[llvm-commits] [llvm] r49059 - /llvm/trunk/lib/Target/X86/X86InstrInfo.cpp

[Evan Cheng]

Author: evancheng
Date: Tue Apr  1 18:26:12 2008
New Revision: 49059

URL: http://llvm.org/viewvc/llvm-project?rev=49059&view=rev
Log:
ReMat of load from stub in pic mode extends the life of pic base. Currently spiller doesn't do a good job of estimating the impact. Disable for now.

Modified:
    llvm/trunk/lib/Target/X86/X86InstrInfo.cpp

Modified: llvm/trunk/lib/Target/X86/X86InstrInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86InstrInfo.cpp?rev=49059&r1=49058&r2=49059&view=diff

==============================================================================
--- llvm/trunk/lib/Target/X86/X86InstrInfo.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86InstrInfo.cpp Tue Apr  1 18:26:12 2008
@@ -37,6 +37,10 @@
                     cl::desc("Print instructions that the allocator wants to"
                              " fuse, but the X86 backend currently can't"),
                     cl::Hidden);
+  cl::opt<bool>
+  ReMatPICStubLoad("remat-pic-stub-load",
+                   cl::desc("Re-materialize load from stub in PIC mode"),
+                   cl::init(false), cl::Hidden);
 }
 
 X86InstrInfo::X86InstrInfo(X86TargetMachine &tm)
@@ -782,6 +786,8 @@
         if (BaseReg == 0)
           return true;
         // Allow re-materialization of PIC load.
+        if (!ReMatPICStubLoad && MI->getOperand(4).isGlobal())
+          return false;
         MachineRegisterInfo &MRI = MI->getParent()->getParent()->getRegInfo();
         bool isPICBase = false;
         for (MachineRegisterInfo::def_iterator I = MRI.def_begin(BaseReg),