VT = Op.getValueType();
SDValue ANDC = TLO.DAG.getConstant(~KnownOne & NewMask, VT);
return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::AND, dl, VT,
Op.getOperand(0), ANDC));
}
}
// If the RHS is a constant, see if we can simplify it.
// for XOR, we prefer to force bits to 1 if they will make a -1.
// if we can't force bits, try to shrink constant
if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
APInt Expanded = C->getAPIntValue() | (~NewMask);
// if we can expand it to have all bits set, do it
if (Expanded.isAllOnesValue()) {
if (Expanded != C->getAPIntValue()) {
MVT VT = Op.getValueType();
SDValue New = TLO.DAG.getNode(Op.getOpcode(), dl,VT, Op.getOperand(0),
TLO.DAG.getConstant(Expanded, VT));
return TLO.CombineTo(Op, New);
}
// if it already has all the bits set, nothing to change
// but don't shrink either!
} else if (TLO.ShrinkDemandedConstant(Op, NewMask)) {
return true;
}
}
KnownZero = KnownZeroOut;
KnownOne = KnownOneOut;
break;
case ISD::SELECT:
if (SimplifyDemandedBits(Op.getOperand(2), NewMask, KnownZero,
KnownOne, TLO, Depth+1))
return true;
if (SimplifyDemandedBits(Op.getOperand(1), NewMask, KnownZero2,
KnownOne2, TLO, Depth+1))
return true;
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?");
// If the operands are constants, see if we can simplify them.
if (TLO.ShrinkDemandedConstant(Op, NewMask))
return true;
// Only known if known in both the LHS and RHS.
KnownOne &= KnownOne2;
KnownZero &= KnownZero2;
break;
case ISD::SELECT_CC:
if (SimplifyDemandedBits(Op.getOperand(3), NewMask, KnownZero,
KnownOne, TLO, Depth+1))
return true;
if (SimplifyDemandedBits(Op.getOperand(2), NewMask, KnownZero2,
KnownOne2, TLO, Depth+1))
return true;
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?");
// If the operands are constants, see if we can simplify them.
if (TLO.ShrinkDemandedConstant(Op, NewMask))
return true;
// Only known if known in both the LHS and RHS.
KnownOne &= KnownOne2;
KnownZero &= KnownZero2;
break;
case ISD::SHL:
if (ConstantSDNode *SA = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
unsigned ShAmt = SA->getZExtValue();
SDValue InOp = Op.getOperand(0);
// If the shift count is an invalid immediate, don't do anything.
if (ShAmt >= BitWidth)
break;
// If this is ((X >>u C1) << ShAmt), see if we can simplify this into a
// single shift. We can do this if the bottom bits (which are shifted
// out) are never demanded.
if (InOp.getOpcode() == ISD::SRL &&
isa<ConstantSDNode>(InOp.getOperand(1))) {
if (ShAmt && (NewMask & APInt::getLowBitsSet(BitWidth, ShAmt)) == 0) {
unsigned C1= cast<ConstantSDNode>(InOp.getOperand(1))->getZExtValue();
unsigned Opc = ISD::SHL;
int Diff = ShAmt-C1;
if (Diff < 0) {
Diff = -Diff;
Opc = ISD::SRL;
}
SDValue NewSA =
TLO.DAG.getConstant(Diff, Op.getOperand(1).getValueType());
MVT VT = Op.getValueType();
return TLO.CombineTo(Op, TLO.DAG.getNode(Opc, dl, VT,
InOp.getOperand(0), NewSA));
}
}
if (SimplifyDemandedBits(Op.getOperand(0), NewMask.lshr(ShAmt),
KnownZero, KnownOne, TLO, Depth+1))
return true;
KnownZero <<= SA->getZExtValue();
KnownOne <<= SA->getZExtValue();
// low bits known zero.
KnownZero |= APInt::getLowBitsSet(BitWidth, SA->getZExtValue());
}
break;
case ISD::SRL:
if (ConstantSDNode *SA = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
MVT VT = Op.getValueType();
unsigned ShAmt = SA->getZExtValue();
unsigned VTSize = VT.getSizeInBits();
SDValue InOp = Op.getOperand(0);
// If the shift count is an invalid immediate, don't do anything.
if (ShAmt >= BitWidth)
break;
// If this is ((X << C1) >>u ShAmt), see if we can simplify this into a
// single shift. We can do this if the top bits (which are shifted out)
// are never demanded.
if (InOp.getOpcode() == ISD::SHL &&
isa<ConstantSDNode>(InOp.getOperand(1))) {
if (ShAmt && (NewMask & APInt::getHighBitsSet(VTSize, ShAmt)) == 0) {
unsigned C1= cast<ConstantSDNode>(InOp.getOperand(1))->getZExtValue();
unsigned Opc = ISD::SRL;
int Diff = ShAmt-C1;
if (Diff < 0) {
Diff = -Diff;
Opc = ISD::SHL;
}
SDValue NewSA =
TLO.DAG.getConstant(Diff, Op.getOperand(1).getValueType());
return TLO.CombineTo(Op, TLO.DAG.getNode(Opc, dl, VT,
InOp.getOperand(0), NewSA));
}
}
// Compute the new bits that are at the top now.
if (SimplifyDemandedBits(InOp, (NewMask << ShAmt),
KnownZero, KnownOne, TLO, Depth+1))
return true;
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
KnownZero = KnownZero.lshr(ShAmt);
KnownOne = KnownOne.lshr(ShAmt);
APInt HighBits = APInt::getHighBitsSet(BitWidth, ShAmt);
KnownZero |= HighBits; // High bits known zero.
}
break;
case ISD::SRA:
// If this is an arithmetic shift right and only the low-bit is set, we can
// always convert this into a logical shr, even if the shift amount is
// variable. The low bit of the shift cannot be an input sign bit unless
// the shift amount is >= the size of the datatype, which is undefined.
if (DemandedMask == 1)
return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::SRL, dl, Op.getValueType(),
Op.getOperand(0), Op.getOperand(1)));
if (ConstantSDNode *SA = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
MVT VT = Op.getValueType();
unsigned ShAmt = SA->getZExtValue();
// If the shift count is an invalid immediate, don't do anything.
if (ShAmt >= BitWidth)
break;
APInt InDemandedMask = (NewMask << ShAmt);
// If any of the demanded bits are produced by the sign extension, we also
// demand the input sign bit.
APInt HighBits = APInt::getHighBitsSet(BitWidth, ShAmt);
if (HighBits.intersects(NewMask))
InDemandedMask |= APInt::getSignBit(VT.getSizeInBits());
if (SimplifyDemandedBits(Op.getOperand(0), InDemandedMask,
KnownZero, KnownOne, TLO, Depth+1))
return true;
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
KnownZero = KnownZero.lshr(ShAmt);
KnownOne = KnownOne.lshr(ShAmt);
// Handle the sign bit, adjusted to where it is now in the mask.
APInt SignBit = APInt::getSignBit(BitWidth).lshr(ShAmt);
// If the input sign bit is known to be zero, or if none of the top bits
// are demanded, turn this into an unsigned shift right.
if (KnownZero.intersects(SignBit) || (HighBits & ~NewMask) == HighBits) {
return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::SRL, dl, VT,
Op.getOperand(0),
Op.getOperand(1)));
} else if (KnownOne.intersects(SignBit)) { // New bits are known one.
KnownOne |= HighBits;
}
}
break;
case ISD::SIGN_EXTEND_INREG: {
MVT EVT = cast<VTSDNode>(Op.getOperand(1))->getVT();
// Sign extension. Compute the demanded bits in the result that are not
// present in the input.
APInt NewBits = APInt::getHighBitsSet(BitWidth,
BitWidth - EVT.getSizeInBits()) &
NewMask;
// If none of the extended bits are demanded, eliminate the sextinreg.
if (NewBits == 0)
return TLO.CombineTo(Op, Op.getOperand(0));
APInt InSignBit = APInt::getSignBit(EVT.getSizeInBits());
InSignBit.zext(BitWidth);
APInt InputDemandedBits = APInt::getLowBitsSet(BitWidth,
EVT.getSizeInBits()) &
NewMask;
// Since the sign extended bits are demanded, we know that the sign
// bit is demanded.
