[llvm] [TLI] Fix replace-with-veclib crash with invalid arguments (PR #77112)

[Maciej Gabka via llvm-commits]

================
@@ -170,30 +170,31 @@ static bool replaceWithCallToVeclib(const TargetLibraryInfo &TLI,
   if (!OptInfo)
     return false;
 
-  FunctionType *VectorFTy = VFABI::createFunctionType(*OptInfo, ScalarFTy);
-  if (!VectorFTy)
-    return false;
-
-  Function *TLIFunc = getTLIFunction(I.getModule(), VectorFTy,
-                                     VD->getVectorFnName(), FuncToReplace);
-
-  // For calls, bail out when their arguments do not match with the TLI mapping.
+  // There is no guarantee that the vectorized instructions followed the VFABI
+  // specification when being created, this is why we need to add extra check to
+  // make sure that the operands of the vector function obtained via VFABI match
+  // the operands of the original vector instruction.
   if (CI) {
-    int IdxNonPred = 0;
-    for (auto [OrigTy, VFParam] :
-         zip(OrigArgTypes, OptInfo->Shape.Parameters)) {
+    for (auto VFParam : OptInfo->Shape.Parameters) {
       if (VFParam.ParamKind == VFParamKind::GlobalPredicate)
         continue;
-      ++IdxNonPred;
+      Type *OrigTy = OrigArgTypes[VFParam.ParamPos];
----------------
mgabka wrote:

nit: to avoid confusion, I think it is worth to add an assert to check if the VFParam.ParamPos < OrigArgTypes.size() with a comment that this is guaranteed by the tryDemangleForVFABI, is if it failed most likely there is a bug in the VFABI parser.

https://github.com/llvm/llvm-project/pull/77112