diff options
Diffstat (limited to 'llvm')
| -rw-r--r-- | llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp | 9 | ||||
| -rw-r--r-- | llvm/test/Transforms/MemCpyOpt/memset-memcpy-redundant-memset.ll | 22 |
2 files changed, 29 insertions, 2 deletions
diff --git a/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp b/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp index a90204d26bd..66d6ac6f3a0 100644 --- a/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp +++ b/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp @@ -859,6 +859,13 @@ bool MemCpyOpt::processMemSetMemCpyDependence(MemCpyInst *MemCpy, if (MemSet->getDest() != MemCpy->getDest()) return false; + // Check that there are no other dependencies on the memset destination. + MemDepResult DstDepInfo = + MD->getPointerDependencyFrom(AliasAnalysis::getLocationForDest(MemSet), + false, MemCpy, MemCpy->getParent()); + if (DstDepInfo.getInst() != MemSet) + return false; + // Use the same i8* dest as the memcpy, killing the memset dest if different. Value *Dest = MemCpy->getRawDest(); Value *DestSize = MemSet->getLength(); @@ -874,7 +881,7 @@ bool MemCpyOpt::processMemSetMemCpyDependence(MemCpyInst *MemCpy, if (ConstantInt *SrcSizeC = dyn_cast<ConstantInt>(SrcSize)) Align = MinAlign(SrcSizeC->getZExtValue(), DestAlign); - IRBuilder<> Builder(MemSet); + IRBuilder<> Builder(MemCpy); // If the sizes have different types, zext the smaller one. if (DestSize->getType() != SrcSize->getType()) { diff --git a/llvm/test/Transforms/MemCpyOpt/memset-memcpy-redundant-memset.ll b/llvm/test/Transforms/MemCpyOpt/memset-memcpy-redundant-memset.ll index 25411f26982..993c8a1bb2d 100644 --- a/llvm/test/Transforms/MemCpyOpt/memset-memcpy-redundant-memset.ll +++ b/llvm/test/Transforms/MemCpyOpt/memset-memcpy-redundant-memset.ll @@ -1,4 +1,4 @@ -; RUN: opt -memcpyopt -S %s | FileCheck %s +; RUN: opt -basicaa -memcpyopt -S %s | FileCheck %s target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128" @@ -140,6 +140,26 @@ define i8 @test_intermediate_read(i8* %a, i8* %b) #0 { ret i8 %r } +%struct = type { [8 x i8], [8 x i8] } + +; CHECK-LABEL: define void @test_intermediate_write +; CHECK-NEXT: %a = alloca %struct +; CHECK-NEXT: %a0 = getelementptr %struct, %struct* %a, i32 0, i32 0, i32 0 +; CHECK-NEXT: %a1 = getelementptr %struct, %struct* %a, i32 0, i32 1, i32 0 +; CHECK-NEXT: call void @llvm.memset.p0i8.i64(i8* %a0, i8 0, i64 16, i32 1, i1 false) +; CHECK-NEXT: store i8 1, i8* %a1 +; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i64(i8* %a0, i8* %b, i64 8, i32 1, i1 false) +; CHECK-NEXT: ret void +define void @test_intermediate_write(i8* %b) #0 { + %a = alloca %struct + %a0 = getelementptr %struct, %struct* %a, i32 0, i32 0, i32 0 + %a1 = getelementptr %struct, %struct* %a, i32 0, i32 1, i32 0 + call void @llvm.memset.p0i8.i64(i8* %a0, i8 0, i64 16, i32 1, i1 false) + store i8 1, i8* %a1 + call void @llvm.memcpy.p0i8.p0i8.i64(i8* %a0, i8* %b, i64 8, i32 1, i1 false) + ret void +} + declare void @llvm.memset.p0i8.i64(i8* nocapture, i8, i64, i32, i1) declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture readonly, i64, i32, i1) declare void @llvm.memset.p0i8.i32(i8* nocapture, i8, i32, i32, i1) |
