RPCS3/llvm-mirror
1
0
Fork 0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-10-21 12:02:58 +02:00
Code Issues Projects Releases Wiki Activity

Improve the safety of my globalopt enhancement by ensuring that the bitcast

Browse Source 
of the stored value to the new store type is always.  Also, add a testcase.

llvm-svn: 123563
This commit is contained in:
Owen Anderson 2011-01-16 04:33:33 +00:00
parent aba06ce448
commit 6e0fa67f91
2 changed files with 81 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

34
lib/Transforms/IPO/GlobalOpt.cpp
View File

@ -2358,21 +2358,31 @@ static bool EvaluateFunction(Function *F, Constant *&RetVal,
const Type *NewTy=cast<PointerType>(Ptr->getType())->getElementType();
// A bitcast'd pointer implicitly points to the first field of a
// struct. Insert implicity "gep @x, 0, 0, ..." until we get down
// to the first concrete member.
// FIXME: This could be extended to work for arrays as well.
while (const StructType *STy = dyn_cast<StructType>(NewTy)) {
NewTy = STy->getTypeAtIndex(0U);
// In order to push the bitcast onto the stored value, a bitcast
// from NewTy to Val's type must be legal. If it's not, we can try
// introspecting NewTy to find a legal conversion.
while (!Val->getType()->canLosslesslyBitCastTo(NewTy)) {
// If NewTy is a struct, we can convert the pointer to the struct
// into a pointer to its first member.
// FIXME: This could be extended to support arrays as well.
if (const StructType *STy = dyn_cast<StructType>(NewTy)) {
NewTy = STy->getTypeAtIndex(0U);
const IntegerType *IdxTy =IntegerType::get(NewTy->getContext(), 32);
Constant *IdxZero = ConstantInt::get(IdxTy, 0, false);
Constant * const IdxList[] = {IdxZero, IdxZero};
Ptr = ConstantExpr::getGetElementPtr(Ptr, IdxList, 2);
const IntegerType *IdxTy =IntegerType::get(NewTy->getContext(), 32);
Constant *IdxZero = ConstantInt::get(IdxTy, 0, false);
Constant * const IdxList[] = {IdxZero, IdxZero};
Ptr = ConstantExpr::getGetElementPtr(Ptr, IdxList, 2);
// If we can't improve the situation by introspecting NewTy,
// we have to give up.
} else {
return 0;
}
}
if (!isa<PointerType>(NewTy)) return false;
// If we found compatible types, go ahead and push the bitcast
// onto the stored value.
Val = ConstantExpr::getBitCast(Val, NewTy);
}

59
test/Transforms/GlobalOpt/static-ctor-bitcast.ll Normal file
View File

@ -0,0 +1,59 @@
; RUN: opt -S -globalopt < %s | FileCheck %s
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-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
target triple = "x86_64-apple-darwin10.0.0"
%0 = type { i8*, i8* }
%1 = type { i8*, i8*, i32, i32, i8*, i64 }
%2 = type { i32, void ()* }
%struct.A = type { i32 }
%struct.B = type { i32 (...)**, i8*, [4 x i8] }
@y = global i8 0, align 1
@x = global %struct.B zeroinitializer, align 8
@_ZTV1B = weak_odr unnamed_addr constant [3 x i8*] [i8* inttoptr (i64 16 to i8*), i8* null, i8* bitcast (%1* @_ZTI1B to i8*)]
@_ZTVN10__cxxabiv121__vmi_class_type_infoE = external global i8*
@_ZTS1B = weak_odr constant [3 x i8] c"1B\00"
@_ZTVN10__cxxabiv117__class_type_infoE = external global i8*
@_ZTS1A = weak_odr constant [3 x i8] c"1A\00"
@_ZTI1A = weak_odr unnamed_addr constant %0 { i8* bitcast (i8** getelementptr inbounds (i8** @_ZTVN10__cxxabiv117__class_type_infoE, i64 2) to i8*), i8* getelementptr inbounds ([3 x i8]* @_ZTS1A, i32 0, i32 0) }
@_ZTI1B = weak_odr unnamed_addr constant %1 { i8* bitcast (i8** getelementptr inbounds (i8** @_ZTVN10__cxxabiv121__vmi_class_type_infoE, i64 2) to i8*), i8* getelementptr inbounds ([3 x i8]* @_ZTS1B, i32 0, i32 0), i32 0, i32 1, i8* bitcast (%0* @_ZTI1A to i8*), i64 -6141 }
@_ZTT1B = weak_odr unnamed_addr constant [1 x i8*] [i8* bitcast (i8** getelementptr inbounds ([3 x i8*]* @_ZTV1B, i64 1, i64 0) to i8*)]
@llvm.global_ctors = appending global [1 x %2] [%2 { i32 65535, void ()* @_GLOBAL__I_a }]
; CHECK-NOT: __cxx_global_var_init
define internal void @__cxx_global_var_init() section "__TEXT,__StaticInit,regular,pure_instructions" {
entry:
call void @_ZN1BC1Ev(%struct.B* @x)
ret void
}
; CHECK-NOT: _ZN1BC1Ev
define linkonce_odr unnamed_addr void @_ZN1BC1Ev(%struct.B* %this) inlinehint ssp align 2 {
entry:
%0 = bitcast %struct.B* %this to i8*
%1 = getelementptr inbounds i8* %0, i64 16
%2 = bitcast i8* %1 to %struct.A*
call void @_ZN1AC2Ev(%struct.A* %2)
%3 = bitcast %struct.B* %this to i8***
store i8** getelementptr inbounds ([3 x i8*]* @_ZTV1B, i64 1, i64 0), i8*** %3
ret void
}
; CHECK-NOT: _ZN1AC2Ev
define linkonce_odr unnamed_addr void @_ZN1AC2Ev(%struct.A* %this) nounwind ssp align 2 {
entry:
%0 = ptrtoint %struct.A* %this to i64
%sub = sub i64 %0, ptrtoint (%struct.B* @x to i64)
%div = udiv i64 %sub, 8
%conv = trunc i64 %div to i8
store i8 %conv, i8* @y, align 1
ret void
}
; CHECK-NOT: _GLOBAL__I_a
define internal void @_GLOBAL__I_a() section "__TEXT,__StaticInit,regular,pure_instructions" {
entry:
call void @__cxx_global_var_init()
ret void
}