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(parent: b859d6d) | patch
X86: Improve BT instruction selection for 64-bit values.
authorPeter Collingbourne <peter@pcc.me.uk>
Fri, 21 Oct 2016 19:57:55 +0000 (19:57 +0000)
committerPeter Collingbourne <peter@pcc.me.uk>
Fri, 21 Oct 2016 19:57:55 +0000 (19:57 +0000)
commit7d77c5caa7216c96c68a6c4f1042b1b5c01e1ae2
tree945b752f8e360f0332b690444ac28f146b2c3058tree | snapshot
parentb859d6d852eb5355d6fed6fda27c6270f99301f7commit | diff
X86: Improve BT instruction selection for 64-bit values.

If a 64-bit value is tested against a bit which is known to be in the range
[0..31) (modulo 64), we can use the 32-bit BT instruction, which has a slightly
shorter encoding.

Differential Revision: https://reviews.llvm.org/D25862

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284864 91177308-0d34-0410-b5e6-96231b3b80d8
lib/Target/X86/X86ISelLowering.cpp diff | blob | history
test/CodeGen/X86/bt.ll diff | blob | history
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