[PATCH] D110890: [GlobalISel] Port the udiv -> mul by constant combine.

[Amara Emerson via Phabricator via llvm-commits]

aemerson added a comment.

@arsenm @foad The `udiv.i64.ll` test has had an abort line put it because this patch causes a G_MULH of <2 x s64> to be generated which is currently not legalized for AMDGPU.



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Comment at: llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp:4429
+/// of the divided value are known zero.
+static mu magicu(const APInt &d, unsigned LeadingZeros = 0) {
+  unsigned p;
----------------
This function currently copied but can be shared with the DAG, but I'm waiting for D98200 to land so we can put it in a common utils file.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D110890/new/

https://reviews.llvm.org/D110890