[llvm-commits] CVS: llvm/lib/Target/Sparc/AddRegNumToValues.cpp

[Misha Brukman]

Changes in directory llvm/lib/Target/Sparc:

AddRegNumToValues.cpp added (r1.1)

---
Log message:

This file provides the `glue' to turn the Value*-based MachineInstrs that
the Sparc instruction selector produces to the unsigned-register-based
MachineInstrs that the target-independent register allocators in the JIT prefer.


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Diffs of the changes:

Index: llvm/lib/Target/Sparc/AddRegNumToValues.cpp
diff -c /dev/null llvm/lib/Target/Sparc/AddRegNumToValues.cpp:1.1
*** /dev/null	Tue May 27 15:05:37 2003
--- llvm/lib/Target/Sparc/AddRegNumToValues.cpp	Tue May 27 15:05:27 2003
***************
*** 0 ****
--- 1,64 ----
+ //===-- AddRegNumToValues.cpp - Adds unsigned register indices for Value* -===//
+ //
+ // This is a placeholder pass, just so that it doesn't intrude too much into
+ // the MachineOperand class: 
+ // * The Sparc back-end uses Value* in instructions for dataflow
+ // * The RegisterAllocator in the JIT expects unsigned register numbers instead
+ //   of Value*
+ //
+ // This pass is an attempt to bridge the gap between the two, without putting an
+ // explicit conversion in the shortest path (i.e., the original LLC codegen).
+ //
+ //===----------------------------------------------------------------------===//
+ 
+ #include "llvm/CodeGen/Passes.h"
+ #include "llvm/CodeGen/MachineFunctionPass.h"
+ #include "llvm/CodeGen/MachineInstr.h"
+ #include "SparcInternals.h"
+ 
+ namespace {
+   struct AddRegNumToValues : MachineFunctionPass {
+     
+     AddRegNumToValues() {}
+     bool runOnMachineFunction(MachineFunction &F);
+   };
+ 
+   static RegisterOpt<AddRegNumToValues>
+   X("add-regnum", "Add reg numbers to Values", createAddRegNumToValuesPass);
+ }
+ 
+ bool AddRegNumToValues::runOnMachineFunction(MachineFunction &F) {
+   unsigned regNum = MRegisterInfo::FirstVirtualRegister;
+   std::map<Value*,unsigned> Value2RegMap;
+ 
+   for (MachineFunction::iterator i = F.begin(), e = F.end(); i != e; ++i) {
+     MachineBasicBlock &BB = *i;
+     for (MachineBasicBlock::iterator Bi = BB.begin(), Be = BB.end();
+          Bi != Be; ++Bi)
+     {
+       MachineInstr *MI = *Bi;
+       
+       // Loop over uses, move from memory into registers
+       for (int i = MI->getNumOperands()-1; i >= 0; --i) {
+         MachineOperand &op = MI->getOperand(i);
+         
+         Value *val = op.getVRegValueOrNull();
+         if (Instruction *inst = dyn_cast<Instruction>(val)) {
+           if (Value2RegMap[val] != 0) {
+             MI->SetRegForOperand(i, Value2RegMap[val]);
+           } else {
+             MI->SetRegForOperand(i, regNum);
+             Value2RegMap[val] = regNum++;
+           }
+         }
+       }
+     }
+   }
+ 
+   Value2RegMap.clear();
+   return false;
+ }
+ 
+ Pass *createAddRegNumToValuesPass() {
+   return new AddRegNumToValues();
+ }