isSplatMask() bug: first element can be an undef.

llvm-svn: 27847
This commit is contained in:
Evan Cheng 2006-04-19 23:28:59 +00:00
parent 73eb58e1a2
commit 4a1b0d3292
1 changed files with 18 additions and 6 deletions

View File

@ -1753,17 +1753,29 @@ static bool isSplatMask(SDNode *N) {
// This is a splat operation if each element of the permute is the same, and
// if the value doesn't reference the second vector.
SDOperand Elt = N->getOperand(0);
assert(isa<ConstantSDNode>(Elt) && "Invalid VECTOR_SHUFFLE mask!");
for (unsigned i = 1, e = N->getNumOperands(); i != e; ++i) {
unsigned NumElems = N->getNumOperands();
SDOperand ElementBase;
unsigned i = 0;
for (; i != NumElems; ++i) {
SDOperand Elt = N->getOperand(i);
if (ConstantSDNode *EltV = dyn_cast<ConstantSDNode>(Elt)) {
ElementBase = Elt;
break;
}
}
if (!ElementBase.Val)
return false;
for (; i != NumElems; ++i) {
SDOperand Arg = N->getOperand(i);
if (Arg.getOpcode() == ISD::UNDEF) continue;
assert(isa<ConstantSDNode>(Arg) && "Invalid VECTOR_SHUFFLE mask!");
if (Arg != Elt) return false;
if (Arg != ElementBase) return false;
}
// Make sure it is a splat of the first vector operand.
return cast<ConstantSDNode>(Elt)->getValue() < N->getNumOperands();
return cast<ConstantSDNode>(ElementBase)->getValue() < NumElems;
}
/// isSplatMask - Return true if the specified VECTOR_SHUFFLE operand specifies
@ -1771,7 +1783,7 @@ static bool isSplatMask(SDNode *N) {
bool X86::isSplatMask(SDNode *N) {
assert(N->getOpcode() == ISD::BUILD_VECTOR);
// We can only splat 64-bit, and 32-bit quantities.
// We can only splat 64-bit, and 32-bit quantities with a single instruction.
if (N->getNumOperands() != 4 && N->getNumOperands() != 2)
return false;
return ::isSplatMask(N);