From 275b8846d519ac91777e6cad00b8650b252d2ed6 Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Thu, 2 Feb 2006 07:37:11 +0000 Subject: [PATCH] new example git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25903 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Target/PowerPC/README.txt | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/lib/Target/PowerPC/README.txt b/lib/Target/PowerPC/README.txt index d77d20d85ad..468d974a278 100644 --- a/lib/Target/PowerPC/README.txt +++ b/lib/Target/PowerPC/README.txt @@ -448,3 +448,22 @@ LBB1_2: blr noticed in 2005-05-11-Popcount-ffs-fls.c. + + +===-------------------------------------------------------------------------=== + +We should custom expand setcc instead of pretending that we have it. That +would allow us to expose the access of the crbit after the mfcr, allowing +that access to be trivially folded into other ops. A simple example: + +int foo(int a, int b) { return (a < b) << 4; } + +compiles into: + +_foo: + cmpw cr7, r3, r4 + mfcr r2, 1 + rlwinm r2, r2, 29, 31, 31 + slwi r3, r2, 4 + blr +