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Commit Graph

281 Commits

Author SHA1 Message Date
Craig Topper
4e9457fd7d Use llvm::array_lengthof to replace sizeof(array)/sizeof(array[0]).
llvm-svn: 186301
2013-07-15 04:27:47 +00:00
Ulrich Weigand
b664c03f18 [PowerPC] Revert r185476 and fix up TLS variant kinds
In the commit message to r185476 I wrote:

>The PowerPC-specific modifiers VK_PPC_TLSGD and VK_PPC_TLSLD
>correspond exactly to the generic modifiers VK_TLSGD and VK_TLSLD.
>This causes some confusion with the asm parser, since VK_PPC_TLSGD
>is output as @tlsgd, which is then read back in as VK_TLSGD.
>
>To avoid this confusion, this patch removes the PowerPC-specific
>modifiers and uses the generic modifiers throughout.  (The only
>drawback is that the generic modifiers are printed in upper case
>while the usual convention on PowerPC is to use lower-case modifiers.
>But this is just a cosmetic issue.)

This was unfortunately incorrect, there is is fact another,
serious drawback to using the default VK_TLSLD/VK_TLSGD
variant kinds: using these causes ELFObjectWriter::RelocNeedsGOT
to return true, which in turn causes the ELFObjectWriter to emit
an undefined reference to _GLOBAL_OFFSET_TABLE_.

This is a problem on powerpc64, because it uses the TOC instead
of the GOT, and the linker does not provide _GLOBAL_OFFSET_TABLE_,
so the symbol remains undefined.  This means shared libraries
using TLS built with the integrated assembler are currently
broken.

While the whole RelocNeedsGOT / _GLOBAL_OFFSET_TABLE_ situation
probably ought to be properly fixed at some point, for now I'm
simply reverting the r185476 commit.  Now this in turn exposes
the breakage of handling @tlsgd/@tlsld in the asm parser that
this check-in was originally intended to fix.

To avoid this regression, I'm also adding a different fix for
this problem: while common code now parses @tlsgd as VK_TLSGD,
a special hack in the asm parser translates this code to the
platform-specific VK_PPC_TLSGD that the back-end now expects.
While this is not really pretty, it's self-contained and
shouldn't hurt anything else for now.  One the underlying
problem is fixed, this hack can be reverted again.

llvm-svn: 185945
2013-07-09 16:41:09 +00:00
Ulrich Weigand
cb20efc341 [PowerPC] Always use "assembler dialect" 1
A setting in MCAsmInfo defines the "assembler dialect" to use.  This is used
by common code to choose between alternatives in a multi-alternative GNU
inline asm statement like the following:

  __asm__ ("{sfe|subfe} %0,%1,%2" : "=r" (out) : "r" (in1), "r" (in2));

The meaning of these dialects is platform specific, and GCC defines those
for PowerPC to use dialect 0 for old-style (POWER) mnemonics and 1 for
new-style (PowerPC) mnemonics, like in the example above.

To be compatible with inline asm used with GCC, LLVM ought to do the same.
Specifically, this means we should always use assembler dialect 1 since
old-style mnemonics really aren't supported on any current platform.

However, the current LLVM back-end uses:
  AssemblerDialect = 1;           // New-Style mnemonics.
in PPCMCAsmInfoDarwin, and
  AssemblerDialect = 0;           // Old-Style mnemonics.
in PPCLinuxMCAsmInfo.

The Linux setting really isn't correct, we should be using new-style
mnemonics everywhere.  This is changed by this commit.

Unfortunately, the setting of this variable is overloaded in the back-end
to decide whether or not we are on a Darwin target.  This is done in
PPCInstPrinter (the "SyntaxVariant" is initialized from the MCAsmInfo
AssemblerDialect setting), and also in PPCMCExpr.  Setting AssemblerDialect
to 1 for both Darwin and Linux no longer allows us to make this distinction.

Instead, this patch uses the MCSubtargetInfo passed to createPPCMCInstPrinter
to distinguish Darwin targets, and ignores the SyntaxVariant parameter.
As to PPCMCExpr, this patch adds an explicit isDarwin argument that needs
to be passed in by the caller when creating a target MCExpr.  (To do so
this patch implicitly also reverts commit 184441.)

llvm-svn: 185858
2013-07-08 20:20:51 +00:00
Ulrich Weigand
a5490843a1 [PowerPC] Use mtocrf when available
Just as with mfocrf, it is also preferable to use mtocrf instead of
mtcrf when only a single CR register is to be written.

Current code however always emits mtcrf.  This probably does not matter
when using an external assembler, since the GNU assembler will in fact
automatically replace mtcrf with mtocrf when possible.  It does create
inefficient code with the integrated assembler, however.

To fix this, this patch adds MTOCRF/MTOCRF8 instruction patterns and
uses those instead of MTCRF/MTCRF8 everything.  Just as done in the
MFOCRF patch committed as 185556, these patterns will be converted
back to MTCRF if MTOCRF is not available on the machine.

