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path: root/lib/Target/X86/X86FloatingPoint.cpp
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Diffstat (limited to 'lib/Target/X86/X86FloatingPoint.cpp')
-rw-r--r--lib/Target/X86/X86FloatingPoint.cpp92
1 files changed, 49 insertions, 43 deletions
diff --git a/lib/Target/X86/X86FloatingPoint.cpp b/lib/Target/X86/X86FloatingPoint.cpp
index 329cdd8e75..0a8f4ac478 100644
--- a/lib/Target/X86/X86FloatingPoint.cpp
+++ b/lib/Target/X86/X86FloatingPoint.cpp
@@ -145,6 +145,7 @@ namespace {
void handleOneArgFP(MachineBasicBlock::iterator &I);
void handleOneArgFPRW(MachineBasicBlock::iterator &I);
void handleTwoArgFP(MachineBasicBlock::iterator &I);
+ void handleCompareFP(MachineBasicBlock::iterator &I);
void handleCondMovFP(MachineBasicBlock::iterator &I);
void handleSpecialFP(MachineBasicBlock::iterator &I);
};
@@ -214,7 +215,12 @@ bool FPS::processBasicBlock(MachineFunction &MF, MachineBasicBlock &BB) {
case X86II::ZeroArgFP: handleZeroArgFP(I); break;
case X86II::OneArgFP: handleOneArgFP(I); break; // fstp ST(0)
case X86II::OneArgFPRW: handleOneArgFPRW(I); break; // ST(0) = fsqrt(ST(0))
- case X86II::TwoArgFP: handleTwoArgFP(I); break;
+ case X86II::TwoArgFP:
+ if (I->getOpcode() != X86::FpUCOM && I->getOpcode() != X86::FpUCOMI)
+ handleTwoArgFP(I);
+ else
+ handleCompareFP(I);
+ break;
case X86II::CondMovFP: handleCondMovFP(I); break;
case X86II::SpecialFP: handleSpecialFP(I); break;
default: assert(0 && "Unknown FP Type!");
@@ -226,10 +232,7 @@ bool FPS::processBasicBlock(MachineFunction &MF, MachineBasicBlock &BB) {
unsigned Reg = IB->second;
if (Reg >= X86::FP0 && Reg <= X86::FP6) {
DEBUG(std::cerr << "Register FP#" << Reg-X86::FP0 << " is dead!\n");
- ++I; // Insert fxch AFTER the instruction
- moveToTop(Reg-X86::FP0, I); // Insert fxch if necessary
- --I; // Move to fxch or old instruction
- popStackAfter(I); // Pop the top of the stack, killing value
+ freeStackSlotAfter(I, Reg-X86::FP0);
}
}
@@ -481,8 +484,6 @@ static const TableEntry ForwardST0Table[] = {
{ X86::FpDIV , X86::FDIVST0r },
{ X86::FpMUL , X86::FMULST0r },
{ X86::FpSUB , X86::FSUBST0r },
- { X86::FpUCOM , X86::FUCOMr },
- { X86::FpUCOMI, X86::FUCOMIr },
};
// ReverseST0Table - Map: A = B op C into: ST(0) = ST(i) op ST(0)
@@ -491,8 +492,6 @@ static const TableEntry ReverseST0Table[] = {
{ X86::FpDIV , X86::FDIVRST0r },
{ X86::FpMUL , X86::FMULST0r }, // commutative
{ X86::FpSUB , X86::FSUBRST0r },
- { X86::FpUCOM , ~0 },
- { X86::FpUCOMI, ~0 },
};
// ForwardSTiTable - Map: A = B op C into: ST(i) = ST(0) op ST(i)
@@ -501,8 +500,6 @@ static const TableEntry ForwardSTiTable[] = {
{ X86::FpDIV , X86::FDIVRrST0 },
{ X86::FpMUL , X86::FMULrST0 }, // commutative
{ X86::FpSUB , X86::FSUBRrST0 },
- { X86::FpUCOM , X86::FUCOMr },
- { X86::FpUCOMI, X86::FUCOMIr },
};
// ReverseSTiTable - Map: A = B op C into: ST(i) = ST(i) op ST(0)
@@ -511,8 +508,6 @@ static const TableEntry ReverseSTiTable[] = {
{ X86::FpDIV , X86::FDIVrST0 },
{ X86::FpMUL , X86::FMULrST0 },
{ X86::FpSUB , X86::FSUBrST0 },
- { X86::FpUCOM , ~0 },
- { X86::FpUCOMI, ~0 },
};
@@ -523,11 +518,6 @@ static const TableEntry ReverseSTiTable[] = {
/// ST(i) = fsub ST(0), ST(i)
/// ST(0) = fsubr ST(0), ST(i)
/// ST(i) = fsubr ST(0), ST(i)
-///
-/// In addition to three address instructions, this also handles the FpUCOM
-/// instruction which only has two operands, but no destination. This
-/// instruction is also annoying because there is no "reverse" form of it
-/// available.
