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[X86] Disable the NOP padding for branches when bundle is enabled
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Authored by skan on Feb 28 2020, 5:32 AM.

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Summary

When bundle is enabled, data fragment itself has a space to emit NOP to bundle-align instructions. The behaviour makes it impossible for us to determine whether the macro fusion really happen when emitting instructions. In addition, boundary-align fragment is also used to emit NOPs to align instructions, currently using them together sometimes makes code crazy.

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Event Timeline

skan created this revision.Feb 28 2020, 5:32 AM
Herald added a project: Restricted Project. · View Herald TranscriptFeb 28 2020, 5:32 AM
reames accepted this revision.Feb 28 2020, 1:51 PM

LGTM

This revision is now accepted and ready to land.Feb 28 2020, 1:51 PM
jyknight accepted this revision.Feb 28 2020, 2:47 PM

(Still worth considering removing the bundle_align feature entirely, but in the meantime, definitely good to not blow up).

MaskRay accepted this revision.Feb 28 2020, 3:39 PM

(+1 considering removal of .bundle_align_mode)

This revision was automatically updated to reflect the committed changes.