[PATCH] D111523: [AMDGPU] Don't emit 24 bit mul intrinsic for > 32 bit result.

[Jay Foad via Phabricator via llvm-commits]

foad added a comment.

In D111523#3055898 <https://reviews.llvm.org/D111523#3055898>, @rampitec wrote:

> There should be nothing wrong with mul24 regardless of the destination type. If a 64 bit mul fits 24 bit it still can use 24 bit mul, just extended to 64 bit.

No, I think this patch makes sense. We were only checking that the inputs fit in 24 bits. A full 24-bit multiply would have a 48 bit result, which you could safely extend to 64 bits. But mul24 gives you a truncated 32-bit result, which you can't safely extend to 64 bits.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D111523/new/

https://reviews.llvm.org/D111523