[PATCH] D55481: [CostModel][X86] Have getArithmeticReductionCost call back to the target code after the loop reaches a legal type. Only handle legal/simple types from the X86 code

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon added inline comments.


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Comment at: include/llvm/CodeGen/BasicTTIImpl.h:1426
         LT.second.isVector() ? LT.second.getVectorNumElements() : 1;
-    while (NumVecElts > MVTLen) {
-      NumVecElts /= 2;
-      Ty = VectorType::get(ScalarTy, NumVecElts);
+    if (NumVecElts > MVTLen) {
+      do {
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Please add a comment describing how this is supposed to work (similar to the patch's summary).


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D55481/new/

https://reviews.llvm.org/D55481