Commit Graph

7 Commits

Author SHA1 Message Date
Michael Kuperstein 3e3652aef2 Recommit r274692 - [X86] Transform setcc + movzbl into xorl + setcc
xorl + setcc is generally the preferred sequence due to the partial register
stall setcc + movzbl suffers from. As a bonus, it also encodes one byte smaller.
This fixes PR28146.

The original commit tried inserting an 8bit-subreg into a GR32 (not GR32_ABCD)
which was not appreciated by fast regalloc on 32-bit.

llvm-svn: 274802
2016-07-07 22:50:23 +00:00
Michael Kuperstein edb38a94f8 Revert r274692 to check whether this is what breaks windows selfhost.
llvm-svn: 274771
2016-07-07 16:55:35 +00:00
Michael Kuperstein 1ef6c59b1d [X86] Transform setcc + movzbl into xorl + setcc
xorl + setcc is generally the preferred sequence due to the partial register
stall setcc + movzbl suffers from. As a bonus, it also encodes one byte smaller.

This fixes PR28146.

Differential Revision: http://reviews.llvm.org/D21774

llvm-svn: 274692
2016-07-06 21:56:18 +00:00
Bill Wendling 410ec4aad1 As Dan pointed out, movzbl, movsbl, and friends are nicer than their alias
(movzx/movsx) because they give more information. Revert that part of the patch.

llvm-svn: 129498
2011-04-14 01:46:37 +00:00
Bill Wendling 7e07d6fb69 Have the X86 back-end emit the alias instead of what's being aliased. In most
cases, it's much nicer and more informative reading the alias.

llvm-svn: 129497
2011-04-14 01:11:51 +00:00
Dan Gohman 40503396da Eliminate more uses of llvm-as and llvm-dis.
llvm-svn: 81290
2009-09-08 23:54:48 +00:00
Evan Cheng ab35bfdf18 Fix a (u)comiss intrinsic lowering bug. It was using anyext which can return junk in higher bits. Patch by Nate Begeman.
llvm-svn: 54903
2008-08-17 19:22:34 +00:00