As a side effect, this allows to modify the MTCRF pattern to accept
the full range of mask operands for the benefit of the asm parser.

llvm-svn: 185561
2013-07-03 17:59:07 +00:00
Ulrich Weigand
3a4efe4cac [PowerPC] Always use mfocrf if available
When accessing just a single CR register, it is always preferable to
use mfocrf instead of mfcr, if the former is available on the CPU.

Current code makes that distinction in many, but not all places
where a single CR register value is retrieved.  One missing
location is PPCRegisterInfo::lowerCRSpilling.

To fix this and make this simpler in the future, this patch changes
the bulk of the back-end to always assume mfocrf is available and
simply generate it when needed.

On machines that actually do not support mfocrf, the instruction
is replaced by mfcr at the very end, in EmitInstruction.

This has the additional benefit that we no longer need the
MFCRpseud hack, since before EmitInstruction we always have
a MFOCRF instruction pattern, which already models data flow
as required.

The patch also adds the MFOCRF8 version of the instruction,
which was missing so far.

Except for the PPCRegisterInfo::lowerCRSpilling case, no change
in generated code intended.

llvm-svn: 185556
2013-07-03 17:05:42 +00:00
Ulrich Weigand
b84d22f378 [PowerPC] Rework TLS call operand processing
As part of the global-dynamic and local-dynamic TLS sequences, we need
to use a special form of the call instruction:

 bl __tls_get_addr(sym@tlsld)
 bl __tls_get_addr(sym@tlsgd)

which generates two fixups.  The current implementation of this causes
problems with recognizing this form in the asm parser.  To fix this,
this patch reworks operand processing for this special form by using
a single operand to hold both __tls_get_addr and sym@tlsld and defining
a print method to output the above form, and an encoding method to
generate the two fixups.

As a side simplification, the patch replaces the two instruction
patterns BL8_NOP_TLSGD and BL8_NOP_TLSLD by a single BL8_NOP_TLS,
since the patterns already operate in an identical fashion (whether
we have a local-dynamic or global-dynamic symbol is already encoded
in the symbol modifier).

No change in code generation intended.

llvm-svn: 185477
2013-07-02 21:31:04 +00:00
Ulrich Weigand
042ff673b7 [PowerPC] Remove VK_PPC_TLSGD and VK_PPC_TLSLD
The PowerPC-specific modifiers VK_PPC_TLSGD and VK_PPC_TLSLD
correspond exactly to the generic modifiers VK_TLSGD and VK_TLSLD.
This causes some confusion with the asm parser, since VK_PPC_TLSGD
is output as @tlsgd, which is then read back in as VK_TLSGD.

To avoid this confusion, this patch removes the PowerPC-specific
modifiers and uses the generic modifiers throughout.  (The only
drawback is that the generic modifiers are printed in upper case
while the usual convention on PowerPC is to use lower-case modifiers.
But this is just a cosmetic issue.)

llvm-svn: 185476
2013-07-02 21:29:06 +00:00
Rafael Espindola
304ef43e7d Remove address spaces from MC.
This is dead code since PIC16 was removed in 2010. The result was an odd mix,
where some parts would carefully pass it along and others would assert it was
zero (most of the object streamer for example).

