Tighten up checking of the validity of casts. (1) The IR parser would

happily accept things like "sext <2 x i32> to <999 x i64>".  It would
also accept "sext <2 x i32> to i64", though the verifier would catch
that later.  Fixed by having castIsValid check that vector lengths match
except when doing a bitcast.  (2) When creating a cast instruction, check
that the cast is valid (this was already done when creating constexpr
casts).  While there, replace getScalarSizeInBits (used to allow more
vector casts) with getPrimitiveSizeInBits in getCastOpcode and isCastable
since vector to vector casts are now handled explicitly by passing to the
element types; i.e. this bit should result in no functional change.

llvm-svn: 131532

3 files changed, 40 insertions, 32 deletions

diff --git a/llvm/lib/VMCore/Instructions.cpp b/llvm/lib/VMCore/Instructions.cpp
index af1492d356a..91f0febf349 100644
--- a/llvm/lib/VMCore/Instructions.cpp
+++ b/llvm/lib/VMCore/Instructions.cpp
@@ -2076,6 +2076,7 @@ unsigned CastInst::isEliminableCastPair(
 
 CastInst *CastInst::Create(Instruction::CastOps op, Value *S, const Type *Ty, 
   const Twine &Name, Instruction *InsertBefore) {
+  assert(castIsValid(op, S, Ty) && "Invalid cast!");
   // Construct and return the appropriate CastInst subclass
   switch (op) {
     case Trunc:    return new TruncInst    (S, Ty, Name, InsertBefore);
@@ -2098,6 +2099,7 @@ CastInst *CastInst::Create(Instruction::CastOps op, Value *S, const Type *Ty,
 
 CastInst *CastInst::Create(Instruction::CastOps op, Value *S, const Type *Ty,
   const Twine &Name, BasicBlock *InsertAtEnd) {
+  assert(castIsValid(op, S, Ty) && "Invalid cast!");
   // Construct and return the appropriate CastInst subclass
   switch (op) {
     case Trunc:    return new TruncInst    (S, Ty, Name, InsertAtEnd);
@@ -2263,8 +2265,8 @@ bool CastInst::isCastable(const Type *SrcTy, const Type *DestTy) {
       }
 
   // Get the bit sizes, we'll need these
-  unsigned SrcBits = SrcTy->getScalarSizeInBits();   // 0 for ptr
-  unsigned DestBits = DestTy->getScalarSizeInBits(); // 0 for ptr
+  unsigned SrcBits = SrcTy->getPrimitiveSizeInBits();   // 0 for ptr
+  unsigned DestBits = DestTy->getPrimitiveSizeInBits(); // 0 for ptr
 
   // Run through the possibilities ...
   if (DestTy->isIntegerTy()) {                   // Casting to integral
@@ -2348,8 +2350,8 @@ CastInst::getCastOpcode(
       }
 
   // Get the bit sizes, we'll need these
-  unsigned SrcBits = SrcTy->getScalarSizeInBits();   // 0 for ptr
-  unsigned DestBits = DestTy->getScalarSizeInBits(); // 0 for ptr
+  unsigned SrcBits = SrcTy->getPrimitiveSizeInBits();   // 0 for ptr
+  unsigned DestBits = DestTy->getPrimitiveSizeInBits(); // 0 for ptr
 
   // Run through the possibilities ...
   if (DestTy->isIntegerTy()) {                      // Casting to integral
@@ -2463,46 +2465,40 @@ CastInst::castIsValid(Instruction::CastOps op, Value *S, const Type *DstTy) {
   unsigned SrcBitSize = SrcTy->getScalarSizeInBits();
   unsigned DstBitSize = DstTy->getScalarSizeInBits();
 
