diff options
author | Benjamin Kramer <benny.kra@googlemail.com> | 2012-03-02 15:34:43 +0000 |
---|---|---|
committer | Benjamin Kramer <benny.kra@googlemail.com> | 2012-03-02 15:34:43 +0000 |
commit | 8979e5f3725c05bd7120890e39399213fd08f83e (patch) | |
tree | 8fd22ad3d8f049fb32881a8103e5707c037c0dce /test/Transforms/CorrelatedValuePropagation | |
parent | 0c7374d87e6bf002028cd19f8ae9547927c9c645 (diff) | |
download | llvm-8979e5f3725c05bd7120890e39399213fd08f83e.tar.gz llvm-8979e5f3725c05bd7120890e39399213fd08f83e.tar.bz2 llvm-8979e5f3725c05bd7120890e39399213fd08f83e.tar.xz |
LVI: Recognize the form instcombine canonicalizes range checks into when forming constant ranges.
This could probably be made a lot smarter, but this is a common case and doesn't require LVI to scan a lot
of code. With this change CVP can optimize away the "shift == 0" case in Hashing.h that only gets hit when
"shift" is in a range not containing 0.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151919 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test/Transforms/CorrelatedValuePropagation')
-rw-r--r-- | test/Transforms/CorrelatedValuePropagation/range.ll | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/test/Transforms/CorrelatedValuePropagation/range.ll b/test/Transforms/CorrelatedValuePropagation/range.ll new file mode 100644 index 0000000000..9b70ed200e --- /dev/null +++ b/test/Transforms/CorrelatedValuePropagation/range.ll @@ -0,0 +1,43 @@ +; RUN: opt -correlated-propagation -S < %s | FileCheck %s + +declare i32 @foo() + +define i32 @test1(i32 %a) nounwind { + %a.off = add i32 %a, -8 + %cmp = icmp ult i32 %a.off, 8 + br i1 %cmp, label %then, label %else + +then: + %dead = icmp eq i32 %a, 7 + br i1 %dead, label %end, label %else + +else: + ret i32 1 + +end: + ret i32 2 + +; CHECK: @test1 +; CHECK: then: +; CHECK-NEXT: br i1 false, label %end, label %else +} + +define i32 @test2(i32 %a) nounwind { + %a.off = add i32 %a, -8 + %cmp = icmp ult i32 %a.off, 8 + br i1 %cmp, label %then, label %else + +then: + %dead = icmp ugt i32 %a, 15 + br i1 %dead, label %end, label %else + +else: + ret i32 1 + +end: + ret i32 2 + +; CHECK: @test2 +; CHECK: then: +; CHECK-NEXT: br i1 false, label %end, label %else +} |