llvm-svn: 185436
2013-07-02 15:49:13 +00:00
Bill Schmidt
4e099704b5 Index: test/CodeGen/PowerPC/reloc-align.ll
===================================================================
--- test/CodeGen/PowerPC/reloc-align.ll	(revision 0)
+++ test/CodeGen/PowerPC/reloc-align.ll	(revision 0)
@@ -0,0 +1,34 @@
+; RUN: llc -mcpu=pwr7 -O1 < %s | FileCheck %s
+
+; This test verifies that the peephole optimization of address accesses
+; does not produce a load or store with a relocation that can't be
+; satisfied for a given instruction encoding.  Reduced from a test supplied
+; by Hal Finkel.
+
+target datalayout = "E-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-f128:128:128-v128:128:128-n32:64"
+target triple = "powerpc64-unknown-linux-gnu"
+
+%struct.S1 = type { [8 x i8] }
+
+@main.l_1554 = internal global { i8, i8, i8, i8, i8, i8, i8, i8 } { i8 -1, i8 -6, i8 57, i8 62, i8 -48, i8 0, i8 58, i8 80 }, align 1
+
+; Function Attrs: nounwind readonly
+define signext i32 @main() #0 {
+entry:
+  %call = tail call fastcc signext i32 @func_90(%struct.S1* byval bitcast ({ i8, i8, i8, i8, i8, i8, i8, i8 }* @main.l_1554 to %struct.S1*))
+; CHECK-NOT: ld {{[0-9]+}}, main.l_1554@toc@l
+  ret i32 %call
+}
+
+; Function Attrs: nounwind readonly
+define internal fastcc signext i32 @func_90(%struct.S1* byval nocapture %p_91) #0 {
+entry:
+  %0 = bitcast %struct.S1* %p_91 to i64*
+  %bf.load = load i64* %0, align 1
+  %bf.shl = shl i64 %bf.load, 26
+  %bf.ashr = ashr i64 %bf.shl, 54
+  %bf.cast = trunc i64 %bf.ashr to i32
+  ret i32 %bf.cast
+}
+
+attributes #0 = { nounwind readonly "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf"="true" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "unsafe-fp-math"="false" "use-soft-float"="false" }
Index: lib/Target/PowerPC/PPCAsmPrinter.cpp
===================================================================
--- lib/Target/PowerPC/PPCAsmPrinter.cpp	(revision 185327)
+++ lib/Target/PowerPC/PPCAsmPrinter.cpp	(working copy)
@@ -679,7 +679,26 @@ void PPCAsmPrinter::EmitInstruction(const MachineI
       OutStreamer.EmitRawText(StringRef("\tmsync"));
       return;
     }
+    break;
+  case PPC::LD:
+  case PPC::STD:
+  case PPC::LWA: {
+    // Verify alignment is legal, so we don't create relocations
+    // that can't be supported.
+    // FIXME:  This test is currently disabled for Darwin.  The test
+    // suite shows a handful of test cases that fail this check for
+    // Darwin.  Those need to be investigated before this sanity test
+    // can be enabled for those subtargets.
+    if (!Subtarget.isDarwin()) {
+      unsigned OpNum = (MI->getOpcode() == PPC::STD) ? 2 : 1;
+      const MachineOperand &MO = MI->getOperand(OpNum);
+      if (MO.isGlobal() && MO.getGlobal()->getAlignment() < 4)
+        llvm_unreachable("Global must be word-aligned for LD, STD, LWA!");
+    }
+    // Now process the instruction normally.
+    break;
   }
+  }
 
   LowerPPCMachineInstrToMCInst(MI, TmpInst, *this);
   OutStreamer.EmitInstruction(TmpInst);
Index: lib/Target/PowerPC/PPCISelDAGToDAG.cpp
===================================================================
--- lib/Target/PowerPC/PPCISelDAGToDAG.cpp	(revision 185327)
+++ lib/Target/PowerPC/PPCISelDAGToDAG.cpp	(working copy)
@@ -1530,6 +1530,14 @@ void PPCDAGToDAGISel::PostprocessISelDAG() {
       if (GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(ImmOpnd)) {
         SDLoc dl(GA);
         const GlobalValue *GV = GA->getGlobal();
+        // We can't perform this optimization for data whose alignment
+        // is insufficient for the instruction encoding.
+        if (GV->getAlignment() < 4 &&
+            (StorageOpcode == PPC::LD || StorageOpcode == PPC::STD ||
+             StorageOpcode == PPC::LWA)) {
+          DEBUG(dbgs() << "Rejected this candidate for alignment.\n\n");
+          continue;
+        }
         ImmOpnd = CurDAG->getTargetGlobalAddress(GV, dl, MVT::i64, 0, Flags);
       } else if (ConstantPoolSDNode *CP =
                  dyn_cast<ConstantPoolSDNode>(ImmOpnd)) {

llvm-svn: 185380
2013-07-01 20:52:27 +00:00
Ulrich Weigand
1b20b9f662 [PowerPC] Rename some more VK_PPC_ enums
This renames more VK_PPC_ enums, to make them more closely reflect
the @modifier string they represent.  This also prepares for adding
a bunch of new VK_PPC_ enums in upcoming patches.

For consistency, some MO_ flags related to VK_PPC_ enums are
likewise renamed.

No change in behaviour.

llvm-svn: 184547
2013-06-21 14:42:20 +00:00
Ulrich Weigand
cd7cbdb152 [PowerPC] Clean up VK_PPC_TOC... names
This is another minor cleanup; to bring enum names in line
with the corresponding @modifier names, this renames:

  VK_PPC_TOC -> VK_PPC_TOCBASE
  VK_PPC_TOC_ENTRY -> VK_PPC_TOC16

No code change intended.

llvm-svn: 184491
2013-06-20 22:39:42 +00:00
Ulrich Weigand
502b057268 [PowerPC] Remove unused parameter
The isDarwin parameter to the llvm::LowerPPCMachineInstrToMCInst
routine is now no longer needed; remove it.

llvm-svn: 184441
2013-06-20 16:58:14 +00:00
David Blaikie
813e6b3974 DebugInfo: remove target-specific Frame Index handling for DBG_VALUE MachineInstrs
Frame index handling is now target-agnostic, so delete the target hooks
for creation & asm printing of target-specific addressing in DBG_VALUEs
and any related functions.

llvm-svn: 184067
2013-06-16 20:34:27 +00:00
Ulrich Weigand
482a595fca [PowerPC] Clean up generation of ha16() / lo16() markers
When targeting the Darwin assembler, we need to generate markers ha16() and
lo16() to designate the high and low parts of a (symbolic) immediate.  This
is necessary not just for plain symbols, but also for certain symbolic
expression, typically along the lines of ha16(A - B).  The latter doesn't
work when simply using VariantKind flags on the symbol reference.
This is why the current back-end uses hacks (explicitly called out as such
via multiple FIXMEs) in the symbolLo/symbolHi print methods.

