From 71b9d94d6ba2933df0f7936c44cdb344336d46ef Mon Sep 17 00:00:00 2001 From: Andrew Trick Date: Mon, 17 Jun 2013 21:45:18 +0000 Subject: MI-Sched: handle ReadAdvance latencies as used by Swift. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184135 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/TargetSchedule.cpp | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/lib/CodeGen/TargetSchedule.cpp b/lib/CodeGen/TargetSchedule.cpp index 53cd11c5da..64ee9d1c46 100644 --- a/lib/CodeGen/TargetSchedule.cpp +++ b/lib/CodeGen/TargetSchedule.cpp @@ -201,7 +201,10 @@ unsigned TargetSchedModel::computeOperandLatency( if (UseDesc->NumReadAdvanceEntries == 0) return Latency; unsigned UseIdx = findUseIdx(UseMI, UseOperIdx); - return Latency - STI->getReadAdvanceCycles(UseDesc, UseIdx, WriteID); + int Advance = STI->getReadAdvanceCycles(UseDesc, UseIdx, WriteID); + if (Advance > 0 && (unsigned)Advance > Latency) // unsigned wrap + return 0; + return Latency - Advance; } // If DefIdx does not exist in the model (e.g. implicit defs), then return // unit latency (defaultDefLatency may be too conservative). -- cgit v1.2.3