[MemCpyOpt] Look at any dependency -not just source- for memset+memcpy.
This fixes another miscompile introduced by r235232: when there was a
dependency on the memcpy destination other than the memset, we would
ignore it, because we only looked at the source dependency.
It was a mistake to use SrcDepInfo. Instead, just use DepInfo.
llvm-svn: 237066
diff --git a/llvm/test/Transforms/MemCpyOpt/memset-memcpy-redundant-memset.ll b/llvm/test/Transforms/MemCpyOpt/memset-memcpy-redundant-memset.ll
index 0a21e71..d0ec1dd 100644
--- a/llvm/test/Transforms/MemCpyOpt/memset-memcpy-redundant-memset.ll
+++ b/llvm/test/Transforms/MemCpyOpt/memset-memcpy-redundant-memset.ll
@@ -126,6 +126,24 @@
ret void
}
+; Make sure we also take into account dependencies on the destination.
+
+; CHECK-LABEL: define i8 @test_intermediate_read
+; CHECK-NEXT: %ca = alloca [64 x i8], align 8
+; CHECK-NEXT: %c = getelementptr [64 x i8], [64 x i8]* %ca, i64 0, i64 0
+; CHECK-NEXT: call void @llvm.memset.p0i8.i64(i8* %a, i8 0, i64 64, i32 1, i1 false)
+; CHECK-NEXT: %r = load i8, i8* %a
+; CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i64(i8* %a, i8* %b, i64 24, i32 1, i1 false)
+; CHECK-NEXT: ret i8 %r
+define i8 @test_intermediate_read(i8* %a, i8* %b) #0 {
+ %ca = alloca [64 x i8], align 8
+ %c = getelementptr [64 x i8], [64 x i8]* %ca, i64 0, i64 0
+ call void @llvm.memset.p0i8.i64(i8* %a, i8 0, i64 64, i32 1, i1 false)
+ %r = load i8, i8* %a
+ call void @llvm.memcpy.p0i8.p0i8.i64(i8* %a, i8* %b, i64 24, i32 1, i1 false)
+ ret i8 %r
+}
+
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)