[llvm-branch-commits] [llvm-branch] r80552 - in /llvm/branches/release_26: lib/CodeGen/VirtRegRewriter.cpp test/CodeGen/X86/2009-08-23-SubRegReuseUndo.ll

[Tanya Lattner]

Author: tbrethou
Date: Mon Aug 31 01:29:32 2009
New Revision: 80552

URL: http://llvm.org/viewvc/llvm-project?rev=80552&view=rev
Log:
Merge from mainline.
When undoing a reuse in ReuseInfo::GetRegForReload, check if it was only a
sub-register being used. The MachineOperand::getSubReg() method is only valid
for virtual registers, so we have to recover the sub-register index manually.


Added:
    llvm/branches/release_26/test/CodeGen/X86/2009-08-23-SubRegReuseUndo.ll
      - copied unchanged from r79855, llvm/trunk/test/CodeGen/X86/2009-08-23-SubRegReuseUndo.ll
Modified:
    llvm/branches/release_26/lib/CodeGen/VirtRegRewriter.cpp

Modified: llvm/branches/release_26/lib/CodeGen/VirtRegRewriter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/branches/release_26/lib/CodeGen/VirtRegRewriter.cpp?rev=80552&r1=80551&r2=80552&view=diff

==============================================================================
--- llvm/branches/release_26/lib/CodeGen/VirtRegRewriter.cpp (original)
+++ llvm/branches/release_26/lib/CodeGen/VirtRegRewriter.cpp Mon Aug 31 01:29:32 2009
@@ -803,6 +803,21 @@
         ReusedOp NewOp = Op;
         Reuses.erase(Reuses.begin()+ro);
 
+        // MI may be using only a sub-register of PhysRegUsed.
+        unsigned RealPhysRegUsed = MI->getOperand(NewOp.Operand).getReg();
+        unsigned SubIdx = 0;
+        assert(TargetRegisterInfo::isPhysicalRegister(RealPhysRegUsed) &&
+               "A reuse cannot be a virtual register");
+        if (PRRU != RealPhysRegUsed) {
+          // What was the sub-register index?
+          unsigned SubReg;
+          for (SubIdx = 1; (SubReg = TRI->getSubReg(PRRU, SubIdx)); SubIdx++)
+            if (SubReg == RealPhysRegUsed)
+              break;
+          assert(SubReg == RealPhysRegUsed &&
+                 "Operand physreg is not a sub-register of PhysRegUsed");
+        }
+
         // Ok, we're going to try to reload the assigned physreg into the
         // slot that we were supposed to in the first place.  However, that
         // register could hold a reuse.  Check to see if it conflicts or
@@ -835,7 +850,6 @@
         Spills.ClobberPhysReg(NewPhysReg);
         Spills.ClobberPhysReg(NewOp.PhysRegReused);
 
-        unsigned SubIdx = MI->getOperand(NewOp.Operand).getSubReg();
         unsigned RReg = SubIdx ? TRI->getSubReg(NewPhysReg, SubIdx) : NewPhysReg;
         MI->getOperand(NewOp.Operand).setReg(RReg);
         MI->getOperand(NewOp.Operand).setSubReg(0);