v8/test/unittests/compiler/arm64
Pierre Langlois 77021584fe [arm64] Generate TBNZ for 32-bit '(x & (1 << N)) == (1 << N)'
Add support for matching '(x & mask) == mask' when mask has a single bit set,
and translate this into a tbnz instruction. This patch only does this for 32-bit
operations, we can port it to 64-bit operations as a follow-up if we find
matches.

This transformation mostly touches the snapshot where we get ~120 hits. This pattern can
also show up in JavaScript when introduced by the EffectControlLinearizer pass.

Bug: 
Change-Id: Ib37c6e0bd3831b7c17709357b00ca53735621605
Reviewed-on: https://chromium-review.googlesource.com/803272
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Pierre Langlois <pierre.langlois@arm.com>
Cr-Commit-Position: refs/heads/master@{#49822}
2017-12-04 10:23:25 +00:00
..
instruction-selector-arm64-unittest.cc [arm64] Generate TBNZ for 32-bit '(x & (1 << N)) == (1 << N)' 2017-12-04 10:23:25 +00:00