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[PPC] Early exit loop in getPrefLoopAlignment().
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Authored by mcrosier on Dec 11 2015, 2:08 PM.

Reviewers

hfinkel

Summary

Just something I saw in passing..

Chad

mcrosier retitled this revision from to [PPC] Early exit loop in getPrefLoopAlignment()..

mcrosier updated this object.

mcrosier added a reviewer: hfinkel.

mcrosier added a subscriber: llvm-commits.

LGTM.

This revision is now accepted and ready to land.Dec 11 2015, 4:07 PM

Committed r255497.

Path

Size

lib/

Target/

PowerPC/

5 lines

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	break;			break;

	const PPCInstrInfo *TII = Subtarget.getInstrInfo();			const PPCInstrInfo *TII = Subtarget.getInstrInfo();

	// For small loops (between 5 and 8 instructions), align to a 32-byte			// For small loops (between 5 and 8 instructions), align to a 32-byte
	// boundary so that the entire loop fits in one instruction-cache line.			// boundary so that the entire loop fits in one instruction-cache line.
	uint64_t LoopSize = 0;			uint64_t LoopSize = 0;
	for (auto I = ML->block_begin(), IE = ML->block_end(); I != IE; ++I)			for (auto I = ML->block_begin(), IE = ML->block_end(); I != IE; ++I)
	for (auto J = (I)->begin(), JE = (I)->end(); J != JE; ++J)			for (auto J = (I)->begin(), JE = (I)->end(); J != JE; ++J) {
	LoopSize += TII->GetInstSizeInBytes(J);			LoopSize += TII->GetInstSizeInBytes(J);
				if (LoopSize > 32)
				break;
				}

	if (LoopSize > 16 && LoopSize <= 32)			if (LoopSize > 16 && LoopSize <= 32)
	return 5;			return 5;

	break;			break;
	}			}
	}			}

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