InputDemandedBits |= InSignBit;
if (SimplifyDemandedBits(Op.getOperand(0), InputDemandedBits,
KnownZero, KnownOne, TLO, Depth+1))
return true;
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
// If the sign bit of the input is known set or clear, then we know the
// top bits of the result.
// If the input sign bit is known zero, convert this into a zero extension.
if (KnownZero.intersects(InSignBit))
return TLO.CombineTo(Op,
TLO.DAG.getZeroExtendInReg(Op.getOperand(0),dl,EVT));
if (KnownOne.intersects(InSignBit)) { // Input sign bit known set
KnownOne |= NewBits;
KnownZero &= ~NewBits;
} else { // Input sign bit unknown
KnownZero &= ~NewBits;
KnownOne &= ~NewBits;
}
break;
}
case ISD::ZERO_EXTEND: {
unsigned OperandBitWidth = Op.getOperand(0).getValueSizeInBits();
APInt InMask = NewMask;
InMask.trunc(OperandBitWidth);
// If none of the top bits are demanded, convert this into an any_extend.
APInt NewBits =
APInt::getHighBitsSet(BitWidth, BitWidth - OperandBitWidth) & NewMask;
if (!NewBits.intersects(NewMask))
return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::ANY_EXTEND, dl,
Op.getValueType(),
Op.getOperand(0)));
if (SimplifyDemandedBits(Op.getOperand(0), InMask,
KnownZero, KnownOne, TLO, Depth+1))
return true;
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
KnownZero.zext(BitWidth);
KnownOne.zext(BitWidth);
KnownZero |= NewBits;
break;
}
case ISD::SIGN_EXTEND: {
MVT InVT = Op.getOperand(0).getValueType();
unsigned InBits = InVT.getSizeInBits();
APInt InMask = APInt::getLowBitsSet(BitWidth, InBits);
APInt InSignBit = APInt::getBitsSet(BitWidth, InBits - 1, InBits);
APInt NewBits = ~InMask & NewMask;
// If none of the top bits are demanded, convert this into an any_extend.
if (NewBits == 0)
return TLO.CombineTo(Op,TLO.DAG.getNode(ISD::ANY_EXTEND, dl,
Op.getValueType(),
Op.getOperand(0)));
// Since some of the sign extended bits are demanded, we know that the sign
// bit is demanded.
APInt InDemandedBits = InMask & NewMask;
InDemandedBits |= InSignBit;
InDemandedBits.trunc(InBits);
if (SimplifyDemandedBits(Op.getOperand(0), InDemandedBits, KnownZero,
KnownOne, TLO, Depth+1))
return true;
KnownZero.zext(BitWidth);
KnownOne.zext(BitWidth);
// If the sign bit is known zero, convert this to a zero extend.
if (KnownZero.intersects(InSignBit))
return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::ZERO_EXTEND, dl,
Op.getValueType(),
Op.getOperand(0)));
// If the sign bit is known one, the top bits match.
if (KnownOne.intersects(InSignBit)) {
KnownOne |= NewBits;
KnownZero &= ~NewBits;
} else { // Otherwise, top bits aren't known.
KnownOne &= ~NewBits;
KnownZero &= ~NewBits;
}
break;
}
case ISD::ANY_EXTEND: {
unsigned OperandBitWidth = Op.getOperand(0).getValueSizeInBits();
APInt InMask = NewMask;
InMask.trunc(OperandBitWidth);
if (SimplifyDemandedBits(Op.getOperand(0), InMask,
KnownZero, KnownOne, TLO, Depth+1))
return true;
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
KnownZero.zext(BitWidth);
KnownOne.zext(BitWidth);
break;
}
case ISD::TRUNCATE: {
// Simplify the input, using demanded bit information, and compute the known
// zero/one bits live out.
APInt TruncMask = NewMask;
TruncMask.zext(Op.getOperand(0).getValueSizeInBits());
if (SimplifyDemandedBits(Op.getOperand(0), TruncMask,
KnownZero, KnownOne, TLO, Depth+1))
return true;
KnownZero.trunc(BitWidth);
KnownOne.trunc(BitWidth);
// If the input is only used by this truncate, see if we can shrink it based
// on the known demanded bits.
if (Op.getOperand(0).getNode()->hasOneUse()) {
SDValue In = Op.getOperand(0);
unsigned InBitWidth = In.getValueSizeInBits();
switch (In.getOpcode()) {
default: break;
case ISD::SRL:
// Shrink SRL by a constant if none of the high bits shifted in are
// demanded.
if (ConstantSDNode *ShAmt = dyn_cast<ConstantSDNode>(In.getOperand(1))){
APInt HighBits = APInt::getHighBitsSet(InBitWidth,
InBitWidth - BitWidth);
HighBits = HighBits.lshr(ShAmt->getZExtValue());
HighBits.trunc(BitWidth);
if (ShAmt->getZExtValue() < BitWidth && !(HighBits & NewMask)) {
// None of the shifted in bits are needed. Add a truncate of the
// shift input, then shift it.
SDValue NewTrunc = TLO.DAG.getNode(ISD::TRUNCATE, dl,
Op.getValueType(),
In.getOperand(0));
return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::SRL, dl,
Op.getValueType(),
NewTrunc,
In.getOperand(1)));
}
}
break;
}
}
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
break;
}
case ISD::AssertZext: {
MVT VT = cast<VTSDNode>(Op.getOperand(1))->getVT();
APInt InMask = APInt::getLowBitsSet(BitWidth,
VT.getSizeInBits());
if (SimplifyDemandedBits(Op.getOperand(0), InMask & NewMask,
KnownZero, KnownOne, TLO, Depth+1))
return true;
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
KnownZero |= ~InMask & NewMask;
break;
}
case ISD::BIT_CONVERT:
#if 0
// If this is an FP->Int bitcast and if the sign bit is the only thing that
// is demanded, turn this into a FGETSIGN.
if (NewMask == MVT::getIntegerVTSignBit(Op.getValueType()) &&
MVT::isFloatingPoint(Op.getOperand(0).getValueType()) &&
!MVT::isVector(Op.getOperand(0).getValueType())) {
// Only do this xform if FGETSIGN is valid or if before legalize.
if (!TLO.AfterLegalize ||
isOperationLegal(ISD::FGETSIGN, Op.getValueType())) {
// Make a FGETSIGN + SHL to move the sign bit into the appropriate
// place. We expect the SHL to be eliminated by other optimizations.
SDValue Sign = TLO.DAG.getNode(ISD::FGETSIGN, Op.getValueType(),
Op.getOperand(0));
unsigned ShVal = Op.getValueType().getSizeInBits()-1;
SDValue ShAmt = TLO.DAG.getConstant(ShVal, getShiftAmountTy());
return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::SHL, Op.getValueType(),
Sign, ShAmt));
}
}
#endif
break;
case ISD::ADD:
case ISD::MUL:
case ISD::SUB: {
// Add, Sub, and Mul don't demand any bits in positions beyond that
// of the highest bit demanded of them.
APInt LoMask = APInt::getLowBitsSet(BitWidth,
BitWidth - NewMask.countLeadingZeros());
if (SimplifyDemandedBits(Op.getOperand(0), LoMask, KnownZero2,
KnownOne2, TLO, Depth+1))
return true;
if (SimplifyDemandedBits(Op.getOperand(1), LoMask, KnownZero2,
KnownOne2, TLO, Depth+1))
return true;
// See if the operation should be performed at a smaller bit width.
if (TLO.ShrinkDemandedOp(Op, BitWidth, NewMask, dl))
return true;
}
// FALL THROUGH
default:
// Just use ComputeMaskedBits to compute output bits.
