[llvm] [VPlan] Also expand pointer-typed SCEVAddExpr in VPSCEVExpander. (PR #206366)

[Ramkumar Ramachandra via llvm-commits]

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@@ -846,9 +846,25 @@ VPValue *VPSCEVExpander::tryToExpand(const SCEV *S) {
     return Builder.createNaryOp(VPInstruction::VScale, {}, S->getType());
   case scAddExpr:
   case scMulExpr: {
-    if (S->getType()->isPointerTy())
-      return nullptr;
     auto *NAry = cast<SCEVNAryExpr>(S);
+    VPIRFlags::WrapFlagsTy WrapFlags(NAry->hasNoUnsignedWrap(),
+                                     NAry->hasNoSignedWrap());
+
+    // Expanded poiner SCEVAddExpr as a ptradd of the pointer base and the
+    // integer offset, matching SCEVExpander.
+    if (S->getType()->isPointerTy()) {
+      VPValue *Base = tryToExpand(SE.getPointerBase(S));
+      if (!Base)
+        return nullptr;
+      VPValue *Offset = tryToExpand(SE.removePointerBase(S));
+      if (!Offset)
+        return nullptr;
+      GEPNoWrapFlags GEPFlags = WrapFlags.HasNUW
+                                    ? GEPNoWrapFlags::noUnsignedWrap()
+                                    : GEPNoWrapFlags::none();
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artagnon wrote:

What about the nusw case? Also, why are we dropping self-wrap: does it not translate?

https://github.com/llvm/llvm-project/pull/206366