[llvm-commits] [llvm] r75847 - /llvm/trunk/lib/CodeGen/RegisterScavenging.cpp

[Jakob Stoklund Olesen]

Author: stoklund
Date: Wed Jul 15 17:32:11 2009
New Revision: 75847

URL: http://llvm.org/viewvc/llvm-project?rev=75847&view=rev
Log:
Fix bug in RegScavenger::scavengeRegister().

Reserved registers are not candidates for scavenging, and they were removed
from the candidate list like this:

CreateRegClassMask(RC, Candidates);
Candidates ^= ReservedRegs;

However, when there are reserved registers outside RC, this causes invalid
bits to be set in Candidates.

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

Modified: llvm/trunk/lib/CodeGen/RegisterScavenging.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/RegisterScavenging.cpp?rev=75847&r1=75846&r2=75847&view=diff

==============================================================================
--- llvm/trunk/lib/CodeGen/RegisterScavenging.cpp (original)
+++ llvm/trunk/lib/CodeGen/RegisterScavenging.cpp Wed Jul 15 17:32:11 2009
@@ -426,7 +426,7 @@
   // Mask off the registers which are not in the TargetRegisterClass.
   BitVector Candidates(NumPhysRegs, false);
   CreateRegClassMask(RC, Candidates);
-  Candidates ^= ReservedRegs;  // Do not include reserved registers.
+  Candidates ^= ReservedRegs & Candidates; // Do not include reserved registers.
 
   // Exclude all the registers being used by the instruction.
   for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) {