Extended syntax of vector version of getelementptr instruction.

The justification of this change is here: http://lists.cs.uiuc.edu/pipermail/llvmdev/2015-March/082989.html

According to the current GEP syntax, vector GEP requires that each index must be a vector with the same number of elements.

%A = getelementptr i8, <4 x i8*> %ptrs, <4 x i64> %offsets

In this implementation I let each index be or vector or scalar. All vector indices must have the same number of elements. The scalar value will mean the splat vector value.

(1) %A = getelementptr i8, i8* %ptr, <4 x i64> %offsets
or
(2) %A = getelementptr i8, <4 x i8*> %ptrs, i64 %offset

In all cases the %A type is <4 x i8*>

In the case (2) we add the same offset to all pointers.

The case (1) covers C[B[i]] case, when we have the same base C and different offsets B[i].

The documentation is updated.

http://reviews.llvm.org/D10496

llvm-svn: 241788

1 files changed, 11 insertions, 7 deletions

diff --git a/llvm/lib/AsmParser/LLParser.cpp b/llvm/lib/AsmParser/LLParser.cpp
index b3c7fa087d4..91a88bc91fd 100644
--- a/llvm/lib/AsmParser/LLParser.cpp
+++ b/llvm/lib/AsmParser/LLParser.cpp
@@ -2873,8 +2873,8 @@ bool LLParser::ParseValID(ValID &ID, PerFunctionState *PFS) {
         if (ValTy->isVectorTy() != BaseType->isVectorTy())
           return Error(ID.Loc, "getelementptr index type missmatch");
         if (ValTy->isVectorTy()) {
-          unsigned ValNumEl = cast<VectorType>(ValTy)->getNumElements();
-          unsigned PtrNumEl = cast<VectorType>(BaseType)->getNumElements();
+          unsigned ValNumEl = ValTy->getVectorNumElements();
+          unsigned PtrNumEl = BaseType->getVectorNumElements();
           if (ValNumEl != PtrNumEl)
             return Error(
                 ID.Loc,
@@ -5572,6 +5572,11 @@ int LLParser::ParseGetElementPtr(Instruction *&Inst, PerFunctionState &PFS) {
 
   SmallVector<Value*, 16> Indices;
   bool AteExtraComma = false;
+  // GEP returns a vector of pointers if at least one of parameters is a vector.
+  // All vector parameters should have the same vector width.
+  unsigned GEPWidth = BaseType->isVectorTy() ?
+    BaseType->getVectorNumElements() : 0;
+
   while (EatIfPresent(lltok::comma)) {
     if (Lex.getKind() == lltok::MetadataVar) {
       AteExtraComma = true;
@@ -5580,14 +5585,13 @@ int LLParser::ParseGetElementPtr(Instruction *&Inst, PerFunctionState &PFS) {
     if (ParseTypeAndValue(Val, EltLoc, PFS)) return true;
     if (!Val->getType()->getScalarType()->isIntegerTy())
       return Error(EltLoc, "getelementptr index must be an integer");
-    if (Val->getType()->isVectorTy() != Ptr->getType()->isVectorTy())
-      return Error(EltLoc, "getelementptr index type missmatch");
+
     if (Val->getType()->isVectorTy()) {
-      unsigned ValNumEl = cast<VectorType>(Val->getType())->getNumElements();
-      unsigned PtrNumEl = cast<VectorType>(Ptr->getType())->getNumElements();
-      if (ValNumEl != PtrNumEl)
+      unsigned ValNumEl = Val->getType()->getVectorNumElements();
+      if (GEPWidth && GEPWidth != ValNumEl)
         return Error(EltLoc,
           "getelementptr vector index has a wrong number of elements");
+      GEPWidth = ValNumEl;
     }
     Indices.push_back(Val);
   }