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| author | Nate Begeman <natebegeman@mac.com> | 2004-09-29 05:00:31 +0000 |
|---|---|---|
| committer | Nate Begeman <natebegeman@mac.com> | 2004-09-29 05:00:31 +0000 |
| commit | 2f1d0ae95e9d53684dfe2c48e90eeeef394a5029 (patch) | |
| tree | 6695b13b1d9311e455cacb9cddef812eb197baf8 /llvm/lib/Target/PowerPC | |
| parent | c44da15813c19d10f6b3156d8849d75c271415d4 (diff) | |
| download | bcm5719-llvm-2f1d0ae95e9d53684dfe2c48e90eeeef394a5029.tar.gz bcm5719-llvm-2f1d0ae95e9d53684dfe2c48e90eeeef394a5029.zip | |
Generate better code by being far less clever when it comes to the select instruction. Don't create overlapping register lifetimes
llvm-svn: 16580
Diffstat (limited to 'llvm/lib/Target/PowerPC')
| -rw-r--r-- | llvm/lib/Target/PowerPC/PPC32ISelSimple.cpp | 24 |
1 files changed, 17 insertions, 7 deletions
diff --git a/llvm/lib/Target/PowerPC/PPC32ISelSimple.cpp b/llvm/lib/Target/PowerPC/PPC32ISelSimple.cpp index 9f1229a53b2..c273e8fb314 100644 --- a/llvm/lib/Target/PowerPC/PPC32ISelSimple.cpp +++ b/llvm/lib/Target/PowerPC/PPC32ISelSimple.cpp @@ -1296,7 +1296,6 @@ void PPC32ISel::emitSelectOperation(MachineBasicBlock *MBB, BuildMI(*MBB, IP, PPC::CMPWI, 2, PPC::CR0).addReg(CondReg).addSImm(0); Opcode = getPPCOpcodeForSetCCNumber(Instruction::SetNE); } - unsigned TrueValue = getReg(TrueVal, BB, BB->end()); MachineBasicBlock *thisMBB = BB; const BasicBlock *LLVM_BB = BB->getBasicBlock(); @@ -1306,22 +1305,33 @@ void PPC32ISel::emitSelectOperation(MachineBasicBlock *MBB, // thisMBB: // ... // cmpTY cr0, r1, r2 - // %TrueValue = ... - // bCC sinkMBB + // bCC copy1MBB + // fallthrough --> copy0MBB MachineBasicBlock *copy0MBB = new MachineBasicBlock(LLVM_BB); + MachineBasicBlock *copy1MBB = new MachineBasicBlock(LLVM_BB); MachineBasicBlock *sinkMBB = new MachineBasicBlock(LLVM_BB); - BuildMI(BB, Opcode, 2).addReg(PPC::CR0).addMBB(sinkMBB); + BuildMI(BB, Opcode, 2).addReg(PPC::CR0).addMBB(copy1MBB); F->getBasicBlockList().insert(It, copy0MBB); + F->getBasicBlockList().insert(It, copy1MBB); F->getBasicBlockList().insert(It, sinkMBB); // Update machine-CFG edges BB->addSuccessor(copy0MBB); - BB->addSuccessor(sinkMBB); + BB->addSuccessor(copy1MBB); // copy0MBB: // %FalseValue = ... - // fallthrough + // b sinkMBB BB = copy0MBB; unsigned FalseValue = getReg(FalseVal, BB, BB->begin()); + BuildMI(BB, PPC::B, 1).addMBB(sinkMBB); + // Update machine-CFG edges + BB->addSuccessor(sinkMBB); + + // copy1MBB: + // %TrueValue = ... + // fallthrough + BB = copy1MBB; + unsigned TrueValue = getReg(TrueVal, BB, BB->begin()); // Update machine-CFG edges BB->addSuccessor(sinkMBB); @@ -1330,7 +1340,7 @@ void PPC32ISel::emitSelectOperation(MachineBasicBlock *MBB, // ... BB = sinkMBB; BuildMI(BB, PPC::PHI, 4, DestReg).addReg(FalseValue) - .addMBB(copy0MBB).addReg(TrueValue).addMBB(thisMBB); + .addMBB(copy0MBB).addReg(TrueValue).addMBB(copy1MBB); // For a register pair representing a long value, define the second reg // FIXME: Can this really be correct for selecting longs? |
