teach instcombine to remove allocated buffers even if there are stores, memcpy/memmove/memset, and objectsize users.
This means we can do cheap DSE for heap memory.
Nothing is done if the pointer excapes or has a load.
The churn in the tests is mostly due to objectsize, since we want to make sure we
don't delete the malloc call before evaluating the objectsize (otherwise it becomes -1/0)
llvm-svn: 159876
diff --git a/llvm/test/Transforms/InstCombine/badmalloc.ll b/llvm/test/Transforms/InstCombine/badmalloc.ll
index f5a623d..3abe28a 100644
--- a/llvm/test/Transforms/InstCombine/badmalloc.ll
+++ b/llvm/test/Transforms/InstCombine/badmalloc.ll
@@ -16,5 +16,26 @@
ret i1 %B
; CHECK: @test1
-; CHECK: ret i1 %B
+; CHECK: ret i1 false
+}
+
+; CHECK: @test2
+define noalias i8* @test2() nounwind {
+entry:
+; CHECK: @malloc
+ %A = call noalias i8* @malloc(i64 4) nounwind
+; CHECK: icmp eq
+ %tobool = icmp eq i8* %A, null
+; CHECK: br i1
+ br i1 %tobool, label %return, label %if.end
+
+if.end:
+; CHECK: store
+ store i8 7, i8* %A
+ br label %return
+
+return:
+; CHECK: phi
+ %retval.0 = phi i8* [ %A, %if.end ], [ null, %entry ]
+ ret i8* %retval.0
}