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AMDGPU: Check cheaper condition before SignBitIsZero
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Authored by arsenm on Feb 23 2016, 11:17 AM.

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Reviewers

• tstellarAMD
mcrosier

Summary

Don't do an expensive computeKnownBits call when we
can do the cheap check for legal offsets first.

Diff Detail

Event Timeline

arsenm updated this revision to Diff 48841.Feb 23 2016, 11:17 AM

arsenm retitled this revision from to AMDGPU: Check cheaper condition before SignBitIsZero.

arsenm updated this object.

arsenm added a reviewer: • tstellarAMD.

arsenm added a subscriber: llvm-commits.

Herald added a subscriber: arsenm. · View Herald TranscriptFeb 23 2016, 11:17 AM

Looks straight forward.

This revision is now accepted and ready to land.Feb 23 2016, 11:32 AM

wdng added a subscriber: wdng.Feb 23 2016, 2:31 PM

wdng removed a subscriber: wdng.

r261720

Revision Contents

Path

Size

lib/

Target/

AMDGPU/

AMDGPUISelDAGToDAG.cpp

13 lines

Diff 48841

lib/Target/AMDGPU/AMDGPUISelDAGToDAG.cpp

Show First 20 Lines • Show All 1,057 Lines • ▼ Show 20 Lines	bool AMDGPUDAGToDAGISel::SelectMUBUFScratch(SDValue Addr, SDValue &Rsrc,

Rsrc = CurDAG->getRegister(Info->getScratchRSrcReg(), MVT::v4i32);		Rsrc = CurDAG->getRegister(Info->getScratchRSrcReg(), MVT::v4i32);
SOffset = CurDAG->getRegister(Info->getScratchWaveOffsetReg(), MVT::i32);		SOffset = CurDAG->getRegister(Info->getScratchWaveOffsetReg(), MVT::i32);

// (add n0, c1)		// (add n0, c1)
if (CurDAG->isBaseWithConstantOffset(Addr)) {		if (CurDAG->isBaseWithConstantOffset(Addr)) {
SDValue N0 = Addr.getOperand(0);		SDValue N0 = Addr.getOperand(0);
SDValue N1 = Addr.getOperand(1);		SDValue N1 = Addr.getOperand(1);

// Offsets in vaddr must be positive.		// Offsets in vaddr must be positive.
if (CurDAG->SignBitIsZero(N0)) {
ConstantSDNode *C1 = cast<ConstantSDNode>(N1);		ConstantSDNode *C1 = cast<ConstantSDNode>(N1);
if (isLegalMUBUFImmOffset(C1)) {		if (isLegalMUBUFImmOffset(C1) && CurDAG->SignBitIsZero(N0)) {
VAddr = N0;		VAddr = N0;
ImmOffset = CurDAG->getTargetConstant(C1->getZExtValue(), DL, MVT::i16);		ImmOffset = CurDAG->getTargetConstant(C1->getZExtValue(), DL, MVT::i16);
return true;		return true;
}		}
}		}
}

// (node)		// (node)
VAddr = Addr;		VAddr = Addr;
ImmOffset = CurDAG->getTargetConstant(0, DL, MVT::i16);		ImmOffset = CurDAG->getTargetConstant(0, DL, MVT::i16);
return true;		return true;
}		}

bool AMDGPUDAGToDAGISel::SelectMUBUFOffset(SDValue Addr, SDValue &SRsrc,		bool AMDGPUDAGToDAGISel::SelectMUBUFOffset(SDValue Addr, SDValue &SRsrc,
▲ Show 20 Lines • Show All 478 Lines • Show Last 20 Lines