///
void FPS::handleTwoArgFP(MachineBasicBlock::iterator &I) {
ASSERT_SORTED(ForwardST0Table); ASSERT_SORTED(ReverseST0Table);
@@ -535,10 +525,7 @@ void FPS::handleTwoArgFP(MachineBasicBlock::iterator &I) {
MachineInstr *MI = I;
unsigned NumOperands = MI->getNumOperands();
- bool isCompare = MI->getOpcode() == X86::FpUCOM ||
- MI->getOpcode() == X86::FpUCOMI;
- assert((NumOperands == 3 || (NumOperands == 2 && isCompare)) &&
- "Illegal TwoArgFP instruction!");
+ assert(NumOperands == 3 && "Illegal TwoArgFP instruction!");
unsigned Dest = getFPReg(MI->getOperand(0));
unsigned Op0 = getFPReg(MI->getOperand(NumOperands-2));
unsigned Op1 = getFPReg(MI->getOperand(NumOperands-1));
@@ -550,11 +537,6 @@ void FPS::handleTwoArgFP(MachineBasicBlock::iterator &I) {
KillsOp1 |= (KI->second == X86::FP0+Op1);
}
- // If this is an FpUCOM instruction, we must make sure the first operand is on
- // the top of stack, the other one can be anywhere...
- if (isCompare)
- moveToTop(Op0, I);
-
unsigned TOS = getStackEntry(0);
// One of our operands must be on the top of the stack. If neither is yet, we
@@ -579,7 +561,7 @@ void FPS::handleTwoArgFP(MachineBasicBlock::iterator &I) {
Op0 = TOS = Dest;
KillsOp0 = true;
}
- } else if (!KillsOp0 && !KillsOp1 && !isCompare) {
+ } else if (!KillsOp0 && !KillsOp1) {
// If we DO have one of our operands at the top of the stack, but we don't
// have a dead operand, we must duplicate one of the operands to a new slot
// on the stack.
@@ -590,8 +572,7 @@ void FPS::handleTwoArgFP(MachineBasicBlock::iterator &I) {
// Now we know that one of our operands is on the top of the stack, and at
// least one of our operands is killed by this instruction.
- assert((TOS == Op0 || TOS == Op1) &&
- (KillsOp0 || KillsOp1 || isCompare) &&
+ assert((TOS == Op0 || TOS == Op1) && (KillsOp0 || KillsOp1) &&
"Stack conditions not set up right!");
// We decide which form to use based on what is on the top of the stack, and
@@ -628,22 +609,47 @@ void FPS::handleTwoArgFP(MachineBasicBlock::iterator &I) {
popStackAfter(I); // Pop the top of stack
}
- // Insert an explicit pop of the "updated" operand for FUCOM
- if (isCompare) {
- if (KillsOp0 && !KillsOp1)
- popStackAfter(I); // If we kill the first operand, pop it!
- else if (KillsOp1 && Op0 != Op1)
- freeStackSlotAfter(I, Op1);
- }
-
// Update stack information so that we know the destination register is now on
// the stack.
- if (!isCompare) {
- unsigned UpdatedSlot = getSlot(updateST0 ? TOS : NotTOS);
- assert(UpdatedSlot < StackTop && Dest < 7);
- Stack[UpdatedSlot] = Dest;
- RegMap[Dest] = UpdatedSlot;
+ unsigned UpdatedSlot = getSlot(updateST0 ? TOS : NotTOS);
+ assert(UpdatedSlot < StackTop && Dest < 7);
+ Stack[UpdatedSlot] = Dest;
+ RegMap[Dest] = UpdatedSlot;
+ delete MI; // Remove the old instruction
+}
+
+/// handleCompareFP - Handle FpUCOM and FpUCOMI instructions, which have two FP
+/// register arguments and no explicit destinations.
+///
+void FPS::handleCompareFP(MachineBasicBlock::iterator &I) {
+ ASSERT_SORTED(ForwardST0Table); ASSERT_SORTED(ReverseST0Table);
+ ASSERT_SORTED(ForwardSTiTable); ASSERT_SORTED(ReverseSTiTable);
+ MachineInstr *MI = I;
+
+ unsigned NumOperands = MI->getNumOperands();
+ assert(NumOperands == 2 && "Illegal FpUCOM* instruction!");
+ unsigned Op0 = getFPReg(MI->getOperand(NumOperands-2));
+ unsigned Op1 = getFPReg(MI->getOperand(NumOperands-1));
+ bool KillsOp0 = false, KillsOp1 = false;
+
+ for (LiveVariables::killed_iterator KI = LV->killed_begin(MI),
+ E = LV->killed_end(MI); KI != E; ++KI) {
+ KillsOp0 |= (KI->second == X86::FP0+Op0);
+ KillsOp1 |= (KI->second == X86::FP0+Op1);
}
+
+ // Make sure the first operand is on the top of stack, the other one can be
+ // anywhere.
+ moveToTop(Op0, I);
+
+ // Replace the old instruction with a new instruction
+ MBB->remove(I++);
+ unsigned Opcode = MI->getOpcode() == X86::FpUCOM ? X86::FUCOMr : X86::FUCOMIr;
+ I = BuildMI(*MBB, I, Opcode, 1).addReg(getSTReg(Op1));
+
+ // If any of the operands are killed by this instruction, free them.
+ if (KillsOp0) freeStackSlotAfter(I, Op0);
+ if (KillsOp1 && Op0 != Op1) freeStackSlotAfter(I, Op1);
delete MI; // Remove the old instruction
}
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