[PATCH] D157111: AMDGPU: Try to select fmul by power of 2 to ldexp

[Jay Foad via Phabricator via llvm-commits]

foad added inline comments.


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Comment at: llvm/lib/Target/AMDGPU/SIInstructions.td:3334
+    // [+-]4.0, [+-]2.0, [+-]0.5, [+-]1.0
+    if (Exp >= -2 && Exp <= 2)
+      return false;
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Should be `>= -1`. As is you are treating +/-0.25 as an inline.


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Comment at: llvm/test/CodeGen/AMDGPU/GlobalISel/inst-select-fmul.mir:277
+
+...
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Need some tests with negated powers of two. I don't see how the patch handles these.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D157111/new/

https://reviews.llvm.org/D157111