From 527dd604302e13f96132e9f045745d6eec8c8d37 Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Sat, 6 Dec 2008 22:49:05 +0000 Subject: [PATCH] add a note llvm-svn: 60632 --- llvm/lib/Target/X86/README.txt | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/llvm/lib/Target/X86/README.txt b/llvm/lib/Target/X86/README.txt index c02eca6410fb..eb110fe60f6b 100644 --- a/llvm/lib/Target/X86/README.txt +++ b/llvm/lib/Target/X86/README.txt @@ -1816,3 +1816,18 @@ like the following: A similar code sequence works for division. //===---------------------------------------------------------------------===// + +These should compile to the same code, but the later codegen's to useless +instructions on X86. This may be a trivial dag combine (GCC PR7061): + +struct s1 { unsigned char a, b; }; +unsigned long f1(struct s1 x) { + return x.a + x.b; +} +struct s2 { unsigned a: 8, b: 8; }; +unsigned long f2(struct s2 x) { + return x.a + x.b; +} + +//===---------------------------------------------------------------------===// +