From d52998a8155e2c45d131e2dbfb97c3fdcbb57435 Mon Sep 17 00:00:00 2001 From: Benjamin Kramer Date: Sat, 23 Jun 2012 15:19:31 +0000 Subject: [PATCH] Add a microoptimization note. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159082 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Target/README.txt | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/lib/Target/README.txt b/lib/Target/README.txt index 093255e6af2..cbfa4cf35ba 100644 --- a/lib/Target/README.txt +++ b/lib/Target/README.txt @@ -964,6 +964,12 @@ optimized with "clang -emit-llvm-bc | opt -std-compile-opts". //===---------------------------------------------------------------------===// +unsigned f(unsigned x) { return ((x & 7) + 1) & 15; } +The & 15 part should be optimized away, it doesn't change the result. Currently +not optimized with "clang -emit-llvm-bc | opt -std-compile-opts". + +//===---------------------------------------------------------------------===// + This was noticed in the entryblock for grokdeclarator in 403.gcc: %tmp = icmp eq i32 %decl_context, 4