RPCS3/llvm-mirror
1
0
Fork 0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-11-26 04:32:44 +01:00
Code Issues Projects Releases Wiki Activity

[X86] getFauxShuffleMask - drop unnecessary computeKnownBits OR(X,Y) shuffle decoding.

Browse Source 
Now that rG47cea9e82dda941e lets us aggressively decode multi-use shuffles for the OR(SHUFFLE(),SHUFFLE()) case we don't need the computeKnownBits variant any more.
This commit is contained in:
Simon Pilgrim 2020-08-04 15:57:31 +01:00
parent 5f8db00af1
commit 0afbf1f839
1 changed files with 0 additions and 34 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

34
lib/Target/X86/X86ISelLowering.cpp
View File

@ -7360,40 +7360,6 @@ static bool getFauxShuffleMask(SDValue N, const APInt &DemandedElts,
return true;
}
case ISD::OR: {
// Inspect each operand at the byte level. We can merge these into a
// blend shuffle mask if for each byte at least one is masked out (zero).
KnownBits Known0 =
DAG.computeKnownBits(N.getOperand(0), DemandedElts, Depth + 1);
KnownBits Known1 =
DAG.computeKnownBits(N.getOperand(1), DemandedElts, Depth + 1);
if (Known0.One.isNullValue() && Known1.One.isNullValue()) {
bool IsByteMask = true;
APInt ZeroMask = APInt::getNullValue(NumBytesPerElt);
APInt SelectMask = APInt::getNullValue(NumBytesPerElt);
for (unsigned i = 0; i != NumBytesPerElt && IsByteMask; ++i) {
unsigned LHS = Known0.Zero.extractBits(8, i * 8).getZExtValue();
unsigned RHS = Known1.Zero.extractBits(8, i * 8).getZExtValue();
if (LHS == 255 && RHS == 0)
SelectMask.setBit(i);
else if (LHS == 255 && RHS == 255)
ZeroMask.setBit(i);
else if (!(LHS == 0 && RHS == 255))
IsByteMask = false;
}
if (IsByteMask) {
for (unsigned i = 0; i != NumSizeInBytes; i += NumBytesPerElt) {
for (unsigned j = 0; j != NumBytesPerElt; ++j) {
unsigned Ofs = (SelectMask[j] ? NumSizeInBytes : 0);
int Idx = (ZeroMask[j] ? (int)SM_SentinelZero : (i + j + Ofs));
Mask.push_back(Idx);
}
}
Ops.push_back(N.getOperand(0));
Ops.push_back(N.getOperand(1));
return true;
}
}
// Handle OR(SHUFFLE,SHUFFLE) case where one source is zero and the other
// is a valid shuffle index.
SDValue N0 = peekThroughBitcasts(N.getOperand(0));