This patch uses target-defined MCExpr codes to represent the Darwin
ha16/lo16 constructs, following along the lines of the equivalent solution
used by the ARM back end to handle their :upper16: / :lower16: markers.
This allows us to get rid of special handling both in the symbolLo/symbolHi
print method and in the common code MCExpr::print routine.  Instead, the
ha16 / lo16 markers are printed simply in a custom print routine for the
target MCExpr types.  (As a result, the symbolLo/symbolHi print methods
can now replaced by a single printS16ImmOperand routine that also handles
symbolic operands.)

The patch also provides a EvaluateAsRelocatableImpl routine to handle
ha16/lo16 constructs.  This is not actually used at the moment by any
in-tree code, but is provided as it makes merging into David Fang's
out-of-tree Mach-O object writer simpler.

Since there is no longer any need to treat VK_PPC_GAS_HA16 and
VK_PPC_DARWIN_HA16 differently, they are merged into a single
VK_PPC_ADDR16_HA (and likewise for the _LO16 types).

llvm-svn: 182616
2013-05-23 22:26:41 +00:00
Peter Collingbourne
a0d11d0e11 Add support for subsections to the ELF assembler. Fixes PR8717.
Differential Revision: http://llvm-reviews.chandlerc.com/D598

llvm-svn: 179725
2013-04-17 21:18:16 +00:00
Hal Finkel
02fd9b0859 Rename the current PPC BCL definition to BCLalways
BCL is normally a conditional branch-and-link instruction, but has
an unconditional form (which is used in the SjLj code, for example).
To make clear that this BCL instruction definition is specifically
the special unconditional form (which does not meaningfully take
a condition-register input), rename it to BCLalways.

No functionality change intended.

llvm-svn: 178803
2013-04-04 22:55:54 +00:00
Ulrich Weigand
98a8d88641 PowerPC: Remove LDrs pattern.
The LDrs pattern is a duplicate of LD, except that it accepts memory
addresses where the displacement is a symbolLo64.  An operand type
"memrs" is defined for just that purpose.

However, this wouldn't be necessary if the default "memrix" operand
type were to simply accept 64-bit symbolic addresses directly.
The only problem with that is that it uses "symbolLo", which is
hardcoded to 32-bit.

To fix this, this commit changes "memri" and "memrix" to use new
operand types for the memory displacement, which allow iPTR
instead of i32.  This will also make address parsing easier to
implment in the asm parser.

No change in generated code.

llvm-svn: 178005
2013-03-26 10:55:45 +00:00
Ulrich Weigand
35b2470e07 PowerPC: Remove ADDIL patterns.
The ADDI/ADDI8 patterns are currently duplicated into ADDIL/ADDI8L,
which describe the same instruction, except that they accept a
symbolLo[64] operand instead of a s16imm[64] operand.

This duplication confuses the asm parser, and it actually not really
needed, since symbolLo[64] already accepts immediate operands anyway.
So this commit removes the duplicate patterns.

No change in generated code.

llvm-svn: 178004
2013-03-26 10:55:20 +00:00
Hal Finkel
a0112219fe MCize the bcl instruction in PPCAsmPrinter
I recently added a BCL instruction definition as part of implementing SjLj
support. This can also be used to MCize bcl emission in the asm printer.

No functionality change intended.

llvm-svn: 177830
2013-03-23 20:53:15 +00:00
Ulrich Weigand
c069500748 Remove ABI-duplicated call instruction patterns.
We currently have a duplicated set of call instruction patterns depending
on the ABI to be followed (Darwin vs. Linux).  This is a bit odd; while the
different ABIs will result in different instruction sequences, the actual
instructions themselves ought to be independent of the ABI.  And in fact it
turns out that the only nontrivial difference between the two sets of
patterns is that in the PPC64 Linux ABI, the instruction used for indirect
calls is marked to take X11 as extra input register (which is indeed used
only with that ABI to hold an incoming environment pointer for nested
functions).  However, this does not need to be hard-coded at the .td
pattern level; instead, the C++ code expanding calls can simply add that
use, just like it adds uses for argument registers anyway.

No change in generated code expected.

llvm-svn: 177735
2013-03-22 15:24:13 +00:00
Bill Schmidt
049ba390f5 Large code model support for PowerPC.
Large code model is identical to medium code model except that the
addis/addi sequence for "local" accesses is never used.  All accesses
use the addis/ld sequence.

