From 92a87c67eeac09cbc8ad7ad69a9fe1be99d570b7 Mon Sep 17 00:00:00 2001 From: Hal Finkel Date: Mon, 5 Jan 2015 21:41:26 +0000 Subject: [PATCH] [PowerPC] Remove README.txt entry This entry has been rendered irrelevant now that we have proper CR bit tracking. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225211 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Target/PowerPC/README.txt | 34 ---------------------------------- 1 file changed, 34 deletions(-) diff --git a/lib/Target/PowerPC/README.txt b/lib/Target/PowerPC/README.txt index 9565ae131f8..29238fd2a55 100644 --- a/lib/Target/PowerPC/README.txt +++ b/lib/Target/PowerPC/README.txt @@ -184,40 +184,6 @@ just fastcc. ===-------------------------------------------------------------------------=== -Compile this: - -int foo(int a) { - int b = (a < 8); - if (b) { - return b * 3; // ignore the fact that this is always 3. - } else { - return 2; - } -} - -into something not this: - -_foo: -1) cmpwi cr7, r3, 8 - mfcr r2, 1 - rlwinm r2, r2, 29, 31, 31 -1) cmpwi cr0, r3, 7 - bgt cr0, LBB1_2 ; UnifiedReturnBlock -LBB1_1: ; then - rlwinm r2, r2, 0, 31, 31 - mulli r3, r2, 3 - blr -LBB1_2: ; UnifiedReturnBlock - li r3, 2 - blr - -In particular, the two compares (marked 1) could be shared by reversing one. -This could be done in the dag combiner, by swapping a BR_CC when a SETCC of the -same operands (but backwards) exists. In this case, this wouldn't save us -anything though, because the compares still wouldn't be shared. - -===-------------------------------------------------------------------------=== - Fold add and sub with constant into non-extern, non-weak addresses so this: static int a;