Latency information for ARM v6. It's rough and not yet hooked up. Right now we are only using branch latency to determine if-conversion limits.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73747 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index 943a420..38a2fb9 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -292,6 +292,21 @@
setIfCvtBlockSizeLimit(Subtarget->isThumb() ? 0 : 10);
setIfCvtDupBlockSizeLimit(Subtarget->isThumb() ? 0 : 2);
+ if (!Subtarget->isThumb()) {
+ // Use branch latency information to determine if-conversion limits.
+ const TargetInstrInfo *TII = getTargetMachine().getInstrInfo();
+ const InstrItineraryData &InstrItins = Subtarget->getInstrItineraryData();
+ unsigned Latency = InstrItins.getLatency(TII->get(ARM::BL).getSchedClass());
+ if (Latency > 1) {
+ setIfCvtBlockSizeLimit(Latency-1);
+ if (Latency > 2)
+ setIfCvtDupBlockSizeLimit(Latency-2);
+ } else {
+ setIfCvtBlockSizeLimit(10);
+ setIfCvtDupBlockSizeLimit(2);
+ }
+ }
+
maxStoresPerMemcpy = 1; //// temporary - rewrite interface to use type
// Do not enable CodePlacementOpt for now: it currently runs after the
// ARMConstantIslandPass and messes up branch relaxation and placement