The coding changes are straightforward; most of the patch is taken up
with creating variants of the medium model tests for large model.

llvm-svn: 175767
2013-02-21 17:12:27 +00:00
NAKAMURA Takumi
7aba9cea00 PPCDarwinAsmPrinter::EmitStartOfAsmFile(): Add checking range in CPUDirectives[].
llvm-svn: 174298
2013-02-04 00:47:38 +00:00
NAKAMURA Takumi
27b4ce56ea PPCDarwinAsmPrinter::EmitStartOfAsmFile(): Add possible elements in CPUDirectives[].
llvm-svn: 174297
2013-02-04 00:47:33 +00:00
Adhemerval Zanella
a2153405de PowerPC: EH adjustments
This patch adjust the r171506 to make all DWARF enconding pc-relative
for PPC64. It also adds the R_PPC64_REL32 relocation handling in MCJIT
(since the eh_frame will not generate PIC-relative relocation) and also
adds the emission of stubs created by the TTypeEncoding.

llvm-svn: 171979
2013-01-09 17:08:15 +00:00
Eric Christopher
38c8e00aa9 These functions have default arguments of 0 for the last arg. Use
them.

llvm-svn: 171933
2013-01-09 01:57:54 +00:00
Bill Schmidt
250d836387 This patch addresses bug 14678 by fixing two problems in medium code model
code generation.  Variables addressed through a GlobalAlias were not being
handled, and variables with available_externally linkage were treated
incorrectly.  The patch contains two new tests to verify the correct code
generation for these cases.

llvm-svn: 171778
2013-01-07 19:29:18 +00:00
Chandler Carruth
4c1f3c24db Move all of the header files which are involved in modelling the LLVM IR
into their new header subdirectory: include/llvm/IR. This matches the
directory structure of lib, and begins to correct a long standing point
of file layout clutter in LLVM.

There are still more header files to move here, but I wanted to handle
them in separate commits to make tracking what files make sense at each
layer easier.

The only really questionable files here are the target intrinsic
tablegen files. But that's a battle I'd rather not fight today.

I've updated both CMake and Makefile build systems (I think, and my
tests think, but I may have missed something).

I've also re-sorted the includes throughout the project. I'll be
committing updates to Clang, DragonEgg, and Polly momentarily.

llvm-svn: 171366
2013-01-02 11:36:10 +00:00
Bill Schmidt
c895316923 This patch improves the 64-bit PowerPC InitialExec TLS support by providing
for a wider range of GOT entries that can hold thread-relative offsets.
This matches the behavior of GCC, which was not documented in the PPC64 TLS
ABI.  The ABI will be updated with the new code sequence.

Former sequence:

  ld 9,x@got@tprel(2)
  add 9,9,x@tls

New sequence:

  addis 9,2,x@got@tprel@ha
  ld 9,x@got@tprel@l(9)
  add 9,9,x@tls

Note that a linker optimization exists to transform the new sequence into
the shorter sequence when appropriate, by replacing the addis with a nop
and modifying the base register and relocation type of the ld.

llvm-svn: 170209
2012-12-14 17:02:38 +00:00
Bill Schmidt
7a93daad1a This patch implements local-dynamic TLS model support for the 64-bit
PowerPC target.  This is the last of the four models, so we now have 
full TLS support.

This is mostly a straightforward extension of the general dynamic model.
I had to use an additional Chain operand to tie ADDIS_DTPREL_HA to the
register copy following ADDI_TLSLD_L; otherwise everything above the
ADDIS_DTPREL_HA appeared dead and was removed.

As before, there are new test cases to test the assembly generation, and
the relocations output during integrated assembly.  The expected code
gen sequence can be read in test/CodeGen/PowerPC/tls-ld.ll.

There are a couple of things I think can be done more efficiently in the
overall TLS code, so there will likely be a clean-up patch forthcoming;
but for now I want to be sure the functionality is in place.

Bill

llvm-svn: 170003
2012-12-12 19:29:35 +00:00
Bill Schmidt
45b56f7632 This patch implements the general dynamic TLS model for 64-bit PowerPC.
Given a thread-local symbol x with global-dynamic access, the generated
code to obtain x's address is:

     Instruction                            Relocation            Symbol
  addis ra,r2,x@got@tlsgd@ha           R_PPC64_GOT_TLSGD16_HA       x
  addi  r3,ra,x@got@tlsgd@l            R_PPC64_GOT_TLSGD16_L        x
  bl __tls_get_addr(x@tlsgd)           R_PPC64_TLSGD                x
                                       R_PPC64_REL24           __tls_get_addr
  nop
  <use address in r3>

The implementation borrows from the medium code model work for introducing
special forms of ADDIS and ADDI into the DAG representation.  This is made
slightly more complicated by having to introduce a call to the external
function __tls_get_addr.  Using the full call machinery is overkill and,
more importantly, makes it difficult to add a special relocation.  So I've
introduced another opcode GET_TLS_ADDR to represent the function call, and
surrounded it with register copies to set up the parameter and return value.

