Added code for correct reordering of call arguments
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@1234 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/SparcV9/SparcV9RegInfo.cpp b/lib/Target/SparcV9/SparcV9RegInfo.cpp
index 4d581f7..fed83a9 100644
--- a/lib/Target/SparcV9/SparcV9RegInfo.cpp
+++ b/lib/Target/SparcV9/SparcV9RegInfo.cpp
@@ -590,6 +590,8 @@
// Now color all args of the call instruction
+ vector <MachineInstr *> AddedInstrnsBefore;
+
unsigned NumOfCallArgs = getCallInstNumArgs( CallMI );
for(unsigned argNo=0, i=0; i < NumOfCallArgs; ++i, ++argNo ) {
@@ -666,7 +668,7 @@
AdMI = cpReg2MemMI(UniLRReg, getStackPointer(), argOffset, RegType );
}
- CallAI->InstrnsBefore.push_back( AdMI ); // Now add the instruction
+ AddedInstrnsBefore.push_back( AdMI ); // Now add the instruction
}
else { // LR is not colored (i.e., spilled)
@@ -681,7 +683,7 @@
AdMI = cpMem2RegMI(getFramePointer(), LR->getSpillOffFromFP(),
UniArgReg, RegType );
- CallAI->InstrnsBefore.push_back( AdMI ); // Now add the instruction
+ AddedInstrnsBefore.push_back( AdMI ); // Now add the instruction
}
else {
@@ -696,6 +698,7 @@
// above method since we cannot find LVSetBefore without the BB
int TReg = PRA.getRegNotUsedByThisInst( LR->getRegClass(), CallMI );
+
int TmpOff = PRA.mcInfo.pushTempValue(target,
target.findOptimalStorageSize(LR->getType()));
// getStackOffsets().getNewTmpPosOffFromFP();
@@ -715,19 +718,51 @@
TReg, RegType );
Ad3 = cpReg2MemMI(TReg, getStackPointer(), argOffset, RegType );
Ad4 = cpMem2RegMI(getFramePointer(), TmpOff, TReg, RegType );
+
+ // We directly add to CallAI->InstrnsBefore instead of adding to
+ // AddedInstrnsBefore since these instructions must not be
+ // reordered.
CallAI->InstrnsBefore.push_back( Ad1 );
CallAI->InstrnsBefore.push_back( Ad2 );
CallAI->InstrnsBefore.push_back( Ad3 );
CallAI->InstrnsBefore.push_back( Ad4 );
+
+ cerr << "\n Caution: Call arg moved from stack to stack";
}
}
} // for each parameter in call instruction
+
+ // if we added any instruction before the call instruction, verify
+ // that they are in the proper order and if not, reorder them
+
+ if( ! AddedInstrnsBefore.empty() ) {
+
+ if( DEBUG_RA) {
+ cerr << "\nCalling reorder with instrns: \n";
+ for(unsigned i=0; i < AddedInstrnsBefore.size(); i++)
+ cerr << *(AddedInstrnsBefore[i]);
+ }
+
+ vector <MachineInstr *> TmpVec;
+ OrderAddedInstrns(AddedInstrnsBefore, TmpVec);
+
+ if( DEBUG_RA) {
+ cerr << "\nAfter reordering instrns: \n";
+ for(unsigned i=0; i < TmpVec.size(); i++)
+ cerr << *(TmpVec[i]);
+ }
+
+ // copy the results back from TmpVec to InstrnsBefore
+ for(unsigned i=0; i < TmpVec.size(); i++)
+ CallAI->InstrnsBefore.push_back( TmpVec[i] );
+ }
+
+
// Reset optional args area again to be safe
- //
PRA.mcInfo.resetOptionalArgs(target);
@@ -1265,3 +1300,201 @@
cerr << "]" << endl;
}
}
+
+//---------------------------------------------------------------------------
+// This method examines instructions inserted by RegAlloc code before a
+// machine instruction to detect invalid orders that destroy values before
+// they are used. If it detects such conditions, it reorders the instructions.
+//
+// The unordered instructions come in the UnordVec. These instructions are
+// instructions inserted by RegAlloc. All suhc instruction MUST have
+// their USES BEFORE THE DEFS.
+
+// The UnordVec & OrdVec must be DISTINCT. The OrdVec must be empty when
+// this method is called.
+
+// This method uses two vectors for efficiency in accessing
+
+//---------------------------------------------------------------------------
+void UltraSparcRegInfo::OrderAddedInstrns( vector<MachineInstr *> &UnordVec,
+ vector<MachineInstr *> &OrdVec) const{
+
+ /*
+ Problem: We can have instructions inserted by RegAlloc like
+ 1. add %ox %g0 %oy
+ 2. add %oy %g0 %oz, where z!=x or z==x
+
+ This is wrong since %oy used by 2 is overwritten by 1
+ */
+
+ /* Algorithm:
+
+ Round 1:
+ For each instruction 'Inst' in UnordVec, starting from UnordVec.begin,
+ let Def be the destination reg of instr.
