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[ARM] Add command-line option for SB
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Authored by dnsampaio on Dec 21 2018, 2:07 AM.

Details

Summary

SB (Speculative Barrier) is only mandatory from 8.5
onwards but is optional from Armv8.0-A. This patch adds a command
line option to enable SB, as it was previously only possible to
enable by selecting -march=armv8.5-a.

This patch also renames FeatureSpecRestrict to FeatureSB.

Similar patch upstream in GNU binutils:
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=commit;h=7fadb25d6faf2665305016ceb4aeaeeb86015569

and GCC
https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=2e148a35710c1890a185a1d4cdb79848b2727eae

Diff Detail

Repository
rL LLVM

Event Timeline

dnsampaio created this revision.Dec 21 2018, 2:07 AM
olista01 added inline comments.
lib/Target/ARM/ARM.td
371 ↗(On Diff #179251)

Same comment as the AArch64 patch (D55921), FeatureSpecCtrl already contains only the SB instruction.

dnsampaio updated this revision to Diff 179264.Dec 21 2018, 4:00 AM
dnsampaio marked an inline comment as done.
dnsampaio edited the summary of this revision. (Show Details)

Remove empty feature. Rename a few more test files to have sb instead of specRest.

LukeCheeseman accepted this revision.Dec 28 2018, 8:53 AM
This revision is now accepted and ready to land.Dec 28 2018, 8:53 AM
This revision was automatically updated to reflect the committed changes.