Make sure to check splats of every constant we can, handle splat(31) by

being a bit more clever, add support for odd splats from -31 to -17.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@27764 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2006-04-17 18:09:22 +00:00
parent 51c9c43656
commit dbce85dedf

View File

@ -1127,6 +1127,9 @@ static SDOperand LowerBUILD_VECTOR(SDOperand Op, SelectionDAG &DAG) {
if (SextVal >= -16 && SextVal <= 15)
return BuildSplatI(SextVal, SplatSize, Op.getValueType(), DAG);
// Two instruction sequences.
// If this value is in the range [-32,30] and is even, use:
// tmp = VSPLTI[bhw], result = add tmp, tmp
if (SextVal >= -32 && SextVal <= 30 && (SextVal & 1) == 0) {
@ -1154,7 +1157,7 @@ static SDOperand LowerBUILD_VECTOR(SDOperand Op, SelectionDAG &DAG) {
unsigned SplatBitSize = SplatSize*8;
static const char SplatCsts[] = {
-1, 1, -2, 2, -3, 3, -4, 4, -5, 5, -6, 6, -7, 7,
-8, 8, -9, 9, -10, 10, -11, 11, -12, 12, -13, 14, -15
-8, 8, -9, 9, -10, 10, -11, 11, -12, 12, -13, 13, 14, -14, 15, -15, -16
};
for (unsigned idx = 0; idx < sizeof(SplatCsts)/sizeof(SplatCsts[0]); ++idx){
// Indirect through the SplatCsts array so that we favor 'vsplti -1' for
@ -1225,10 +1228,16 @@ static SDOperand LowerBUILD_VECTOR(SDOperand Op, SelectionDAG &DAG) {
// Three instruction sequences.
// Otherwise, in range [17,29]: (vsplti 15) + (vsplti C).
if (SextVal >= 0 && SextVal <= 29) {
SDOperand LHS = BuildSplatI(15, SplatSize, Op.getValueType(), DAG);
SDOperand RHS = BuildSplatI(SextVal-15, SplatSize, Op.getValueType(),DAG);
// Odd, in range [17,31]: (vsplti C)-(vsplti -16).
if (SextVal >= 0 && SextVal <= 31) {
SDOperand LHS = BuildSplatI(SextVal-16, SplatSize, Op.getValueType(),DAG);
SDOperand RHS = BuildSplatI(-16, SplatSize, Op.getValueType(), DAG);
return DAG.getNode(ISD::SUB, Op.getValueType(), LHS, RHS);
}
// Odd, in range [-31,-17]: (vsplti C)+(vsplti -16).
if (SextVal >= -31 && SextVal <= 0) {
SDOperand LHS = BuildSplatI(SextVal+16, SplatSize, Op.getValueType(),DAG);
SDOperand RHS = BuildSplatI(-16, SplatSize, Op.getValueType(), DAG);
return DAG.getNode(ISD::ADD, Op.getValueType(), LHS, RHS);
}
}