fix a bozo bug I introduced in r119930, causing a miscompile of

20040709-1.c from the gcc testsuite.  I was using the size of a
pointer instead of the pointee.  This fixes rdar://8713376

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120519 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Scalar/MemCpyOptimizer.cpp b/lib/Transforms/Scalar/MemCpyOptimizer.cpp
index 087f022fe9d209f11a8a76bc838d4762104e55e4..5d867e71547d198a90443ea757a90a56a4e5ec09 100644 (file)
--- a/lib/Transforms/Scalar/MemCpyOptimizer.cpp
+++ b/lib/Transforms/Scalar/MemCpyOptimizer.cpp
@@ -814,7 +814,8 @@ bool MemCpyOpt::processByValArgument(CallSite CS, unsigned ArgNo) {
 
   // Find out what feeds this byval argument.
   Value *ByValArg = CS.getArgument(ArgNo);
-  uint64_t ByValSize = TD->getTypeAllocSize(ByValArg->getType());
+  const Type *ByValTy =cast<PointerType>(ByValArg->getType())->getElementType();
+  uint64_t ByValSize = TD->getTypeAllocSize(ByValTy);
   MemDepResult DepInfo =
     MD->getPointerDependencyFrom(AliasAnalysis::Location(ByValArg, ByValSize),
                                  true, CS.getInstruction(),

diff --git a/test/Transforms/MemCpyOpt/memcpy.ll b/test/Transforms/MemCpyOpt/memcpy.ll
index 7309319c46eb1bf16845122c2e710b61292d3a44..16b80a628a3c1dbbe070f61cecfb55c4490f10d5 100644 (file)
--- a/test/Transforms/MemCpyOpt/memcpy.ll
+++ b/test/Transforms/MemCpyOpt/memcpy.ll
@@ -77,3 +77,26 @@ define void @test4(i8 *%P) {
 
 declare void @test4a(i8* byval align 1)
 declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture, i64, i32, i1) nounwind
+
+%struct.S = type { i128, [4 x i8]}
+
+@sS = external global %struct.S, align 16
+
+declare void @test5a(%struct.S* byval align 16) nounwind ssp
+
+declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture, i64, i32, i1) nounwind
+
+; rdar://8713376 - This memcpy can't be eliminated.
+define i32 @test5(i32 %x) nounwind ssp {
+entry:
+  %y = alloca %struct.S, align 16
+  %tmp = bitcast %struct.S* %y to i8*
+  call void @llvm.memcpy.p0i8.p0i8.i64(i8* %tmp, i8* bitcast (%struct.S* @sS to i8*), i64 32, i32 16, i1 false)
+  %a = getelementptr %struct.S* %y, i64 0, i32 1, i64 0
+  store i8 4, i8* %a
+  call void @test5a(%struct.S* byval align 16 %y)
+  ret i32 0
+  ; CHECK: @test5(
+  ; CHECK: store i8 4
+  ; CHECK: call void @test5a(%struct.S* byval align 16 %y)
+}