diff options
Diffstat (limited to 'lib/Target/X86/X86FloatingPoint.cpp')
| -rw-r--r-- | lib/Target/X86/X86FloatingPoint.cpp | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/lib/Target/X86/X86FloatingPoint.cpp b/lib/Target/X86/X86FloatingPoint.cpp index 6f619a9..a9b6fdd 100644 --- a/lib/Target/X86/X86FloatingPoint.cpp +++ b/lib/Target/X86/X86FloatingPoint.cpp @@ -260,6 +260,21 @@ namespace { BuildMI(*MBB, I, dl, TII->get(X86::LD_Frr)).addReg(STReg); } + /// duplicatePendingSTBeforeKill - The instruction at I is about to kill + /// RegNo. If any PendingST registers still need the RegNo value, duplicate + /// them to new scratch registers. + void duplicatePendingSTBeforeKill(unsigned RegNo, MachineInstr *I) { + for (unsigned i = 0; i != NumPendingSTs; ++i) { + if (PendingST[i] != RegNo) + continue; + unsigned SR = getScratchReg(); + DEBUG(dbgs() << "Duplicating pending ST" << i + << " in FP" << RegNo << " to FP" << SR << '\n'); + duplicateToTop(RegNo, SR, I); + PendingST[i] = SR; + } + } + /// popStackAfter - Pop the current value off of the top of the FP stack /// after the specified instruction. void popStackAfter(MachineBasicBlock::iterator &I); @@ -973,6 +988,9 @@ void FPS::handleOneArgFP(MachineBasicBlock::iterator &I) { unsigned Reg = getFPReg(MI->getOperand(NumOps-1)); bool KillsSrc = MI->killsRegister(X86::FP0+Reg); + if (KillsSrc) + duplicatePendingSTBeforeKill(Reg, I); + // FISTP64m is strange because there isn't a non-popping versions. // If we have one _and_ we don't want to pop the operand, duplicate the value // on the stack instead of moving it. This ensure that popping the value is @@ -1036,6 +1054,7 @@ void FPS::handleOneArgFPRW(MachineBasicBlock::iterator &I) { bool KillsSrc = MI->killsRegister(X86::FP0+Reg); if (KillsSrc) { + duplicatePendingSTBeforeKill(Reg, I); // If this is the last use of the source register, just make sure it's on // the top of the stack. moveToTop(Reg, I); @@ -1322,6 +1341,7 @@ void FPS::handleSpecialFP(MachineBasicBlock::iterator &I) { // When the source is killed, allocate a scratch FP register. if (KillsSrc) { + duplicatePendingSTBeforeKill(SrcFP, I); unsigned Slot = getSlot(SrcFP); unsigned SR = getScratchReg(); PendingST[DstST] = SR; |