[PATCH] D86393: [GISel] Add combines for unary FP instrs with constant operand

[Matt Arsenault via Phabricator via llvm-commits]

arsenm added inline comments.


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Comment at: llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp:1486-1489
+  if (DstTy == S16)
+    V.convert(APFloat::IEEEhalf(), APFloat::rmNearestTiesToEven, &Unused);
+  else if (DstTy == S32)
+    V.convert(APFloat::IEEEsingle(), APFloat::rmNearestTiesToEven, &Unused);
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mkitzan wrote:
> arsenm wrote:
> > We should probably have a getFltSemanticForLLT utility somewhere for this
> Doesn't appear to be one for `LLT`. I suspect because unlike `Type`, with its discrete number of `TypeID`s, `LLT` is very open ended.
Yes, that's why there should be one. An FP LLT isn't any arbitrary number of bits, there's still only the handful of valid FP type combinations. We're probably going to have to add something to track f16 vs. bf16, but for now it's still a switch over a handful of valid FP sizes


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  https://reviews.llvm.org/D86393/new/

https://reviews.llvm.org/D86393