Most of the code is pretty straightforward.  I ran into one peculiarity
when I introduced a new PPC opcode BL8_NOP_ELF_TLSGD, which is just like
BL8_NOP_ELF except that it takes another parameter to represent the symbol
("x" above) that requires a relocation on the call.  Something in the 
TblGen machinery causes BL8_NOP_ELF and BL8_NOP_ELF_TLSGD to be treated
identically during the emit phase, so this second operand was never
visited to generate relocations.  This is the reason for the slightly
messy workaround in PPCMCCodeEmitter.cpp:getDirectBrEncoding().

Two new tests are included to demonstrate correct external assembly and
correct generation of relocations using the integrated assembler.

Comments welcome!

Thanks,
Bill

llvm-svn: 169910
2012-12-11 20:30:11 +00:00
Bill Schmidt
9d8cdcda41 This patch introduces initial-exec model support for thread-local storage
on 64-bit PowerPC ELF.

The patch includes code to handle external assembly and MC output with the
integrated assembler.  It intentionally does not support the "old" JIT.

For the initial-exec TLS model, the ABI requires the following to calculate
the address of external thread-local variable x:

 Code sequence            Relocation                  Symbol
  ld 9,x@got@tprel(2)      R_PPC64_GOT_TPREL16_DS      x
  add 9,9,x@tls            R_PPC64_TLS                 x

The register 9 is arbitrary here.  The linker will replace x@got@tprel
with the offset relative to the thread pointer to the generated GOT
entry for symbol x.  It will replace x@tls with the thread-pointer
register (13).

The two test cases verify correct assembly output and relocation output
as just described.

PowerPC-specific selection node variants are added for the two
instructions above:  LD_GOT_TPREL and ADD_TLS.  These are inserted
when an initial-exec global variable is encountered by
PPCTargetLowering::LowerGlobalTLSAddress(), and later lowered to
machine instructions LDgotTPREL and ADD8TLS.  LDgotTPREL is a pseudo
that uses the same LDrs support added for medium code model's LDtocL,
with a different relocation type.

The rest of the processing is straightforward.

llvm-svn: 169281
2012-12-04 16:18:08 +00:00
Chandler Carruth
a490793037 Use the new script to sort the includes of every file under lib.
Sooooo many of these had incorrect or strange main module includes.
I have manually inspected all of these, and fixed the main module
include to be the nearest plausible thing I could find. If you own or
care about any of these source files, I encourage you to take some time
and check that these edits were sensible. I can't have broken anything
(I strictly added headers, and reordered them, never removed), but they
may not be the headers you'd really like to identify as containing the
API being implemented.

Many forward declarations and missing includes were added to a header
files to allow them to parse cleanly when included first. The main
module rule does in fact have its merits. =]

llvm-svn: 169131
2012-12-03 16:50:05 +00:00
Bill Schmidt
0975882ed4 This patch implements medium code model support for 64-bit PowerPC.
The default for 64-bit PowerPC is small code model, in which TOC entries
must be addressable using a 16-bit offset from the TOC pointer.  Additionally,
only TOC entries are addressed via the TOC pointer.

With medium code model, TOC entries and data sections can all be addressed
via the TOC pointer using a 32-bit offset.  Cooperation with the linker
allows 16-bit offsets to be used when these are sufficient, reducing the
number of extra instructions that need to be executed.  Medium code model
also does not generate explicit TOC entries in ".section toc" for variables
that are wholly internal to the compilation unit.

Consider a load of an external 4-byte integer.  With small code model, the
compiler generates:

	ld 3, .LC1@toc(2)
	lwz 4, 0(3)

	.section	.toc,"aw",@progbits
.LC1:
	.tc ei[TC],ei

With medium model, it instead generates:

	addis 3, 2, .LC1@toc@ha
	ld 3, .LC1@toc@l(3)
	lwz 4, 0(3)

	.section	.toc,"aw",@progbits
.LC1:
	.tc ei[TC],ei

Here .LC1@toc@ha is a relocation requesting the upper 16 bits of the
32-bit offset of ei's TOC entry from the TOC base pointer.  Similarly,
.LC1@toc@l is a relocation requesting the lower 16 bits.  Note that if
the linker determines that ei's TOC entry is within a 16-bit offset of
the TOC base pointer, it will replace the "addis" with a "nop", and
replace the "ld" with the identical "ld" instruction from the small
code model example.

Consider next a load of a function-scope static integer.  For small code
model, the compiler generates:

	ld 3, .LC1@toc(2)
	lwz 4, 0(3)

	.section	.toc,"aw",@progbits
.LC1:
	.tc test_fn_static.si[TC],test_fn_static.si
	.type	test_fn_static.si,@object
	.local	test_fn_static.si
	.comm	test_fn_static.si,4,4

For medium code model, the compiler generates:

	addis 3, 2, test_fn_static.si@toc@ha
	addi 3, 3, test_fn_static.si@toc@l
	lwz 4, 0(3)

	.type	test_fn_static.si,@object
	.local	test_fn_static.si
	.comm	test_fn_static.si,4,4

Again, the linker may replace the "addis" with a "nop", calculating only
a 16-bit offset when this is sufficient.

