InstCombine: If we call llvm.objectsize on a malloc call we can replace it with the size passed to malloc.

llvm-svn: 122959

1 files changed, 16 insertions, 0 deletions

diff --git a/llvm/test/Transforms/InstCombine/objsize.ll b/llvm/test/Transforms/InstCombine/objsize.ll
index 043525b7555..9950e5f4cc6 100644
--- a/llvm/test/Transforms/InstCombine/objsize.ll
+++ b/llvm/test/Transforms/InstCombine/objsize.ll
@@ -160,3 +160,19 @@ define i32 @test7() {
   ret i32 %objsize
 }
 
+define i32 @test8(i32 %x) {
+; CHECK: @test8
+  %alloc = call noalias i8* @malloc(i32 %x) nounwind
+  %objsize = call i32 @llvm.objectsize.i32(i8* %alloc, i1 false) nounwind readonly
+; CHECK-NEXT: ret i32 %x
+  ret i32 %objsize
+}
+
+define i32 @test9(i32 %x) {
+; CHECK: @test9
+  %alloc = call noalias i8* @malloc(i32 %x) nounwind
+  %gep = getelementptr inbounds i8* %alloc, i32 16
+  %objsize = call i32 @llvm.objectsize.i32(i8* %gep, i1 false) nounwind readonly
+; CHECK-NOT: ret i32 %x
+  ret i32 %objsize
+}