[llvm] [LV] Stop using the legacy cost model for udiv + friends (PR #152707)

[David Sherwood via llvm-commits]

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@@ -952,6 +952,19 @@ InstructionCost VPInstruction::computeCost(ElementCount VF,
   }
 
   switch (getOpcode()) {
+  case Instruction::Select: {
+    // TODO: It may be possible to improve this by analyzing where the
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david-arm wrote:

Ah ok thanks. I'll take a look at what you did in #154468! For what it's worth I ran the LLVM test suite for a number of configs on AArch64 and I didn't see any assertions, but it seems like @fhahn did so I'm just waiting for the new tests.

https://github.com/llvm/llvm-project/pull/152707