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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73761 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index 345f172deb76652aa19a337043970865a3bd5434..2443625d4bdb88dc0f04f523d3238eb9446c137b 100644 (file)
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -294,6 +294,10 @@ ARMTargetLowering::ARMTargetLowering(TargetMachine &TM)
 
   if (!Subtarget->isThumb()) {
     // Use branch latency information to determine if-conversion limits.
+    // FIXME: If-converter should use instruction latency of the branch being
+    // eliminated to compute the threshold. For ARMv6, the branch "latency"
+    // varies depending on whether it's dynamically or statically predicted
+    // and on whether the destination is in the prefetch buffer.
     const TargetInstrInfo *TII = getTargetMachine().getInstrInfo();
     const InstrItineraryData &InstrItins = Subtarget->getInstrItineraryData();
     unsigned Latency= InstrItins.getLatency(TII->get(ARM::Bcc).getSchedClass());