Differential D19708

powerpc64: Use medium code model in asm files for TOC references
ClosedPublic
Actions

Authored by jhibbits on Mar 26 2019, 3:46 AM.

Details

Reviewers

nwhitehorn
luporl

Commits

rS348691: MFC r345676:
rS345676: powerpc64: Use medium code model in asm files for TOC references

Summary

With a sufficiently large TOC, it's possible to index out of range, as
the immediate load instructions only permit 16-bit indices, allowing up
to 64kB range (signed) from the base pointer. Allow +/- 2GB range, with
the medium code model TOC accesses in asm.

Patch originally by Brandon Bergren. The issue appears to impact ELFv2
more than ELFv1.

Diff Detail

Lint

Lint Passed

Unit

No Test Coverage

Build Status

Buildable 23300
Build 22331: arc lint + arc unit

Event Timeline

jhibbits created this revision.Mar 26 2019, 3:46 AM

Harbormaster completed remote builds in B23300: Diff 55447.Mar 26 2019, 3:46 AM

LGTM.
I see this is basically a subset of D19352, with the exception of booke/locore.S, right?
BTW, I need to come back to D19352 and refactor it.

This revision is now accepted and ready to land.Mar 26 2019, 2:00 PM

Correct. It didn't logically belong with D19352, and probably other chunks of D19352 can be broken out, too, into more consumable pieces. The booke part I added for completness/consistency sake.