From 2d09c00b918c29cf3e581459eed1946987357722 Mon Sep 17 00:00:00 2001 From: James Molloy Date: Thu, 12 Nov 2015 12:39:41 +0000 Subject: [InstCombine] Add trivial folding (bitreverse (bitreverse x)) -> x There are plenty more instcombines we could probably do with bitreverse, but this seems like a very obvious and trivial starting point and was brought up by Hal in his review. llvm-svn: 252879 --- llvm/test/Transforms/InstCombine/bitreverse-fold.ll | 11 +++++++++++ 1 file changed, 11 insertions(+) create mode 100644 llvm/test/Transforms/InstCombine/bitreverse-fold.ll (limited to 'llvm/test/Transforms') diff --git a/llvm/test/Transforms/InstCombine/bitreverse-fold.ll b/llvm/test/Transforms/InstCombine/bitreverse-fold.ll new file mode 100644 index 00000000000..ad7fc3a7464 --- /dev/null +++ b/llvm/test/Transforms/InstCombine/bitreverse-fold.ll @@ -0,0 +1,11 @@ +; RUN: opt < %s -instcombine -S | FileCheck %s + +define i32 @test1(i32 %p) { +; CHECK-LABEL: @test1 +; CHECK-NEXT: ret i32 %p + %a = call i32 @llvm.bitreverse.i32(i32 %p) + %b = call i32 @llvm.bitreverse.i32(i32 %a) + ret i32 %b +} + +declare i32 @llvm.bitreverse.i32(i32) readnone -- cgit v1.2.3