TLO.DAG.ComputeMaskedBits(Op, NewMask, KnownZero, KnownOne, Depth);
break;
}
// If we know the value of all of the demanded bits, return this as a
// constant.
if ((NewMask & (KnownZero|KnownOne)) == NewMask)
return TLO.CombineTo(Op, TLO.DAG.getConstant(KnownOne, Op.getValueType()));
return false;
}
/// computeMaskedBitsForTargetNode - Determine which of the bits specified
/// in Mask are known to be either zero or one and return them in the
/// KnownZero/KnownOne bitsets.
void TargetLowering::computeMaskedBitsForTargetNode(const SDValue Op,
const APInt &Mask,
APInt &KnownZero,
APInt &KnownOne,
const SelectionDAG &DAG,
unsigned Depth) const {
assert((Op.getOpcode() >= ISD::BUILTIN_OP_END ||
Op.getOpcode() == ISD::INTRINSIC_WO_CHAIN ||
Op.getOpcode() == ISD::INTRINSIC_W_CHAIN ||
Op.getOpcode() == ISD::INTRINSIC_VOID) &&
"Should use MaskedValueIsZero if you don't know whether Op"
" is a target node!");
KnownZero = KnownOne = APInt(Mask.getBitWidth(), 0);
}
/// ComputeNumSignBitsForTargetNode - This method can be implemented by
/// targets that want to expose additional information about sign bits to the
/// DAG Combiner.
unsigned TargetLowering::ComputeNumSignBitsForTargetNode(SDValue Op,
unsigned Depth) const {
assert((Op.getOpcode() >= ISD::BUILTIN_OP_END ||
Op.getOpcode() == ISD::INTRINSIC_WO_CHAIN ||
Op.getOpcode() == ISD::INTRINSIC_W_CHAIN ||
Op.getOpcode() == ISD::INTRINSIC_VOID) &&
"Should use ComputeNumSignBits if you don't know whether Op"
" is a target node!");
return 1;
}
/// ValueHasExactlyOneBitSet - Test if the given value is known to have exactly
/// one bit set. This differs from ComputeMaskedBits in that it doesn't need to
/// determine which bit is set.
///
static bool ValueHasExactlyOneBitSet(SDValue Val, const SelectionDAG &DAG) {
// A left-shift of a constant one will have exactly one bit set, because
// shifting the bit off the end is undefined.
if (Val.getOpcode() == ISD::SHL)
if (ConstantSDNode *C =
dyn_cast<ConstantSDNode>(Val.getNode()->getOperand(0)))
if (C->getAPIntValue() == 1)
return true;
// Similarly, a right-shift of a constant sign-bit will have exactly
// one bit set.
if (Val.getOpcode() == ISD::SRL)
if (ConstantSDNode *C =
dyn_cast<ConstantSDNode>(Val.getNode()->getOperand(0)))
if (C->getAPIntValue().isSignBit())
return true;
// More could be done here, though the above checks are enough
// to handle some common cases.
// Fall back to ComputeMaskedBits to catch other known cases.
MVT OpVT = Val.getValueType();
unsigned BitWidth = OpVT.getSizeInBits();
APInt Mask = APInt::getAllOnesValue(BitWidth);
APInt KnownZero, KnownOne;
DAG.ComputeMaskedBits(Val, Mask, KnownZero, KnownOne);
return (KnownZero.countPopulation() == BitWidth - 1) &&
(KnownOne.countPopulation() == 1);
}
/// SimplifySetCC - Try to simplify a setcc built with the specified operands
/// and cc. If it is unable to simplify it, return a null SDValue.
SDValue
TargetLowering::SimplifySetCC(MVT VT, SDValue N0, SDValue N1,
ISD::CondCode Cond, bool foldBooleans,
DAGCombinerInfo &DCI, DebugLoc dl) const {
SelectionDAG &DAG = DCI.DAG;
// These setcc operations always fold.
switch (Cond) {
default: break;
case ISD::SETFALSE:
case ISD::SETFALSE2: return DAG.getConstant(0, VT);
case ISD::SETTRUE:
case ISD::SETTRUE2: return DAG.getConstant(1, VT);
}
if (ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.getNode())) {
const APInt &C1 = N1C->getAPIntValue();
if (isa<ConstantSDNode>(N0.getNode())) {
return DAG.FoldSetCC(VT, N0, N1, Cond, dl);
} else {
// If the LHS is '(srl (ctlz x), 5)', the RHS is 0/1, and this is an
// equality comparison, then we're just comparing whether X itself is
// zero.
if (N0.getOpcode() == ISD::SRL && (C1 == 0 || C1 == 1) &&
N0.getOperand(0).getOpcode() == ISD::CTLZ &&
N0.getOperand(1).getOpcode() == ISD::Constant) {
unsigned ShAmt = cast<ConstantSDNode>(N0.getOperand(1))->getZExtValue();
if ((Cond == ISD::SETEQ || Cond == ISD::SETNE) &&
ShAmt == Log2_32(N0.getValueType().getSizeInBits())) {
if ((C1 == 0) == (Cond == ISD::SETEQ)) {
// (srl (ctlz x), 5) == 0 -> X != 0
// (srl (ctlz x), 5) != 1 -> X != 0
Cond = ISD::SETNE;
} else {
// (srl (ctlz x), 5) != 0 -> X == 0
// (srl (ctlz x), 5) == 1 -> X == 0
Cond = ISD::SETEQ;
}
SDValue Zero = DAG.getConstant(0, N0.getValueType());
return DAG.getSetCC(dl, VT, N0.getOperand(0).getOperand(0),
Zero, Cond);
}
}
// If the LHS is '(and load, const)', the RHS is 0,
// the test is for equality or unsigned, and all 1 bits of the const are
// in the same partial word, see if we can shorten the load.
if (DCI.isBeforeLegalize() &&
N0.getOpcode() == ISD::AND && C1 == 0 &&
N0.getNode()->hasOneUse() &&
isa<LoadSDNode>(N0.getOperand(0)) &&
N0.getOperand(0).getNode()->hasOneUse() &&
isa<ConstantSDNode>(N0.getOperand(1))) {
LoadSDNode *Lod = cast<LoadSDNode>(N0.getOperand(0));
uint64_t bestMask = 0;
unsigned bestWidth = 0, bestOffset = 0;
if (!Lod->isVolatile() && Lod->isUnindexed() &&
// FIXME: This uses getZExtValue() below so it only works on i64 and
// below.
N0.getValueType().getSizeInBits() <= 64) {
unsigned origWidth = N0.getValueType().getSizeInBits();
// We can narrow (e.g.) 16-bit extending loads on 32-bit target to
// 8 bits, but have to be careful...
if (Lod->getExtensionType() != ISD::NON_EXTLOAD)
origWidth = Lod->getMemoryVT().getSizeInBits();
uint64_t Mask =cast<ConstantSDNode>(N0.getOperand(1))->getZExtValue();
for (unsigned width = origWidth / 2; width>=8; width /= 2) {
uint64_t newMask = (1ULL << width) - 1;
for (unsigned offset=0; offset<origWidth/width; offset++) {
if ((newMask & Mask) == Mask) {
if (!TD->isLittleEndian())
bestOffset = (origWidth/width - offset - 1) * (width/8);
else
bestOffset = (uint64_t)offset * (width/8);
bestMask = Mask >> (offset * (width/8) * 8);
bestWidth = width;
break;
}
newMask = newMask << width;
}
}
}
if (bestWidth) {
MVT newVT = MVT::getIntegerVT(bestWidth);
if (newVT.isRound()) {
MVT PtrType = Lod->getOperand(1).getValueType();
SDValue Ptr = Lod->getBasePtr();
if (bestOffset != 0)
Ptr = DAG.getNode(ISD::ADD, dl, PtrType, Lod->getBasePtr(),
DAG.getConstant(bestOffset, PtrType));
unsigned NewAlign = MinAlign(Lod->getAlignment(), bestOffset);
SDValue NewLoad = DAG.getLoad(newVT, dl, Lod->getChain(), Ptr,
Lod->getSrcValue(),
Lod->getSrcValueOffset() + bestOffset,
false, NewAlign);
return DAG.getSetCC(dl, VT,
DAG.getNode(ISD::AND, dl, newVT, NewLoad,
DAG.getConstant(bestMask, newVT)),
DAG.getConstant(0LL, newVT), Cond);
}
}
}
// If the LHS is a ZERO_EXTEND, perform the comparison on the input.
if (N0.getOpcode() == ISD::ZERO_EXTEND) {
unsigned InSize = N0.getOperand(0).getValueType().getSizeInBits();
// If the comparison constant has bits in the upper part, the
// zero-extended value could never match.
if (C1.intersects(APInt::getHighBitsSet(C1.getBitWidth(),
C1.getBitWidth() - InSize))) {
switch (Cond) {
case ISD::SETUGT:
case ISD::SETUGE:
case ISD::SETEQ: return DAG.getConstant(0, VT);
case ISD::SETULT:
case ISD::SETULE:
case ISD::SETNE: return DAG.getConstant(1, VT);
case ISD::SETGT:
case ISD::SETGE:
// True if the sign bit of C1 is set.
