Make sure scalarrepl picks the correct alloca when it rewrites a bitcast. Fixes PR11353.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144442 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Eli Friedman 2011-11-12 02:07:50 +00:00
parent d1ac3a47f2
commit 75f69e3a3d
2 changed files with 36 additions and 2 deletions

View File

@ -1875,8 +1875,14 @@ void SROA::RewriteBitCast(BitCastInst *BC, AllocaInst *AI, uint64_t Offset,
return;
// The bitcast references the original alloca. Replace its uses with
// references to the first new element alloca.
Instruction *Val = NewElts[0];
// references to the alloca containing offset zero (which is normally at
// index zero, but might not be in cases involving structs with elements
// of size zero).
Type *T = AI->getAllocatedType();
uint64_t EltOffset = 0;
Type *IdxTy;
uint64_t Idx = FindElementAndOffset(T, EltOffset, IdxTy);
Instruction *Val = NewElts[Idx];
if (Val->getType() != BC->getDestTy()) {
Val = new BitCastInst(Val, BC->getDestTy(), "", BC);
Val->takeName(BC);
@ -2160,6 +2166,8 @@ void SROA::RewriteMemIntrinUserOfAlloca(MemIntrinsic *MI, Instruction *Inst,
}
unsigned EltSize = TD->getTypeAllocSize(EltTy);
if (!EltSize)
continue;
IRBuilder<> Builder(MI);

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@ -0,0 +1,26 @@
; RUN: opt < %s -S -scalarrepl | 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-S128"
%struct.S = type { [2 x %struct.anon], double }
%struct.anon = type {}
; CHECK: @test()
; CHECK-NOT: alloca
; CHECK: ret double 1.0
define double @test() nounwind uwtable ssp {
entry:
%retval = alloca %struct.S, align 8
%ret = alloca %struct.S, align 8
%b = getelementptr inbounds %struct.S* %ret, i32 0, i32 1
store double 1.000000e+00, double* %b, align 8
%0 = bitcast %struct.S* %retval to i8*
%1 = bitcast %struct.S* %ret to i8*
call void @llvm.memcpy.p0i8.p0i8.i64(i8* %0, i8* %1, i64 8, i32 8, i1 false)
%2 = bitcast %struct.S* %retval to double*
%3 = load double* %2, align 1
ret double %3
}
declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture, i64, i32, i1) nounwind