[llvm-commits] [llvm] r103823 - /llvm/trunk/lib/CodeGen/RegAllocFast.cpp

[Jakob Stoklund Olesen]

Author: stoklund
Date: Fri May 14 16:55:52 2010
New Revision: 103823

URL: http://llvm.org/viewvc/llvm-project?rev=103823&view=rev
Log:
Avoid scanning the long tail of physreg operands on calls

Modified:
    llvm/trunk/lib/CodeGen/RegAllocFast.cpp

Modified: llvm/trunk/lib/CodeGen/RegAllocFast.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/RegAllocFast.cpp?rev=103823&r1=103822&r2=103823&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/RegAllocFast.cpp (original)
+++ llvm/trunk/lib/CodeGen/RegAllocFast.cpp Fri May 14 16:55:52 2010
@@ -663,12 +663,18 @@
 
     // First scan.
     // Mark physreg uses and early clobbers as used.
+    // Find the end of the virtreg operands
+    unsigned VirtOpEnd = 0;
     for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
       MachineOperand &MO = MI->getOperand(i);
       if (!MO.isReg()) continue;
       unsigned Reg = MO.getReg();
-      if (!Reg || !TargetRegisterInfo::isPhysicalRegister(Reg) ||
-          ReservedRegs.test(Reg)) continue;
+      if (!Reg) continue;
+      if (TargetRegisterInfo::isVirtualRegister(Reg)) {
+        VirtOpEnd = i+1;
+        continue;
+      }
+      if (ReservedRegs.test(Reg)) continue;
       if (MO.isUse()) {
         usePhysReg(MO);
       } else if (MO.isEarlyClobber()) {
@@ -677,11 +683,10 @@
       }
     }
 
-
     // Second scan.
     // Allocate virtreg uses and early clobbers.
     // Collect VirtKills
-    for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+    for (unsigned i = 0; i != VirtOpEnd; ++i) {
       MachineOperand &MO = MI->getOperand(i);
       if (!MO.isReg()) continue;
       unsigned Reg = MO.getReg();