return DAG.getConstant(C1.isNegative(), VT);
case ISD::SETLT:
case ISD::SETLE:
// True if the sign bit of C1 isn't set.
return DAG.getConstant(C1.isNonNegative(), VT);
default:
break;
}
}
// Otherwise, we can perform the comparison with the low bits.
switch (Cond) {
case ISD::SETEQ:
case ISD::SETNE:
case ISD::SETUGT:
case ISD::SETUGE:
case ISD::SETULT:
case ISD::SETULE:
return DAG.getSetCC(dl, VT, N0.getOperand(0),
DAG.getConstant(APInt(C1).trunc(InSize),
N0.getOperand(0).getValueType()),
Cond);
default:
break; // todo, be more careful with signed comparisons
}
} else if (N0.getOpcode() == ISD::SIGN_EXTEND_INREG &&
(Cond == ISD::SETEQ || Cond == ISD::SETNE)) {
MVT ExtSrcTy = cast<VTSDNode>(N0.getOperand(1))->getVT();
unsigned ExtSrcTyBits = ExtSrcTy.getSizeInBits();
MVT ExtDstTy = N0.getValueType();
unsigned ExtDstTyBits = ExtDstTy.getSizeInBits();
// If the extended part has any inconsistent bits, it cannot ever
// compare equal. In other words, they have to be all ones or all
// zeros.
APInt ExtBits =
APInt::getHighBitsSet(ExtDstTyBits, ExtDstTyBits - ExtSrcTyBits);
if ((C1 & ExtBits) != 0 && (C1 & ExtBits) != ExtBits)
return DAG.getConstant(Cond == ISD::SETNE, VT);
SDValue ZextOp;
MVT Op0Ty = N0.getOperand(0).getValueType();
if (Op0Ty == ExtSrcTy) {
ZextOp = N0.getOperand(0);
} else {
APInt Imm = APInt::getLowBitsSet(ExtDstTyBits, ExtSrcTyBits);
ZextOp = DAG.getNode(ISD::AND, dl, Op0Ty, N0.getOperand(0),
DAG.getConstant(Imm, Op0Ty));
}
if (!DCI.isCalledByLegalizer())
DCI.AddToWorklist(ZextOp.getNode());
// Otherwise, make this a use of a zext.
return DAG.getSetCC(dl, VT, ZextOp,
DAG.getConstant(C1 & APInt::getLowBitsSet(
ExtDstTyBits,
ExtSrcTyBits),
ExtDstTy),
Cond);
} else if ((N1C->isNullValue() || N1C->getAPIntValue() == 1) &&
(Cond == ISD::SETEQ || Cond == ISD::SETNE)) {
// SETCC (SETCC), [0|1], [EQ|NE] -> SETCC
if (N0.getOpcode() == ISD::SETCC) {
bool TrueWhenTrue = (Cond == ISD::SETEQ) ^ (N1C->getZExtValue() != 1);
if (TrueWhenTrue)
return N0;
// Invert the condition.
ISD::CondCode CC = cast<CondCodeSDNode>(N0.getOperand(2))->get();
CC = ISD::getSetCCInverse(CC,
N0.getOperand(0).getValueType().isInteger());
return DAG.getSetCC(dl, VT, N0.getOperand(0), N0.getOperand(1), CC);
}
if ((N0.getOpcode() == ISD::XOR ||
(N0.getOpcode() == ISD::AND &&
N0.getOperand(0).getOpcode() == ISD::XOR &&
N0.getOperand(1) == N0.getOperand(0).getOperand(1))) &&
isa<ConstantSDNode>(N0.getOperand(1)) &&
cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue() == 1) {
// If this is (X^1) == 0/1, swap the RHS and eliminate the xor. We
// can only do this if the top bits are known zero.
unsigned BitWidth = N0.getValueSizeInBits();
if (DAG.MaskedValueIsZero(N0,
APInt::getHighBitsSet(BitWidth,
BitWidth-1))) {
// Okay, get the un-inverted input value.
SDValue Val;
if (N0.getOpcode() == ISD::XOR)
Val = N0.getOperand(0);
else {
assert(N0.getOpcode() == ISD::AND &&
N0.getOperand(0).getOpcode() == ISD::XOR);
// ((X^1)&1)^1 -> X & 1
Val = DAG.getNode(ISD::AND, dl, N0.getValueType(),
N0.getOperand(0).getOperand(0),
N0.getOperand(1));
}
return DAG.getSetCC(dl, VT, Val, N1,
Cond == ISD::SETEQ ? ISD::SETNE : ISD::SETEQ);
}
}
}
APInt MinVal, MaxVal;
unsigned OperandBitSize = N1C->getValueType(0).getSizeInBits();
if (ISD::isSignedIntSetCC(Cond)) {
MinVal = APInt::getSignedMinValue(OperandBitSize);
MaxVal = APInt::getSignedMaxValue(OperandBitSize);
} else {
MinVal = APInt::getMinValue(OperandBitSize);
MaxVal = APInt::getMaxValue(OperandBitSize);
}
// Canonicalize GE/LE comparisons to use GT/LT comparisons.
if (Cond == ISD::SETGE || Cond == ISD::SETUGE) {
if (C1 == MinVal) return DAG.getConstant(1, VT); // X >= MIN --> true
// X >= C0 --> X > (C0-1)
return DAG.getSetCC(dl, VT, N0,
DAG.getConstant(C1-1, N1.getValueType()),
(Cond == ISD::SETGE) ? ISD::SETGT : ISD::SETUGT);
}
if (Cond == ISD::SETLE || Cond == ISD::SETULE) {
if (C1 == MaxVal) return DAG.getConstant(1, VT); // X <= MAX --> true
// X <= C0 --> X < (C0+1)
return DAG.getSetCC(dl, VT, N0,
DAG.getConstant(C1+1, N1.getValueType()),
(Cond == ISD::SETLE) ? ISD::SETLT : ISD::SETULT);
}
if ((Cond == ISD::SETLT || Cond == ISD::SETULT) && C1 == MinVal)
return DAG.getConstant(0, VT); // X < MIN --> false
if ((Cond == ISD::SETGE || Cond == ISD::SETUGE) && C1 == MinVal)
return DAG.getConstant(1, VT); // X >= MIN --> true
if ((Cond == ISD::SETGT || Cond == ISD::SETUGT) && C1 == MaxVal)
return DAG.getConstant(0, VT); // X > MAX --> false
if ((Cond == ISD::SETLE || Cond == ISD::SETULE) && C1 == MaxVal)
return DAG.getConstant(1, VT); // X <= MAX --> true
// Canonicalize setgt X, Min --> setne X, Min
if ((Cond == ISD::SETGT || Cond == ISD::SETUGT) && C1 == MinVal)
return DAG.getSetCC(dl, VT, N0, N1, ISD::SETNE);
// Canonicalize setlt X, Max --> setne X, Max
if ((Cond == ISD::SETLT || Cond == ISD::SETULT) && C1 == MaxVal)
return DAG.getSetCC(dl, VT, N0, N1, ISD::SETNE);
// If we have setult X, 1, turn it into seteq X, 0
if ((Cond == ISD::SETLT || Cond == ISD::SETULT) && C1 == MinVal+1)
return DAG.getSetCC(dl, VT, N0,
DAG.getConstant(MinVal, N0.getValueType()),
ISD::SETEQ);
// If we have setugt X, Max-1, turn it into seteq X, Max
else if ((Cond == ISD::SETGT || Cond == ISD::SETUGT) && C1 == MaxVal-1)
return DAG.getSetCC(dl, VT, N0,
DAG.getConstant(MaxVal, N0.getValueType()),
ISD::SETEQ);
// If we have "setcc X, C0", check to see if we can shrink the immediate
// by changing cc.