Note that it would be more efficient for the compiler to generate:

	addis 3, 2, test_fn_static.si@toc@ha
        lwz 4, test_fn_static.si@toc@l(3)

The current patch does not perform this optimization yet.  This will be
addressed as a peephole optimization in a later patch.

For the moment, the default code model for 64-bit PowerPC will remain the
small code model.  We plan to eventually change the default to medium code
model, which matches current upstream GCC behavior.  Note that the different
code models are ABI-compatible, so code compiled with different models will
be linked and execute correctly.

I've tested the regression suite and the application/benchmark test suite in
two ways:  Once with the patch as submitted here, and once with additional
logic to force medium code model as the default.  The tests all compile
cleanly, with one exception.  The mandel-2 application test fails due to an
unrelated ABI compatibility with passing complex numbers.  It just so happens
that small code model was incredibly lucky, in that temporary values in 
floating-point registers held the expected values needed by the external
library routine that was called incorrectly.  My current thought is to correct
the ABI problems with _Complex before making medium code model the default,
to avoid introducing this "regression."

Here are a few comments on how the patch works, since the selection code
can be difficult to follow:

The existing logic for small code model defines three pseudo-instructions:
LDtoc for most uses, LDtocJTI for jump table addresses, and LDtocCPT for
constant pool addresses.  These are expanded by SelectCodeCommon().  The
pseudo-instruction approach doesn't work for medium code model, because
we need to generate two instructions when we match the same pattern.
Instead, new logic in PPCDAGToDAGISel::Select() intercepts the TOC_ENTRY
node for medium code model, and generates an ADDIStocHA followed by either
a LDtocL or an ADDItocL.  These new node types correspond naturally to
the sequences described above.

The addis/ld sequence is generated for the following cases:
 * Jump table addresses
 * Function addresses
 * External global variables
 * Tentative definitions of global variables (common linkage)

The addis/addi sequence is generated for the following cases:
 * Constant pool entries
 * File-scope static global variables
 * Function-scope static variables

Expanding to the two-instruction sequences at select time exposes the
instructions to subsequent optimization, particularly scheduling.

The rest of the processing occurs at assembly time, in
PPCAsmPrinter::EmitInstruction.  Each of the instructions is converted to
a "real" PowerPC instruction.  When a TOC entry needs to be created, this
is done here in the same manner as for the existing LDtoc, LDtocJTI, and
LDtocCPT pseudo-instructions (I factored out a new routine to handle this).

I had originally thought that if a TOC entry was needed for LDtocL or
ADDItocL, it would already have been generated for the previous ADDIStocHA.
However, at higher optimization levels, the ADDIStocHA may appear in a 
different block, which may be assembled textually following the block
containing the LDtocL or ADDItocL.  So it is necessary to include the
possibility of creating a new TOC entry for those two instructions.

Note that for LDtocL, we generate a new form of LD called LDrs.  This
allows specifying the @toc@l relocation for the offset field of the LD
instruction (i.e., the offset is replaced by a SymbolLo relocation).
When the peephole optimization described above is added, we will need
to do similar things for all immediate-form load and store operations.

The seven "mcm-n.ll" test cases are kept separate because otherwise the
intermingling of various TOC entries and so forth makes the tests fragile
and hard to understand.

The above assumes use of an external assembler.  For use of the
integrated assembler, new relocations are added and used by
PPCELFObjectWriter.  Testing is done with "mcm-obj.ll", which tests for
proper generation of the various relocations for the same sequences
tested with the external assembler.

llvm-svn: 168708
2012-11-27 17:35:46 +00:00
Benjamin Kramer
2cd9913ab9 Decouple MCInstBuilder from the streamer per Eli's request.
llvm-svn: 168597
2012-11-26 18:05:52 +00:00
Benjamin Kramer
8f414c9010 Add MCInstBuilder, a utility class to simplify MCInst creation similar to MachineInstrBuilder.
Simplify some repetitive code with it. No functionality change.

llvm-svn: 168587
2012-11-26 13:34:22 +00:00
Benjamin Kramer
42c6896fe3 PPC: MCize most of the darwin PIC emission.
The last remaining bit is "bcl 20, 31, AnonSymbol", which I couldn't find the
instruction definition for. Only whitespace changes in assembly output.

llvm-svn: 168541
2012-11-24 13:18:25 +00:00
Benjamin Kramer
3b83fc3c6b PPC: Simplify code with Twines.
No functionality change.

llvm-svn: 168539
2012-11-24 13:18:11 +00:00
Ulrich Weigand
497a8eab4a Make TOC order deterministic by using MapVector instead of DenseMap.
llvm-svn: 167737
2012-11-12 19:13:24 +00:00
Hal Finkel
a82b79fc22 Add support for the PowerPC-specific inline asm Z constraint and y modifier.
The Z constraint specifies an r+r memory address, and the y modifier expands
to the "r, r" in the asm string. For this initial implementation, the base
register is forced to r0 (which has the special meaning of 0 for r+r addressing
on PowerPC) and the full address is taken in the second register. In the
future, this should be improved.

llvm-svn: 167388
2012-11-05 18:18:42 +00:00
Chandler Carruth
0a6b99ee2b Revert the majority of the next patch in the address space series:
r165941: Resubmit the changes to llvm core to update the functions to
         support different pointer sizes on a per address space basis.

