[rocjitsu] Fix gfx1250 flat private scratch decoding#7781
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atgutier
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Jun 24, 2026
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LGMT, but some comments that may need to be addressed.
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Motivation
Fix gfx1250 flat private scratch address decoding.
Technical Details
LLVM lowers private-to-flat scratch addresses using gfx1250 lane bits in the flat scratch address encoding. We were treating those addresses as ordinary global addresses, so nonzero lanes read from the wrong backing location and the HIP repro returned incorrect values.
Add gfx1250 flat private address translation that strips the encoded lane bits and maps the private offset into RocJITsu’s per-lane scratch backing layout, with a regression test covering the lane-bit decoding path.
JIRA ID
N/A
Test Plan
Unit tests + repro in https://gist.github.com/lua1235/62fa1506c584b454e3135406eea75c42 + fpsan suite.
No generator changes.
Test Result
All good.
Submission Checklist