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[DAGCombiner] Remove duplicate code from visitZERO_EXTEND
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Authored by craig.topper on Sep 21 2017, 12:07 AM.

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Summary

This exact block of code exists right below.

LGTM

This revision is now accepted and ready to land.Sep 21 2017, 1:50 AM

This revision was automatically updated to reflect the committed changes.

Path

Size

lib/

CodeGen/

SelectionDAG/

14 lines

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	return DAG.getZExtOrTrunc(Op, SDLoc(N), VT);	return DAG.getZExtOrTrunc(Op, SDLoc(N), VT);
	}	}

	// fold (zext (truncate (load x))) -> (zext (smaller load x))
	// fold (zext (truncate (srl (load x), c))) -> (zext (small load (x+c/n)))
	if (N0.getOpcode() == ISD::TRUNCATE) {
	if (SDValue NarrowLoad = ReduceLoadWidth(N0.getNode())) {
	SDNode *oye = N0.getOperand(0).getNode();
	if (NarrowLoad.getNode() != N0.getNode()) {
	CombineTo(N0.getNode(), NarrowLoad);
	// CombineTo deleted the truncate, if needed, but not what's under it.
	AddToWorklist(oye);
	}
	return SDValue(N, 0); // Return N so it doesn't get rechecked!
	}
	}

	// fold (zext (truncate x)) -> (and x, mask)	// fold (zext (truncate x)) -> (and x, mask)
	if (N0.getOpcode() == ISD::TRUNCATE) {	if (N0.getOpcode() == ISD::TRUNCATE) {
	// fold (zext (truncate (load x))) -> (zext (smaller load x))	// fold (zext (truncate (load x))) -> (zext (smaller load x))
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