[flang] [llvm] [VPlan] Expand WidenInt inductions with nuw/nsw (PR #163538)

[Ramkumar Ramachandra via llvm-commits]

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@@ -122,6 +122,22 @@ std::optional<VPValue *>
 getRecipesForUncountableExit(VPlan &Plan,
                              SmallVectorImpl<VPRecipeBase *> &Recipes,
                              SmallVectorImpl<VPRecipeBase *> &GEPs);
+
+/// Extracts and returns nowrap flags from the induction binop in \p ID. \p
+/// DropNWFlags tells us whether whether we should drop NoWrap flags, which we
+/// should when tail-folding, for example.
+inline VPIRFlags getNoWrapFlagsFromIndDesc(const InductionDescriptor &ID,
+                                           bool DropNWFlags) {
+  if (ID.getKind() == InductionDescriptor::IK_FpInduction)
+    return ID.getInductionBinOp()->getFastMathFlags();
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artagnon wrote:

This behavior hasn't changed with the patch. Not sure why we need to drop FMF for tail-folded loops?

https://github.com/llvm/llvm-project/pull/163538