// SETUGT X, SINTMAX -> SETLT X, 0
if (Cond == ISD::SETUGT &&
C1 == APInt::getSignedMaxValue(OperandBitSize))
return DAG.getSetCC(dl, VT, N0,
DAG.getConstant(0, N1.getValueType()),
ISD::SETLT);
// SETULT X, SINTMIN -> SETGT X, -1
if (Cond == ISD::SETULT &&
C1 == APInt::getSignedMinValue(OperandBitSize)) {
SDValue ConstMinusOne =
DAG.getConstant(APInt::getAllOnesValue(OperandBitSize),
N1.getValueType());
return DAG.getSetCC(dl, VT, N0, ConstMinusOne, ISD::SETGT);
}
// Fold bit comparisons when we can.
if ((Cond == ISD::SETEQ || Cond == ISD::SETNE) &&
VT == N0.getValueType() && N0.getOpcode() == ISD::AND)
if (ConstantSDNode *AndRHS =
dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
MVT ShiftTy = DCI.isBeforeLegalize() ?
getPointerTy() : getShiftAmountTy();
if (Cond == ISD::SETNE && C1 == 0) {// (X & 8) != 0 --> (X & 8) >> 3
// Perform the xform if the AND RHS is a single bit.
if (isPowerOf2_64(AndRHS->getZExtValue())) {
return DAG.getNode(ISD::SRL, dl, VT, N0,
DAG.getConstant(Log2_64(AndRHS->getZExtValue()),
ShiftTy));
}
} else if (Cond == ISD::SETEQ && C1 == AndRHS->getZExtValue()) {
// (X & 8) == 8 --> (X & 8) >> 3
// Perform the xform if C1 is a single bit.
if (C1.isPowerOf2()) {
return DAG.getNode(ISD::SRL, dl, VT, N0,
DAG.getConstant(C1.logBase2(), ShiftTy));
}
}
}
}
} else if (isa<ConstantSDNode>(N0.getNode())) {
// Ensure that the constant occurs on the RHS.
return DAG.getSetCC(dl, VT, N1, N0, ISD::getSetCCSwappedOperands(Cond));
}
if (isa<ConstantFPSDNode>(N0.getNode())) {
// Constant fold or commute setcc.
SDValue O = DAG.FoldSetCC(VT, N0, N1, Cond, dl);
if (O.getNode()) return O;
} else if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(N1.getNode())) {
// If the RHS of an FP comparison is a constant, simplify it away in
// some cases.
if (CFP->getValueAPF().isNaN()) {
// If an operand is known to be a nan, we can fold it.
switch (ISD::getUnorderedFlavor(Cond)) {
default: assert(0 && "Unknown flavor!");
case 0: // Known false.
return DAG.getConstant(0, VT);
case 1: // Known true.
return DAG.getConstant(1, VT);
case 2: // Undefined.
return DAG.getUNDEF(VT);
}
}
// Otherwise, we know the RHS is not a NaN. Simplify the node to drop the
// constant if knowing that the operand is non-nan is enough. We prefer to
// have SETO(x,x) instead of SETO(x, 0.0) because this avoids having to
// materialize 0.0.
if (Cond == ISD::SETO || Cond == ISD::SETUO)
return DAG.getSetCC(dl, VT, N0, N0, Cond);
}
if (N0 == N1) {
// We can always fold X == X for integer setcc's.
if (N0.getValueType().isInteger())
return DAG.getConstant(ISD::isTrueWhenEqual(Cond), VT);
unsigned UOF = ISD::getUnorderedFlavor(Cond);
if (UOF == 2) // FP operators that are undefined on NaNs.
return DAG.getConstant(ISD::isTrueWhenEqual(Cond), VT);
if (UOF == unsigned(ISD::isTrueWhenEqual(Cond)))
return DAG.getConstant(UOF, VT);
// Otherwise, we can't fold it. However, we can simplify it to SETUO/SETO
// if it is not already.
ISD::CondCode NewCond = UOF == 0 ? ISD::SETO : ISD::SETUO;
if (NewCond != Cond)
return DAG.getSetCC(dl, VT, N0, N1, NewCond);
}
if ((Cond == ISD::SETEQ || Cond == ISD::SETNE) &&
N0.getValueType().isInteger()) {
if (N0.getOpcode() == ISD::ADD || N0.getOpcode() == ISD::SUB ||
N0.getOpcode() == ISD::XOR) {
// Simplify (X+Y) == (X+Z) --> Y == Z
if (N0.getOpcode() == N1.getOpcode()) {
if (N0.getOperand(0) == N1.getOperand(0))
return DAG.getSetCC(dl, VT, N0.getOperand(1), N1.getOperand(1), Cond);
if (N0.getOperand(1) == N1.getOperand(1))
return DAG.getSetCC(dl, VT, N0.getOperand(0), N1.getOperand(0), Cond);
if (DAG.isCommutativeBinOp(N0.getOpcode())) {
// If X op Y == Y op X, try other combinations.
if (N0.getOperand(0) == N1.getOperand(1))
return DAG.getSetCC(dl, VT, N0.getOperand(1), N1.getOperand(0),
Cond);
if (N0.getOperand(1) == N1.getOperand(0))
return DAG.getSetCC(dl, VT, N0.getOperand(0), N1.getOperand(1),
Cond);
}
}
if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(N1)) {
if (ConstantSDNode *LHSR = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
// Turn (X+C1) == C2 --> X == C2-C1
if (N0.getOpcode() == ISD::ADD && N0.getNode()->hasOneUse()) {
return DAG.getSetCC(dl, VT, N0.getOperand(0),
DAG.getConstant(RHSC->getAPIntValue()-
LHSR->getAPIntValue(),
N0.getValueType()), Cond);
}
// Turn (X^C1) == C2 into X == C1^C2 iff X&~C1 = 0.
if (N0.getOpcode() == ISD::XOR)
// If we know that all of the inverted bits are zero, don't bother
// performing the inversion.
if (DAG.MaskedValueIsZero(N0.getOperand(0), ~LHSR->getAPIntValue()))
return
DAG.getSetCC(dl, VT, N0.getOperand(0),
DAG.getConstant(LHSR->getAPIntValue() ^
RHSC->getAPIntValue(),
N0.getValueType()),
Cond);
}
// Turn (C1-X) == C2 --> X == C1-C2
if (ConstantSDNode *SUBC = dyn_cast<ConstantSDNode>(N0.getOperand(0))) {
if (N0.getOpcode() == ISD::SUB && N0.getNode()->hasOneUse()) {
return
DAG.getSetCC(dl, VT, N0.getOperand(1),
DAG.getConstant(SUBC->getAPIntValue() -
RHSC->getAPIntValue(),
N0.getValueType()),
Cond);
}
}
}
// Simplify (X+Z) == X --> Z == 0
if (N0.getOperand(0) == N1)
return DAG.getSetCC(dl, VT, N0.getOperand(1),
DAG.getConstant(0, N0.getValueType()), Cond);
if (N0.getOperand(1) == N1) {
if (DAG.isCommutativeBinOp(N0.getOpcode()))
return DAG.getSetCC(dl, VT, N0.getOperand(0),
DAG.getConstant(0, N0.getValueType()), Cond);
else if (N0.getNode()->hasOneUse()) {
assert(N0.getOpcode() == ISD::SUB && "Unexpected operation!");
// (Z-X) == X --> Z == X<<1
SDValue SH = DAG.getNode(ISD::SHL, dl, N1.getValueType(),
N1,
DAG.getConstant(1, getShiftAmountTy()));
if (!DCI.isCalledByLegalizer())
DCI.AddToWorklist(SH.getNode());
return DAG.getSetCC(dl, VT, N0.getOperand(0), SH, Cond);
}
}
}
if (N1.getOpcode() == ISD::ADD || N1.getOpcode() == ISD::SUB ||
N1.getOpcode() == ISD::XOR) {
// Simplify X == (X+Z) --> Z == 0
if (N1.getOperand(0) == N0) {
return DAG.getSetCC(dl, VT, N1.getOperand(1),
DAG.getConstant(0, N1.getValueType()), Cond);
} else if (N1.getOperand(1) == N0) {
if (DAG.isCommutativeBinOp(N1.getOpcode())) {
return DAG.getSetCC(dl, VT, N1.getOperand(0),
DAG.getConstant(0, N1.getValueType()), Cond);
} else if (N1.getNode()->hasOneUse()) {
assert(N1.getOpcode() == ISD::SUB && "Unexpected operation!");
// X == (Z-X) --> X<<1 == Z
SDValue SH = DAG.getNode(ISD::SHL, dl, N1.getValueType(), N0,
DAG.getConstant(1, getShiftAmountTy()));
if (!DCI.isCalledByLegalizer())
DCI.AddToWorklist(SH.getNode());
return DAG.getSetCC(dl, VT, SH, N1.getOperand(0), Cond);
}
}
}
// Simplify x&y == y to x&y != 0 if y has exactly one bit set.