+ For each use 'Use' of the following instruction
+ If Def==Use continue
+ If no use is found, push back 'Inst' to OrdVec
+
+ If no inst is left in UnordVec by the end of Round1, return
+
+ Round 2:
+ For each inst 'Inst' left in UnordVec
+ For each use 'Use' in Inst
+ If threre is NO Def for this Use in an inst in OrdVec
+ push back Inst
+ Else
+ push_front a stack save instr mem location "Loc"
+ push_back a restore inst to load to Use from Loc
+ discard Inst (assert that one operand is %g0)
+
+ */
+
+ bool CouldMoveAll = true;
+
+
+ vector<MachineInstr *>::iterator DefIt = UnordVec.begin();
+
+ for( ; DefIt != UnordVec.end(); ++DefIt ) {
+
+ // for each instruction in the UnordVec do ...
+
+ MachineInstr *DefInst = *DefIt;
+
+ // cerr << "\nDefInst = " << *DefInst;
+
+ for(unsigned OpNumD=0; OpNumD < DefInst->getNumOperands(); ++OpNumD) {
+
+ MachineOperand& DefOp = DefInst->getOperand(OpNumD);
+
+ if( DefOp.opIsDef() &&
+ DefOp.getOperandType() == MachineOperand::MO_MachineRegister) {
+
+ // If the operand in DefInst is a def ...
+
+ bool DefEqUse = false;
+
+ vector<MachineInstr *>::iterator UseIt = DefIt;
+ UseIt++;
+
+ for( ; UseIt != UnordVec.end(); ++UseIt ) {
+
+ // for each inst (UseInst) that is below the DefInst do ...
+
+ MachineInstr *UseInst = *UseIt;
+
+ for(unsigned OpNumU=0; OpNumU < UseInst->getNumOperands(); ++OpNumU){
+
+ MachineOperand& UseOp = UseInst->getOperand(OpNumU);
+
+ if( ! UseOp.opIsDef() &&
+ UseOp.getOperandType() == MachineOperand::MO_MachineRegister) {
+
+ // if use is a register ...
+
+ if( DefOp.getMachineRegNum() == UseOp.getMachineRegNum() ) {
+
+ // if Def and this use are the same, it means that this use
+ // is destroyed by a def before it is used
+
+ DefEqUse = true;
+ CouldMoveAll = false;
+
+ cerr << "\nReordered Ins (Moved up): " << *UseInst;
+ break;
+
+ } // if two registers are equal
+
+ } // if use is a register
+
+ } // for all uses
+
+ }// for all use instructions
+
+ if( ! DefEqUse ) {
+ // cerr << "\nMoved Inst = " << *DefInst;
+ OrdVec.push_back(DefInst);
+ *DefIt = NULL;
+ }
+ else
+ break; // exit the loop since we can't move DefInst
+
+ } // if Def is a machine register
+
+ } // for all Defs in DefInst (there should be only 1)
+
+ } // for all instructions in the UnordVec
+
+
+ if( CouldMoveAll ) {
+ assert( (UnordVec.size() == OrdVec.size()) &&
+ "Different Vec Sizes after reordering");
+ return;
+ }
+
+
+ // We are here because there were two instructions like:
+ // 1. add %ox %g0 %oy
+ // 2. add %oy %g0 %oz, where z!=x or z==x
+ // and hence we could not move 1 to the OrdVec
+
+ // cerr << "\nCaution: Added instructions will be RE-ORDERED !@!@!";
+
+ vector< MachineInstr *>::iterator UnordIt = UnordVec.begin();
+
+ for( ; UnordIt != UnordVec.end(); ++UnordIt ) {
+
+ MachineInstr *UnordInst = *UnordIt;
+ if( UnordInst == NULL ) continue;
+
+ for(unsigned OpNumU=0; OpNumU < UnordInst->getNumOperands(); ++OpNumU) {
+
+ MachineOperand& UseOp = UnordInst->getOperand(OpNumU);
+
+ if( ! UseOp.opIsDef() &&
+ UseOp.getOperandType() == MachineOperand::MO_MachineRegister) {
+
+ if( UseOp.getMachineRegNum() == getZeroRegNum() )
+ continue;
+
+ // for all uses of UnordInst
+ bool DefEqUse = false;
+
+ vector<MachineInstr *>::iterator OrdIt = OrdVec.begin();
+
+ for( ; OrdIt != OrdVec.end(); ++OrdIt ) {
+
+ MachineInstr *OrdInst = *OrdIt ;
+
+ for(unsigned OpNumO=0; OpNumO < OrdInst->getNumOperands(); ++OpNumO){
+
+ MachineOperand& DefOp = OrdInst->getOperand(OpNumO);
+
+ if( DefOp.opIsDef() &&
+ DefOp.getOperandType() == MachineOperand::MO_MachineRegister) {
+
+ if( DefOp.getMachineRegNum() == UseOp.getMachineRegNum() ) {
+
+ DefEqUse = true;
+ assert(0 && "Insert save/restre code for reordering");
+
+ } // if two registers are equal
+
+ } // if Def is a register
+
+ } // for all defs
+
+ } // for each instr in OrdVec
+
+ if( !DefEqUse ) {
+ OrdVec.push_back( UnordInst );
+ cerr << "\nReordered instr (Moved Down): " << *UnordInst;
+ }
+
+ } // if the operand in UnordInst is a use
+
+ } // for each use in the UnordInst
+
+ } // for each UnordInst in UnordVec
+
+}