Despite this commit log, this change primarily changed stuff outside of
VMCore, and those changes do not carry any tests for correctness (or
even plausibility), and we have consistently found questionable or flat
out incorrect cases in these changes. Most of them are probably correct,
but we need to devise a system that makes it more clear when we have
handled the address space concerns correctly, and ideally each pass that
gets updated would receive an accompanying test case that exercises that
pass specificaly w.r.t. alternate address spaces.

However, from this commit, I have retained the new C API entry points.
Those were an orthogonal change that probably should have been split
apart, but they seem entirely good.

In several places the changes were very obvious cleanups with no actual
multiple address space code added; these I have not reverted when
I spotted them.

In a few other places there were merge conflicts due to a cleaner
solution being implemented later, often not using address spaces at all.
In those cases, I've preserved the new code which isn't address space
dependent.

This is part of my ongoing effort to clean out the partial address space
code which carries high risk and low test coverage, and not likely to be
finished before the 3.2 release looms closer. Duncan and I would both
like to see the above issues addressed before we return to these
changes.

llvm-svn: 167222
2012-11-01 09:14:31 +00:00
Adhemerval Zanella
b08709a59f Initial TOC support for PowerPC64 object creation
This patch adds initial PPC64 TOC MC object creation using the small mcmodel
(a single 64K TOC) adding the some TOC relocations (R_PPC64_TOC,
R_PPC64_TOC16, and R_PPC64_TOC16DS).

The addition of 'undefinedExplicitRelSym' hook on 'MCELFObjectTargetWriter'
is meant to avoid the creation of an unreferenced ".TOC." symbol (used in
the .odp creation) as well to set the R_PPC64_TOC relocation target as the
temporary ".TOC." symbol. On PPC64 ABI, the R_PPC64_TOC relocation should
not point to any symbol.

llvm-svn: 166677
2012-10-25 12:27:42 +00:00
Micah Villmow
272663afc2 Resubmit the changes to llvm core to update the functions to support different pointer sizes on a per address space basis.
llvm-svn: 165941
2012-10-15 16:24:29 +00:00
Adhemerval Zanella
ad392b0f93 PowerPC: add EmitTCEntry class for TOC creation
This patch replaces the EmitRawText by a EmitTCEntry class (specialized for
each Streamer) in PowerPC64 TOC entry creation.

llvm-svn: 165940
2012-10-15 15:43:14 +00:00
Micah Villmow
4eb108750d Revert 165732 for further review.
llvm-svn: 165747
2012-10-11 21:27:41 +00:00
Micah Villmow
d8b76fdc50 Add in the first iteration of support for llvm/clang/lldb to allow variable per address space pointer sizes to be optimized correctly.
llvm-svn: 165726
2012-10-11 17:21:41 +00:00
Micah Villmow
bb1a25cd67 Move TargetData to DataLayout.
llvm-svn: 165402
2012-10-08 16:38:25 +00:00
Roman Divacky
bb7740900c Avoid symbol name clash when filling TOC.
Patch by Adhemerval Zanella.

llvm-svn: 164141
2012-09-18 17:10:37 +00:00
Roman Divacky
377f342a56 On PPC64 emit the environment pointer. Patch by Adhemerval Zanella.
llvm-svn: 164139
2012-09-18 16:55:29 +00:00
Roman Divacky
1a4b67cd3a Remove always true checks. Noticed by Adhemerval Zanella.
llvm-svn: 163117
2012-09-03 16:55:42 +00:00
Hal Finkel
b356af14b1 Reserve space for the mandatory traceback fields on PPC64.
We need to reserve space for the mandatory traceback fields,
though leaving them as zero is appropriate for now.

Although the ABI calls for these fields to be filled in fully, no
compiler on Linux currently does this, and GDB does not read these
fields.  GDB uses the first word of zeroes during exception handling to
find the end of the function and the size field, allowing it to compute
the beginning of the function.  DWARF information is used for everything
else.  We need the extra 8 bytes of pad so the size field is found in
the right place.

As a comparison, GCC fills in a few of the fields -- language, number
of saved registers -- but ignores the rest.  IBM's proprietary OSes do
make use of the full traceback table facility.

Patch by Bill Schmidt.

llvm-svn: 162854
2012-08-29 20:22:24 +00:00