[PATCH] D102673: [ConstantFolding] Fold constrained arithmetic intrinsics

[Sanjay Patel via Phabricator via llvm-commits]

spatel added a reviewer: scanon.
spatel added a subscriber: scanon.
spatel added a comment.

Ping @scanon to comment on whether the exception vs. fold-ability logic seems correct.



================
Comment at: llvm/lib/Analysis/ConstantFolding.cpp:1910-1911
+  RoundingMode RM = RoundingMode::Dynamic;
+  Optional<RoundingMode> ORM = CI->getRoundingMode();
+  if (ORM)
+    RM = *ORM;
----------------
I think this would be easier to read if we made it more like the code above here:

```
  Optional<RoundingMode> ORM = CI->getRoundingMode();
  // If no rounding mode is specified by the intrinsic or the mode is dynamic,
  // try to evaluate using the default mode. If it does not raise an inexact
  // exception, rounding was not applied so the result is independent of
  // rounding mode. 
  if (!ORM || *ORM == RoundingMode::Dynamic) 
    return RoundingMode::NearestTiesToEven;
  // Use the mode specified by the intrinsic.
  return *ORM;
```
That's assuming I'm reading it correctly right now - are there tests with no RM specified on the intrinsic?


Repository:
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https://reviews.llvm.org/D102673