+  // If these are vector types, get the lengths of the vectors (using zero for
+  // scalar types means that checking that vector lengths match also checks that
+  // scalars are not being converted to vectors or vectors to scalars).
+  unsigned SrcLength = SrcTy->isVectorTy() ?
+    cast<VectorType>(SrcTy)->getNumElements() : 0;
+  unsigned DstLength = DstTy->isVectorTy() ?
+    cast<VectorType>(DstTy)->getNumElements() : 0;
+
   // Switch on the opcode provided
   switch (op) {
   default: return false; // This is an input error
   case Instruction::Trunc:
-    return SrcTy->isIntOrIntVectorTy() &&
-           DstTy->isIntOrIntVectorTy()&& SrcBitSize > DstBitSize;
+    return SrcTy->isIntOrIntVectorTy() && DstTy->isIntOrIntVectorTy() &&
+      SrcLength == DstLength && SrcBitSize > DstBitSize;
   case Instruction::ZExt:
-    return SrcTy->isIntOrIntVectorTy() &&
-           DstTy->isIntOrIntVectorTy()&& SrcBitSize < DstBitSize;
+    return SrcTy->isIntOrIntVectorTy() && DstTy->isIntOrIntVectorTy() &&
+      SrcLength == DstLength && SrcBitSize < DstBitSize;
   case Instruction::SExt: 
-    return SrcTy->isIntOrIntVectorTy() &&
-           DstTy->isIntOrIntVectorTy()&& SrcBitSize < DstBitSize;
+    return SrcTy->isIntOrIntVectorTy() && DstTy->isIntOrIntVectorTy() &&
+      SrcLength == DstLength && SrcBitSize < DstBitSize;
   case Instruction::FPTrunc:
-    return SrcTy->isFPOrFPVectorTy() &&
-           DstTy->isFPOrFPVectorTy() && 
-           SrcBitSize > DstBitSize;
+    return SrcTy->isFPOrFPVectorTy() && DstTy->isFPOrFPVectorTy() &&
+      SrcLength == DstLength && SrcBitSize > DstBitSize;
   case Instruction::FPExt:
-    return SrcTy->isFPOrFPVectorTy() &&
-           DstTy->isFPOrFPVectorTy() && 
-           SrcBitSize < DstBitSize;
+    return SrcTy->isFPOrFPVectorTy() && DstTy->isFPOrFPVectorTy() &&
+      SrcLength == DstLength && SrcBitSize < DstBitSize;
   case Instruction::UIToFP:
   case Instruction::SIToFP:
-    if (const VectorType *SVTy = dyn_cast<VectorType>(SrcTy)) {
-      if (const VectorType *DVTy = dyn_cast<VectorType>(DstTy)) {
-        return SVTy->getElementType()->isIntOrIntVectorTy() &&
-               DVTy->getElementType()->isFPOrFPVectorTy() &&
-               SVTy->getNumElements() == DVTy->getNumElements();
-      }
-    }
-    return SrcTy->isIntOrIntVectorTy() && DstTy->isFPOrFPVectorTy();
+    return SrcTy->isIntOrIntVectorTy() && DstTy->isFPOrFPVectorTy() &&
+      SrcLength == DstLength;
   case Instruction::FPToUI:
   case Instruction::FPToSI:
-    if (const VectorType *SVTy = dyn_cast<VectorType>(SrcTy)) {
-      if (const VectorType *DVTy = dyn_cast<VectorType>(DstTy)) {
-        return SVTy->getElementType()->isFPOrFPVectorTy() &&
-               DVTy->getElementType()->isIntOrIntVectorTy() &&
-               SVTy->getNumElements() == DVTy->getNumElements();
-      }
-    }
-    return SrcTy->isFPOrFPVectorTy() && DstTy->isIntOrIntVectorTy();
+    return SrcTy->isFPOrFPVectorTy() && DstTy->isIntOrIntVectorTy() &&
+      SrcLength == DstLength;
   case Instruction::PtrToInt:
     return SrcTy->isPointerTy() && DstTy->isIntegerTy();
   case Instruction::IntToPtr:
diff --git a/llvm/test/Assembler/invalid_cast.ll b/llvm/test/Assembler/invalid_cast.ll
new file mode 100644
index 00000000000..c5b082b6b8d
--- /dev/null
+++ b/llvm/test/Assembler/invalid_cast.ll
@@ -0,0 +1,6 @@
+; RUN: not llvm-as < %s |& grep {invalid cast opcode}
+
+define <3 x i8> @foo(<4 x i64> %x) {
+  %y = trunc <4 x i64> %x to <3 x i8>
+  ret <3 x i8> %y
+}
diff --git a/llvm/test/Assembler/invalid_cast2.ll b/llvm/test/Assembler/invalid_cast2.ll
new file mode 100644
index 00000000000..f2e7c414e71
--- /dev/null
+++ b/llvm/test/Assembler/invalid_cast2.ll
@@ -0,0 +1,6 @@
+; RUN: not llvm-as < %s |& grep {invalid cast opcode}
+
+define i8 @foo(<4 x i64> %x) {
+  %y = trunc <4 x i64> %x to i8
+  ret i8 %y
+}