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| author | Dan Gohman <gohman@apple.com> | 2011-01-21 22:07:57 +0000 |
|---|---|---|
| committer | Dan Gohman <gohman@apple.com> | 2011-01-21 22:07:57 +0000 |
| commit | 8fb25c53bdc22a1f480ac0a6c0215a23f397deb3 (patch) | |
| tree | b2cdfd68bc01d2252d2b6b0f9fa03ec2825ffafe | |
| parent | fc3faa75cbadd8a1020941ec85adfda1d2f49688 (diff) | |
Actually check memcpy lengths, instead of just commenting about
how they should be checked.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123999 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | lib/Transforms/Scalar/MemCpyOptimizer.cpp | 6 | ||||
| -rw-r--r-- | test/Transforms/MemCpyOpt/smaller.ll | 28 |
2 files changed, 32 insertions, 2 deletions
diff --git a/lib/Transforms/Scalar/MemCpyOptimizer.cpp b/lib/Transforms/Scalar/MemCpyOptimizer.cpp index 0d3c5c7bdc..acddf0878b 100644 --- a/lib/Transforms/Scalar/MemCpyOptimizer.cpp +++ b/lib/Transforms/Scalar/MemCpyOptimizer.cpp @@ -690,8 +690,10 @@ bool MemCpyOpt::processMemCpyMemCpyDependence(MemCpyInst *M, MemCpyInst *MDep, // Second, the length of the memcpy's must be the same, or the preceeding one // must be larger than the following one. - ConstantInt *C1 = dyn_cast<ConstantInt>(MDep->getLength()); - if (!C1) return false; + ConstantInt *MDepLen = dyn_cast<ConstantInt>(MDep->getLength()); + ConstantInt *MLen = dyn_cast<ConstantInt>(M->getLength()); + if (!MDepLen || !MLen || MDepLen->getZExtValue() < MLen->getZExtValue()) + return false; AliasAnalysis &AA = getAnalysis<AliasAnalysis>(); diff --git a/test/Transforms/MemCpyOpt/smaller.ll b/test/Transforms/MemCpyOpt/smaller.ll new file mode 100644 index 0000000000..1d35582d99 --- /dev/null +++ b/test/Transforms/MemCpyOpt/smaller.ll @@ -0,0 +1,28 @@ +; RUN: opt -memcpyopt -S < %s | FileCheck %s +; rdar://8875553 + +; Memcpyopt shouldn't optimize the second memcpy using the first +; because the first has a smaller size. + +; CHECK: call void @llvm.memcpy.p0i8.p0i8.i32(i8* %tmp, i8* getelementptr inbounds (%struct.s* @cell, i32 0, i32 0, i32 0), i32 16, i32 4, i1 false) + +target datalayout = "e-p:32:32:32" + +%struct.s = type { [11 x i8], i32 } + +@.str = private constant [11 x i8] c"0123456789\00" +@cell = external global %struct.s + +declare void @check(%struct.s* byval %p) nounwind +declare void @llvm.memcpy.p0i8.p0i8.i32(i8* nocapture, i8* nocapture, i32, i32, i1) nounwind + +define void @foo() nounwind { +entry: + %agg.tmp = alloca %struct.s, align 4 + store i32 99, i32* getelementptr inbounds (%struct.s* @cell, i32 0, i32 1), align 4 + call void @llvm.memcpy.p0i8.p0i8.i32(i8* getelementptr inbounds (%struct.s* @cell, i32 0, i32 0, i32 0), i8* getelementptr inbounds ([11 x i8]* @.str, i32 0, i32 0), i32 11, i32 1, i1 false) + %tmp = getelementptr inbounds %struct.s* %agg.tmp, i32 0, i32 0, i32 0 + call void @llvm.memcpy.p0i8.p0i8.i32(i8* %tmp, i8* getelementptr inbounds (%struct.s* @cell, i32 0, i32 0, i32 0), i32 16, i32 4, i1 false) + call void @check(%struct.s* byval %agg.tmp) + ret void +} |