[LLParser] Reader vector GEP ConsantExpr correctly

[mkuper]

Summary

The CE version was too constrained - it seems like it was not relaxed enough when vector GEPs were introduces.
This relaxes the checks to be similar to the ones for the instruction version.

This fixes PR30816.

[delena]

lib/AsmParser/LLParser.cpp

3213

else

GEPWidth = ValNumEl;

If you add these 2 lines, you check that all indices have the same vector width.

[mkuper]

lib/AsmParser/LLParser.cpp

3213

Right, missed this (and, of course, I didn't add a negative test... serves me right.)
Thanks!

[mkuper]

Added missing check.

lib/AsmParser/LLParser.cpp

if (Opc == Instruction::GetElementPtr) {
 
       Type *BaseType = Elts[0]->getType();
       auto *BasePointerType = cast<PointerType>(BaseType->getScalarType());
       if (Ty != BasePointerType->getElementType())
         return Error(
             ExplicitTypeLoc,
             "explicit pointee type doesn't match operand's pointee type");
 
+      unsigned GEPWidth =
+          BaseType->isVectorTy() ? BaseType->getVectorNumElements() : 0;
+
       ArrayRef<Constant *> Indices(Elts.begin() + 1, Elts.end());
       for (Constant *Val : Indices) {
         Type *ValTy = Val->getType();
         if (!ValTy->getScalarType()->isIntegerTy())
           return Error(ID.Loc, "getelementptr index must be an integer");
-        if (ValTy->isVectorTy() != BaseType->isVectorTy())
-          return Error(ID.Loc, "getelementptr index type missmatch");
         if (ValTy->isVectorTy()) {
           unsigned ValNumEl = ValTy->getVectorNumElements();
-          unsigned PtrNumEl = BaseType->getVectorNumElements();
-          if (ValNumEl != PtrNumEl)
+          if (GEPWidth && (ValNumEl != GEPWidth))
             return Error(
                 ID.Loc,
                 "getelementptr vector index has a wrong number of elements");
+          // GEPWidth may have been unknown because the base is a scalar,
+          // but it is known now.
+          GEPWidth = ValNumEl;
         }
       }
 
       SmallPtrSet<Type*, 4> Visited;
       if (!Indices.empty() && !Ty->isSized(&Visited))
         return Error(ID.Loc, "base element of getelementptr must be sized");
 
       if (!GetElementPtrInst::getIndexedType(Ty, Indices))
         return Error(ID.Loc, "invalid getelementptr indices");

test/Assembler/getelementptr_vec_ce.ll

+; RUN: llvm-as < %s | llvm-dis | FileCheck %s
+
+@G = global [4 x i32] zeroinitializer
+
+; CHECK-LABEL: @foo
+; CHECK: ret <4 x i32*> getelementptr ([4 x i32], [4 x i32]* @G, <4 x i32> zeroinitializer, <4 x i32> <i32 0, i32 1, i32 2, i32 3>)
+define <4 x i32*> @foo() {
+  ret <4 x i32*> getelementptr ([4 x i32], [4 x i32]* @G, i32 0, <4 x i32> <i32 0, i32 1, i32 2, i32 3>)
+}

test/Assembler/getelementptr_vec_ce2.ll

+; RUN: not llvm-as < %s 2>&1 | FileCheck %s
+
+@G = global [4 x [4 x i32]] zeroinitializer
+
+; CHECK: getelementptr vector index has a wrong number of elements
+define <4 x i32*> @foo() {
+  ret <4 x i32*> getelementptr ([4 x [4 x i32]], [4 x [4 x i32]]* @G, i32 0, <4 x i32> <i32 0, i32 1, i32 2, i32 3>, <8 x i32> zeroinitializer)
+}