// Note that where y is variable and is known to have at most
// one bit set (for example, if it is z&1) we cannot do this;
// the expressions are not equivalent when y==0.
if (N0.getOpcode() == ISD::AND)
if (N0.getOperand(0) == N1 || N0.getOperand(1) == N1) {
if (ValueHasExactlyOneBitSet(N1, DAG)) {
Cond = ISD::getSetCCInverse(Cond, /*isInteger=*/true);
SDValue Zero = DAG.getConstant(0, N1.getValueType());
return DAG.getSetCC(dl, VT, N0, Zero, Cond);
}
}
if (N1.getOpcode() == ISD::AND)
if (N1.getOperand(0) == N0 || N1.getOperand(1) == N0) {
if (ValueHasExactlyOneBitSet(N0, DAG)) {
Cond = ISD::getSetCCInverse(Cond, /*isInteger=*/true);
SDValue Zero = DAG.getConstant(0, N0.getValueType());
return DAG.getSetCC(dl, VT, N1, Zero, Cond);
}
}
}
// Fold away ALL boolean setcc's.
SDValue Temp;
if (N0.getValueType() == MVT::i1 && foldBooleans) {
switch (Cond) {
default: assert(0 && "Unknown integer setcc!");
case ISD::SETEQ: // X == Y -> ~(X^Y)
Temp = DAG.getNode(ISD::XOR, dl, MVT::i1, N0, N1);
N0 = DAG.getNOT(dl, Temp, MVT::i1);
if (!DCI.isCalledByLegalizer())
DCI.AddToWorklist(Temp.getNode());
break;
case ISD::SETNE: // X != Y --> (X^Y)
N0 = DAG.getNode(ISD::XOR, dl, MVT::i1, N0, N1);
break;
case ISD::SETGT: // X >s Y --> X == 0 & Y == 1 --> ~X & Y
case ISD::SETULT: // X <u Y --> X == 0 & Y == 1 --> ~X & Y
Temp = DAG.getNOT(dl, N0, MVT::i1);
N0 = DAG.getNode(ISD::AND, dl, MVT::i1, N1, Temp);
if (!DCI.isCalledByLegalizer())
DCI.AddToWorklist(Temp.getNode());
break;
case ISD::SETLT: // X <s Y --> X == 1 & Y == 0 --> ~Y & X
case ISD::SETUGT: // X >u Y --> X == 1 & Y == 0 --> ~Y & X
Temp = DAG.getNOT(dl, N1, MVT::i1);
N0 = DAG.getNode(ISD::AND, dl, MVT::i1, N0, Temp);
if (!DCI.isCalledByLegalizer())
DCI.AddToWorklist(Temp.getNode());
break;
case ISD::SETULE: // X <=u Y --> X == 0 | Y == 1 --> ~X | Y
case ISD::SETGE: // X >=s Y --> X == 0 | Y == 1 --> ~X | Y
Temp = DAG.getNOT(dl, N0, MVT::i1);
N0 = DAG.getNode(ISD::OR, dl, MVT::i1, N1, Temp);
if (!DCI.isCalledByLegalizer())
DCI.AddToWorklist(Temp.getNode());
break;
case ISD::SETUGE: // X >=u Y --> X == 1 | Y == 0 --> ~Y | X
case ISD::SETLE: // X <=s Y --> X == 1 | Y == 0 --> ~Y | X
Temp = DAG.getNOT(dl, N1, MVT::i1);
N0 = DAG.getNode(ISD::OR, dl, MVT::i1, N0, Temp);
break;
}
if (VT != MVT::i1) {
if (!DCI.isCalledByLegalizer())
DCI.AddToWorklist(N0.getNode());
// FIXME: If running after legalize, we probably can't do this.
N0 = DAG.getNode(ISD::ZERO_EXTEND, dl, VT, N0);
}
return N0;
}
// Could not fold it.
return SDValue();
}
/// isGAPlusOffset - Returns true (and the GlobalValue and the offset) if the
/// node is a GlobalAddress + offset.
bool TargetLowering::isGAPlusOffset(SDNode *N, GlobalValue* &GA,
int64_t &Offset) const {
if (isa<GlobalAddressSDNode>(N)) {
GlobalAddressSDNode *GASD = cast<GlobalAddressSDNode>(N);
GA = GASD->getGlobal();
Offset += GASD->getOffset();
return true;
}
if (N->getOpcode() == ISD::ADD) {
SDValue N1 = N->getOperand(0);
SDValue N2 = N->getOperand(1);
if (isGAPlusOffset(N1.getNode(), GA, Offset)) {
ConstantSDNode *V = dyn_cast<ConstantSDNode>(N2);
if (V) {
Offset += V->getSExtValue();
return true;
}
} else if (isGAPlusOffset(N2.getNode(), GA, Offset)) {
ConstantSDNode *V = dyn_cast<ConstantSDNode>(N1);
if (V) {
Offset += V->getSExtValue();
return true;
}
}
}
return false;
}
/// isConsecutiveLoad - Return true if LD (which must be a LoadSDNode) is
/// loading 'Bytes' bytes from a location that is 'Dist' units away from the
/// location that the 'Base' load is loading from.
bool TargetLowering::isConsecutiveLoad(SDNode *LD, SDNode *Base,
unsigned Bytes, int Dist,
const MachineFrameInfo *MFI) const {
if (LD->getOperand(0).getNode() != Base->getOperand(0).getNode())
return false;
MVT VT = LD->getValueType(0);
if (VT.getSizeInBits() / 8 != Bytes)
return false;
SDValue Loc = LD->getOperand(1);
SDValue BaseLoc = Base->getOperand(1);
if (Loc.getOpcode() == ISD::FrameIndex) {
if (BaseLoc.getOpcode() != ISD::FrameIndex)
return false;
int FI = cast<FrameIndexSDNode>(Loc)->getIndex();
int BFI = cast<FrameIndexSDNode>(BaseLoc)->getIndex();
int FS = MFI->getObjectSize(FI);
int BFS = MFI->getObjectSize(BFI);
if (FS != BFS || FS != (int)Bytes) return false;
return MFI->getObjectOffset(FI) == (MFI->getObjectOffset(BFI) + Dist*Bytes);
}
GlobalValue *GV1 = NULL;
GlobalValue *GV2 = NULL;
int64_t Offset1 = 0;
int64_t Offset2 = 0;
bool isGA1 = isGAPlusOffset(Loc.getNode(), GV1, Offset1);
bool isGA2 = isGAPlusOffset(BaseLoc.getNode(), GV2, Offset2);
if (isGA1 && isGA2 && GV1 == GV2)
return Offset1 == (Offset2 + Dist*Bytes);
return false;
}
SDValue TargetLowering::
PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const {
// Default implementation: no optimization.
return SDValue();
}
//===----------------------------------------------------------------------===//
// Inline Assembler Implementation Methods
//===----------------------------------------------------------------------===//
TargetLowering::ConstraintType
TargetLowering::getConstraintType(const std::string &Constraint) const {
// FIXME: lots more standard ones to handle.
if (Constraint.size() == 1) {
switch (Constraint[0]) {
default: break;
case 'r': return C_RegisterClass;
case 'm': // memory
case 'o': // offsetable
case 'V': // not offsetable
return C_Memory;
case 'i': // Simple Integer or Relocatable Constant
case 'n': // Simple Integer
case 's': // Relocatable Constant
case 'X': // Allow ANY value.
case 'I': // Target registers.
case 'J':
case 'K':
case 'L':
case 'M':
case 'N':
case 'O':
case 'P':
return C_Other;
}
}
if (Constraint.size() > 1 && Constraint[0] == '{' &&
Constraint[Constraint.size()-1] == '}')
return C_Register;
return C_Unknown;
}
/// LowerXConstraint - try to replace an X constraint, which matches anything,
/// with another that has more specific requirements based on the type of the
/// corresponding operand.
const char *TargetLowering::LowerXConstraint(MVT ConstraintVT) const{
if (ConstraintVT.isInteger())
return "r";
if (ConstraintVT.isFloatingPoint())
return "f"; // works for many targets
return 0;
}
/// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
/// vector. If it is invalid, don't add anything to Ops.
void TargetLowering::LowerAsmOperandForConstraint(SDValue Op,
char ConstraintLetter,
bool hasMemory,
std::vector<SDValue> &Ops,
SelectionDAG &DAG) const {
switch (ConstraintLetter) {
default: break;
case 'X': // Allows any operand; labels (basic block) use this.
if (Op.getOpcode() == ISD::BasicBlock) {
Ops.push_back(Op);
return;
}
// fall through
case 'i': // Simple Integer or Relocatable Constant
case 'n': // Simple Integer
case 's': { // Relocatable Constant
// These operands are interested in values of the form (GV+C), where C may
// be folded in as an offset of GV, or it may be explicitly added. Also, it
// is possible and fine if either GV or C are missing.
ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op);
GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(Op);
// If we have "(add GV, C)", pull out GV/C
if (Op.getOpcode() == ISD::ADD) {
C = dyn_cast<ConstantSDNode>(Op.getOperand(1));
GA = dyn_cast<GlobalAddressSDNode>(Op.getOperand(0));
if (C == 0 || GA == 0) {
C = dyn_cast<ConstantSDNode>(Op.getOperand(0));
GA = dyn_cast<GlobalAddressSDNode>(Op.getOperand(1));
}
if (C == 0 || GA == 0)
C = 0, GA = 0;
}
// If we find a valid operand, map to the TargetXXX version so that the
// value itself doesn't get selected.
if (GA) { // Either &GV or &GV+C
if (ConstraintLetter != 'n') {
int64_t Offs = GA->getOffset();
if (C) Offs += C->getZExtValue();
Ops.push_back(DAG.getTargetGlobalAddress(GA->getGlobal(),
Op.getValueType(), Offs));
return;
}
}
if (C) { // just C, no GV.
// Simple constants are not allowed for 's'.
if (ConstraintLetter != 's') {
// gcc prints these as sign extended. Sign extend value to 64 bits
// now; without this it would get ZExt'd later in
// ScheduleDAGSDNodes::EmitNode, which is very generic.
Ops.push_back(DAG.getTargetConstant(C->getAPIntValue().getSExtValue(),
MVT::i64));
return;
}
}
break;
}
}
}
std::vector<unsigned> TargetLowering::
getRegClassForInlineAsmConstraint(const std::string &Constraint,
MVT VT) const {
return std::vector<unsigned>();
}
std::pair<unsigned, const TargetRegisterClass*> TargetLowering::
getRegForInlineAsmConstraint(const std::string &Constraint,
MVT VT) const {
if (Constraint[0] != '{')
return std::pair<unsigned, const TargetRegisterClass*>(0, 0);
assert(*(Constraint.end()-1) == '}' && "Not a brace enclosed constraint?");
// Remove the braces from around the name.
std::string RegName(Constraint.begin()+1, Constraint.end()-1);
// Figure out which register class contains this reg.
const TargetRegisterInfo *RI = TM.getRegisterInfo();
for (TargetRegisterInfo::regclass_iterator RCI = RI->regclass_begin(),
E = RI->regclass_end(); RCI != E; ++RCI) {
const TargetRegisterClass *RC = *RCI;
// If none of the the value types for this register class are valid, we
// can't use it. For example, 64-bit reg classes on 32-bit targets.
bool isLegal = false;
for (TargetRegisterClass::vt_iterator I = RC->vt_begin(), E = RC->vt_end();
I != E; ++I) {
if (isTypeLegal(*I)) {
isLegal = true;
break;
}
}
if (!isLegal) continue;
for (TargetRegisterClass::iterator I = RC->begin(), E = RC->end();
I != E; ++I) {
if (StringsEqualNoCase(RegName, RI->get(*I).AsmName))
return std::make_pair(*I, RC);
}
}
return std::pair<unsigned, const TargetRegisterClass*>(0, 0);
}
//===----------------------------------------------------------------------===//
// Constraint Selection.
/// isMatchingInputConstraint - Return true of this is an input operand that is
/// a matching constraint like "4".
bool TargetLowering::AsmOperandInfo::isMatchingInputConstraint() const {
assert(!ConstraintCode.empty() && "No known constraint!");
return isdigit(ConstraintCode[0]);
}
/// getMatchedOperand - If this is an input matching constraint, this method
/// returns the output operand it matches.
unsigned TargetLowering::AsmOperandInfo::getMatchedOperand() const {
assert(!ConstraintCode.empty() && "No known constraint!");
return atoi(ConstraintCode.c_str());
}
/// getConstraintGenerality - Return an integer indicating how general CT
/// is.
static unsigned getConstraintGenerality(TargetLowering::ConstraintType CT) {
switch (CT) {
default: assert(0 && "Unknown constraint type!");
case TargetLowering::C_Other:
case TargetLowering::C_Unknown:
return 0;
case TargetLowering::C_Register:
return 1;
case TargetLowering::C_RegisterClass:
return 2;
case TargetLowering::C_Memory:
return 3;
}
}
/// ChooseConstraint - If there are multiple different constraints that we
/// could pick for this operand (e.g. "imr") try to pick the 'best' one.
/// This is somewhat tricky: constraints fall into four classes:
/// Other -> immediates and magic values
/// Register -> one specific register
/// RegisterClass -> a group of regs
/// Memory -> memory
/// Ideally, we would pick the most specific constraint possible: if we have
/// something that fits into a register, we would pick it. The problem here
/// is that if we have something that could either be in a register or in
/// memory that use of the register could cause selection of *other*
/// operands to fail: they might only succeed if we pick memory. Because of
/// this the heuristic we use is:
///
/// 1) If there is an 'other' constraint, and if the operand is valid for
/// that constraint, use it. This makes us take advantage of 'i'
/// constraints when available.
/// 2) Otherwise, pick the most general constraint present. This prefers
/// 'm' over 'r', for example.
///
static void ChooseConstraint(TargetLowering::AsmOperandInfo &OpInfo,
bool hasMemory, const TargetLowering &TLI,
SDValue Op, SelectionDAG *DAG) {
assert(OpInfo.Codes.size() > 1 && "Doesn't have multiple constraint options");
unsigned BestIdx = 0;
TargetLowering::ConstraintType BestType = TargetLowering::C_Unknown;
int BestGenerality = -1;
// Loop over the options, keeping track of the most general one.
for (unsigned i = 0, e = OpInfo.Codes.size(); i != e; ++i) {
TargetLowering::ConstraintType CType =
TLI.getConstraintType(OpInfo.Codes[i]);
// If this is an 'other' constraint, see if the operand is valid for it.
// For example, on X86 we might have an 'rI' constraint. If the operand
// is an integer in the range [0..31] we want to use I (saving a load
// of a register), otherwise we must use 'r'.
if (CType == TargetLowering::C_Other && Op.getNode()) {
assert(OpInfo.Codes[i].size() == 1 &&
"Unhandled multi-letter 'other' constraint");
std::vector<SDValue> ResultOps;
TLI.LowerAsmOperandForConstraint(Op, OpInfo.Codes[i][0], hasMemory,
ResultOps, *DAG);
if (!ResultOps.empty()) {
BestType = CType;
BestIdx = i;
break;
}
}
// This constraint letter is more general than the previous one, use it.
int Generality = getConstraintGenerality(CType);
if (Generality > BestGenerality) {
BestType = CType;
BestIdx = i;
BestGenerality = Generality;
}
}
OpInfo.ConstraintCode = OpInfo.Codes[BestIdx];
OpInfo.ConstraintType = BestType;
}
/// ComputeConstraintToUse - Determines the constraint code and constraint
/// type to use for the specific AsmOperandInfo, setting
/// OpInfo.ConstraintCode and OpInfo.ConstraintType.
void TargetLowering::ComputeConstraintToUse(AsmOperandInfo &OpInfo,
SDValue Op,
bool hasMemory,
SelectionDAG *DAG) const {
assert(!OpInfo.Codes.empty() && "Must have at least one constraint");
// Single-letter constraints ('r') are very common.
if (OpInfo.Codes.size() == 1) {
OpInfo.ConstraintCode = OpInfo.Codes[0];
OpInfo.ConstraintType = getConstraintType(OpInfo.ConstraintCode);
} else {
ChooseConstraint(OpInfo, hasMemory, *this, Op, DAG);
}
// 'X' matches anything.
if (OpInfo.ConstraintCode == "X" && OpInfo.CallOperandVal) {
// Labels and constants are handled elsewhere ('X' is the only thing
// that matches labels).
if (isa<BasicBlock>(OpInfo.CallOperandVal) ||
isa<ConstantInt>(OpInfo.CallOperandVal))
return;
// Otherwise, try to resolve it to something we know about by looking at
// the actual operand type.
if (const char *Repl = LowerXConstraint(OpInfo.ConstraintVT)) {
OpInfo.ConstraintCode = Repl;
OpInfo.ConstraintType = getConstraintType(OpInfo.ConstraintCode);
}
}
}
//===----------------------------------------------------------------------===//
// Loop Strength Reduction hooks
//===----------------------------------------------------------------------===//
/// isLegalAddressingMode - Return true if the addressing mode represented
/// by AM is legal for this target, for a load/store of the specified type.
bool TargetLowering::isLegalAddressingMode(const AddrMode &AM,
const Type *Ty) const {
// The default implementation of this implements a conservative RISCy, r+r and
// r+i addr mode.
