diff options
Diffstat (limited to 'test/Transforms/MemCpyOpt/callslot_deref.ll')
| -rw-r--r-- | test/Transforms/MemCpyOpt/callslot_deref.ll | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/test/Transforms/MemCpyOpt/callslot_deref.ll b/test/Transforms/MemCpyOpt/callslot_deref.ll new file mode 100644 index 0000000..4d51552 --- /dev/null +++ b/test/Transforms/MemCpyOpt/callslot_deref.ll @@ -0,0 +1,29 @@ +; RUN: opt < %s -S -basicaa -memcpyopt | FileCheck %s +target datalayout = "e-i64:64-f80:128-n8:16:32:64-S128" + +declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture readonly, i64, i32, i1) unnamed_addr nounwind +declare void @llvm.memset.p0i8.i64(i8* nocapture, i8, i64, i32, i1) nounwind + +; all bytes of %dst that are touch by the memset are dereferenceable +define void @must_remove_memcpy(i8* noalias nocapture dereferenceable(4096) %dst) { +; CHECK-LABEL: @must_remove_memcpy( +; CHECK: call void @llvm.memset.p0i8.i64 +; CHECK-NOT: call void @llvm.memcpy.p0i8.p0i8.i64 + %src = alloca [4096 x i8], align 1 + %p = getelementptr inbounds [4096 x i8]* %src, i64 0, i64 0 + call void @llvm.memset.p0i8.i64(i8* %p, i8 0, i64 4096, i32 1, i1 false) + call void @llvm.memcpy.p0i8.p0i8.i64(i8* %dst, i8* %p, i64 4096, i32 1, i1 false) #2 + ret void +} + +; memset touch more bytes than those guaranteed to be dereferenceable +define void @must_not_remove_memcpy(i8* noalias nocapture dereferenceable(1024) %dst) { +; CHECK-LABEL: @must_not_remove_memcpy( +; CHECK: call void @llvm.memset.p0i8.i64 +; CHECK: call void @llvm.memcpy.p0i8.p0i8.i64 + %src = alloca [4096 x i8], align 1 + %p = getelementptr inbounds [4096 x i8]* %src, i64 0, i64 0 + call void @llvm.memset.p0i8.i64(i8* %p, i8 0, i64 4096, i32 1, i1 false) + call void @llvm.memcpy.p0i8.p0i8.i64(i8* %dst, i8* %p, i64 4096, i32 1, i1 false) #2 + ret void +} |