X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FCodeGen%2FTwoAddressInstructionPass.cpp;h=1e30821dc741b6da596c16afdcb9cd195afafbeb;hb=6dc18d8d3a86509edf747a3cddcc0104ef710cc3;hp=ac4c1bb3ace18fbf218a8ab663bdb06a24477259;hpb=63295d884ca806162aaa2772462735348692f8e5;p=oota-llvm.git

diff --git a/lib/CodeGen/TwoAddressInstructionPass.cpp b/lib/CodeGen/TwoAddressInstructionPass.cpp
index ac4c1bb3ace..1e30821dc74 100644
--- a/lib/CodeGen/TwoAddressInstructionPass.cpp
+++ b/lib/CodeGen/TwoAddressInstructionPass.cpp
@@ -45,6 +45,7 @@
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/raw_ostream.h"
 #include "llvm/Target/TargetInstrInfo.h"
 #include "llvm/Target/TargetMachine.h"
 #include "llvm/Target/TargetRegisterInfo.h"
@@ -188,7 +189,7 @@ sink3AddrInstruction(MachineInstr *MI, unsigned SavedReg,
 
   // Check if it's safe to move this instruction.
   bool SeenStore = true; // Be conservative.
-  if (!MI->isSafeToMove(TII, AA, SeenStore))
+  if (!MI->isSafeToMove(AA, SeenStore))
     return false;
 
   unsigned DefReg = 0;
@@ -860,7 +861,7 @@ rescheduleMIBelowKill(MachineBasicBlock::iterator &mi,
     return false;
 
   bool SeenStore = true;
-  if (!MI->isSafeToMove(TII, AA, SeenStore))
+  if (!MI->isSafeToMove(AA, SeenStore))
     return false;
 
   if (TII->getInstrLatency(InstrItins, MI) > 1)
@@ -1047,7 +1048,7 @@ rescheduleKillAboveMI(MachineBasicBlock::iterator &mi,
     return false;
 
   bool SeenStore = true;
-  if (!KillMI->isSafeToMove(TII, AA, SeenStore))
+  if (!KillMI->isSafeToMove(AA, SeenStore))
     return false;
 
   SmallSet<unsigned, 2> Uses;
@@ -1206,12 +1207,24 @@ tryInstructionTransform(MachineBasicBlock::iterator &mi,
     }
   }
 
+  // If the instruction is convertible to 3 Addr, instead
+  // of returning try 3 Addr transformation aggresively and
+  // use this variable to check later. Because it might be better.
+  // For example, we can just use `leal (%rsi,%rdi), %eax` and `ret`
+  // instead of the following code.
+  //   addl	%esi, %edi
+  //   movl	%edi, %eax
+  //   ret
+  bool Commuted = false;
+
   // If it's profitable to commute, try to do so.
   if (TryCommute && commuteInstruction(mi, regB, regC, Dist)) {
+    Commuted = true;
     ++NumCommuted;
     if (AggressiveCommute)
       ++NumAggrCommuted;
-    return false;
+    if (!MI.isConvertibleTo3Addr())
+      return false;
   }
 
   if (shouldOnlyCommute)
@@ -1219,7 +1232,7 @@ tryInstructionTransform(MachineBasicBlock::iterator &mi,
 
   // If there is one more use of regB later in the same MBB, consider
   // re-schedule this MI below it.
-  if (EnableRescheduling && rescheduleMIBelowKill(mi, nmi, regB)) {
+  if (!Commuted && EnableRescheduling && rescheduleMIBelowKill(mi, nmi, regB)) {
     ++NumReSchedDowns;
     return true;
   }
@@ -1236,6 +1249,10 @@ tryInstructionTransform(MachineBasicBlock::iterator &mi,
     }
   }
 
+  // Return if it is commuted but 3 addr conversion is failed.
+  if (Commuted)
+    return false;
+
   // If there is one more use of regB later in the same MBB, consider
   // re-schedule it before this MI if it's legal.
   if (EnableRescheduling && rescheduleKillAboveMI(mi, nmi, regB)) {