[X86] Fold XOR of two vgf2p8affineqb instructions with same input (#179900)
This patch implements an optimization to fold XOR of two
`vgf2p8affineqb` instructions operating on the same input.
This optimization:
Reduces instruction count from 3 to 2
Eliminates one vgf2p8affineqb instruction
Added combineXorWithTwoGF2P8AFFINEQB function in X86ISelLowering.cpp
Uses sd_match pattern matching for consistency with existing code
Checks that both operations have single use to avoid code bloat
Verifies both operations use the same input
Handles commutative XOR patterns automatically
[analyzer] Fix crash in MallocChecker when a function has both ownership_returns and ownership_takes (#183583)
When a function was annotated with both `ownership_returns` and
`ownership_takes` (or `ownership_holds`), MallocChecker::evalCall would
fall into the freeing-only branch (isFreeingOwnershipAttrCall) and call
checkOwnershipAttr without first calling MallocBindRetVal. That meant no
heap symbol had been conjured for the return value, so
checkOwnershipAttr later dereferenced a null/invalid symbol and crashed.
Fix: merge the two dispatch branches so that MallocBindRetVal is always
called first whenever ownership_returns is present, regardless of
whether the function also carries ownership_takes/ownership_holds.
The crash was introduced in #106081
339282d49f5310a2837da45c0ccc19da15675554.
Released in clang-20, and crashing ever since.
Fixes #183344.
Assisted-By: claude
