diff options
Diffstat (limited to 'test/Transforms/InstCombine/malloc-free-delete.ll')
| -rw-r--r-- | test/Transforms/InstCombine/malloc-free-delete.ll | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/test/Transforms/InstCombine/malloc-free-delete.ll b/test/Transforms/InstCombine/malloc-free-delete.ll index 4e3217dc2d..cd12b29b11 100644 --- a/test/Transforms/InstCombine/malloc-free-delete.ll +++ b/test/Transforms/InstCombine/malloc-free-delete.ll @@ -91,3 +91,32 @@ define void @test5(i8* %ptr, i8** %esc) { store volatile i8 4, i8* %g ret void } + +;; When a basic block contains only a call to free and this block is accessed +;; through a test of the argument of free against null, move the call in the +;; predecessor block. +;; Using simplifycfg will remove the empty basic block and the branch operation +;; Then, performing a dead elimination will remove the comparison. +;; This is what happens with -O1 and upper. +; CHECK: @test6 +define void @test6(i8* %foo) minsize { +; CHECK: %tobool = icmp eq i8* %foo, null +;; Call to free moved +; CHECK-NEXT: tail call void @free(i8* %foo) +; CHECK-NEXT: br i1 %tobool, label %if.end, label %if.then +; CHECK: if.then: +;; Block is now empty and may be simplified by simplifycfg +; CHECK-NEXT: br label %if.end +; CHECK: if.end: +; CHECK-NEXT: ret void +entry: + %tobool = icmp eq i8* %foo, null + br i1 %tobool, label %if.end, label %if.then + +if.then: ; preds = %entry + tail call void @free(i8* %foo) + br label %if.end + +if.end: ; preds = %entry, %if.then + ret void +} |