[PATCH] D84592: [X86] Add custom lowering for llvm.roundeven with sse4.1.

[Craig Topper via Phabricator via llvm-commits]

craig.topper added inline comments.


================
Comment at: llvm/lib/Target/X86/X86ISelDAGToDAG.cpp:1026
+      case ISD::STRICT_FROUNDEVEN:
+      case ISD::FROUNDEVEN: Imm = 0x8; break;
       case ISD::STRICT_FNEARBYINT:
----------------
sepavloff wrote:
> Should it be 0?
> From ROUNDSS description:
> ```
> Precision (signaled only if imm[3] = ‘0; if imm[3] = ‘1, then the Precision Mask in the MXSCSR is ignored and precision
> exception is not signaled.)
> ```
> Should it be 0?
> From ROUNDSS description:
> ```
> Precision (signaled only if imm[3] = ‘0; if imm[3] = ‘1, then the Precision Mask in the MXSCSR is ignored and precision
> exception is not signaled.)
> ```

I thought TS 18661-1 doesn't allow roundeven/round/ceil/trunc/floor to raise inexact exception.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D84592/new/

https://reviews.llvm.org/D84592