[InstCombine] Optimize (select %x, op(%x), 0) to op(%x) for operations where op(0) == 0 #147605

Merged

bababuck merged 9 commits intollvm:mainfrom

bababuck:bababuck/SelectFixed0

Jul 17, 2025

Commits on Jul 15, 2025

Add tests for cases with (select %x, op(%x), 0) for operations where op(0) == 0

Ryan Buchner
authored and
bababuck
committed
[InstCombine] Optimize (select %x, op(%x), 0) to op(%x) for operations where op(0) == 0

Ryan Buchner
authored and
bababuck
committed
Reorder so that matching occurs before any data extraction
bababuck
committed
Use m_c_Intrinsic<Intrinisic::umin> instead of m_c_UMin
bababuck
committed
Don't match with `shl`, `ashr`, and `ashl` because if the `shfamt` is too large we can create a `poison` value
bababuck
committed
Don't match with `udiv` and `sdiv` because if the denominator is 0 we can create `undef` value
bababuck
committed
Add back in SDiv/UDiv/URem/SRem, but don't freeze them
bababuck
committed
Match to m_I[Div/Rem] rather than the individual signed and unsigned versions

bababuck
and
dtcxzyw
committed
Add tests for commuted versions of AND and MUL
bababuck
committed