// Allows a sign-extended 16-bit immediate field.
if (AM.BaseOffs <= -(1LL << 16) || AM.BaseOffs >= (1LL << 16)-1)
return false;
// No global is ever allowed as a base.
if (AM.BaseGV)
return false;
// Only support r+r,
switch (AM.Scale) {
case 0: // "r+i" or just "i", depending on HasBaseReg.
break;
case 1:
if (AM.HasBaseReg && AM.BaseOffs) // "r+r+i" is not allowed.
return false;
// Otherwise we have r+r or r+i.
break;
case 2:
if (AM.HasBaseReg || AM.BaseOffs) // 2*r+r or 2*r+i is not allowed.
return false;
// Allow 2*r as r+r.
break;
}
return true;
}
/// BuildSDIVSequence - Given an ISD::SDIV node expressing a divide by constant,
/// return a DAG expression to select that will generate the same value by
/// multiplying by a magic number. See:
/// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
SDValue TargetLowering::BuildSDIV(SDNode *N, SelectionDAG &DAG,
std::vector<SDNode*>* Created) const {
MVT VT = N->getValueType(0);
DebugLoc dl= N->getDebugLoc();
// Check to see if we can do this.
// FIXME: We should be more aggressive here.
if (!isTypeLegal(VT))
return SDValue();
APInt d = cast<ConstantSDNode>(N->getOperand(1))->getAPIntValue();
APInt::ms magics = d.magic();
// Multiply the numerator (operand 0) by the magic value
// FIXME: We should support doing a MUL in a wider type
SDValue Q;
if (isOperationLegalOrCustom(ISD::MULHS, VT))
Q = DAG.getNode(ISD::MULHS, dl, VT, N->getOperand(0),
DAG.getConstant(magics.m, VT));
else if (isOperationLegalOrCustom(ISD::SMUL_LOHI, VT))
Q = SDValue(DAG.getNode(ISD::SMUL_LOHI, dl, DAG.getVTList(VT, VT),
N->getOperand(0),
DAG.getConstant(magics.m, VT)).getNode(), 1);
else
return SDValue(); // No mulhs or equvialent
// If d > 0 and m < 0, add the numerator
if (d.isStrictlyPositive() && magics.m.isNegative()) {
Q = DAG.getNode(ISD::ADD, dl, VT, Q, N->getOperand(0));
if (Created)
Created->push_back(Q.getNode());
}
// If d < 0 and m > 0, subtract the numerator.
if (d.isNegative() && magics.m.isStrictlyPositive()) {
Q = DAG.getNode(ISD::SUB, dl, VT, Q, N->getOperand(0));
if (Created)
Created->push_back(Q.getNode());
}
// Shift right algebraic if shift value is nonzero
if (magics.s > 0) {
Q = DAG.getNode(ISD::SRA, dl, VT, Q,
DAG.getConstant(magics.s, getShiftAmountTy()));
if (Created)
Created->push_back(Q.getNode());
}
// Extract the sign bit and add it to the quotient
SDValue T =
DAG.getNode(ISD::SRL, dl, VT, Q, DAG.getConstant(VT.getSizeInBits()-1,
getShiftAmountTy()));
if (Created)
Created->push_back(T.getNode());
return DAG.getNode(ISD::ADD, dl, VT, Q, T);
}
/// BuildUDIVSequence - Given an ISD::UDIV node expressing a divide by constant,
/// return a DAG expression to select that will generate the same value by
/// multiplying by a magic number. See:
/// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
SDValue TargetLowering::BuildUDIV(SDNode *N, SelectionDAG &DAG,
std::vector<SDNode*>* Created) const {
MVT VT = N->getValueType(0);
DebugLoc dl = N->getDebugLoc();
// Check to see if we can do this.
// FIXME: We should be more aggressive here.
if (!isTypeLegal(VT))
return SDValue();
// FIXME: We should use a narrower constant when the upper
// bits are known to be zero.
ConstantSDNode *N1C = cast<ConstantSDNode>(N->getOperand(1));
APInt::mu magics = N1C->getAPIntValue().magicu();
// Multiply the numerator (operand 0) by the magic value
// FIXME: We should support doing a MUL in a wider type
SDValue Q;
if (isOperationLegalOrCustom(ISD::MULHU, VT))
Q = DAG.getNode(ISD::MULHU, dl, VT, N->getOperand(0),
DAG.getConstant(magics.m, VT));
else if (isOperationLegalOrCustom(ISD::UMUL_LOHI, VT))
Q = SDValue(DAG.getNode(ISD::UMUL_LOHI, dl, DAG.getVTList(VT, VT),
N->getOperand(0),
DAG.getConstant(magics.m, VT)).getNode(), 1);
else
return SDValue(); // No mulhu or equvialent
if (Created)
Created->push_back(Q.getNode());
if (magics.a == 0) {
assert(magics.s < N1C->getAPIntValue().getBitWidth() &&
"We shouldn't generate an undefined shift!");
return DAG.getNode(ISD::SRL, dl, VT, Q,
DAG.getConstant(magics.s, getShiftAmountTy()));
} else {
SDValue NPQ = DAG.getNode(ISD::SUB, dl, VT, N->getOperand(0), Q);
if (Created)
Created->push_back(NPQ.getNode());
NPQ = DAG.getNode(ISD::SRL, dl, VT, NPQ,
DAG.getConstant(1, getShiftAmountTy()));
if (Created)
Created->push_back(NPQ.getNode());
NPQ = DAG.getNode(ISD::ADD, dl, VT, NPQ, Q);
if (Created)
Created->push_back(NPQ.getNode());
return DAG.getNode(ISD::SRL, dl, VT, NPQ,
DAG.getConstant(magics.s-1, getShiftAmountTy()));
}
}
/// IgnoreHarmlessInstructions - Ignore instructions between a CALL and RET
/// node that don't prevent tail call optimization.
static SDValue IgnoreHarmlessInstructions(SDValue node) {
// Found call return.
if (node.getOpcode() == ISD::CALL) return node;
// Ignore MERGE_VALUES. Will have at least one operand.
if (node.getOpcode() == ISD::MERGE_VALUES)
return IgnoreHarmlessInstructions(node.getOperand(0));
// Ignore ANY_EXTEND node.
if (node.getOpcode() == ISD::ANY_EXTEND)
return IgnoreHarmlessInstructions(node.getOperand(0));
if (node.getOpcode() == ISD::TRUNCATE)
return IgnoreHarmlessInstructions(node.getOperand(0));
// Any other node type.
return node;
}
bool TargetLowering::CheckTailCallReturnConstraints(CallSDNode *TheCall,
SDValue Ret) {
unsigned NumOps = Ret.getNumOperands();
// ISD::CALL results:(value0, ..., valuen, chain)
// ISD::RET operands:(chain, value0, flag0, ..., valuen, flagn)
// Value return:
// Check that operand of the RET node sources from the CALL node. The RET node
// has at least two operands. Operand 0 holds the chain. Operand 1 holds the
// value.
if (NumOps > 1 &&
IgnoreHarmlessInstructions(Ret.getOperand(1)) == SDValue(TheCall,0))
return true;
// void return: The RET node has the chain result value of the CALL node as
// input.
if (NumOps == 1 &&
Ret.getOperand(0) == SDValue(TheCall, TheCall->getNumValues()-1))
return true;
return false;
}
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