PNaCl: Add support for GCC/LLVM vector extensions

lib/Analysis/NaCl/PNaClABITypeChecker.cpp

 //===- PNaClABITypeChecker.cpp - Verify PNaCl ABI rules -------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // Common type-checking code for module and function-level passes
 //
 //
 //===----------------------------------------------------------------------===//
 
 #include "PNaClABITypeChecker.h"
 #include "llvm/IR/Constant.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/Metadata.h"
 
 using namespace llvm;
 
 bool PNaClABITypeChecker::isValidParamType(const Type *Ty) {
-  if (!isValidScalarType(Ty))
+  if (!(isValidScalarType(Ty) || isValidVectorType(Ty)))
     return false;
   if (const IntegerType *IntTy = dyn_cast<IntegerType>(Ty)) {
     // PNaCl requires function arguments and return values to be 32
     // bits or larger.  This avoids exposing architecture
     // ABI-dependent differences about whether arguments or return
     // values are zero-extended when calling a function with the wrong
     // prototype.
     if (IntTy->getBitWidth() < 32)
       return false;
   }
@@ skipping 20 matching lines @@
              Width == 32 || Width == 64;
     }
     case Type::VoidTyID:
     case Type::FloatTyID:
     case Type::DoubleTyID:
       return true;
     default:
       return false;
   }
 }
+
+// TODO(jfb) Handle 64-bit int and double, and 2xi1.
+bool PNaClABITypeChecker::isValidVectorType(const Type *Ty) {
+  if (!Ty->isVectorTy())
+    return false;
+  unsigned Elems = Ty->getVectorNumElements();
+  const Type *VTy = Ty->getVectorElementType();
+
+  switch (VTy->getTypeID()) {
+  case Type::IntegerTyID: {
+    unsigned Width = cast<const IntegerType>(VTy)->getBitWidth();
+    switch (Width) {
+    case 1: return Elems == 4 || Elems == 8 || Elems == 16;
+    case 8: return Elems == 16;
+    case 16: return Elems == 8;
+    case 32: return Elems == 4;
+    default: return false;
+    }
+  }
+  case Type::FloatTyID:
+    return Elems == 4;
+  default:
+    return false;
+  }
+}