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| author | Alkis Evlogimenos <alkis@evlogimenos.com> | 2004-07-31 09:38:47 +0000 |
|---|---|---|
| committer | Alkis Evlogimenos <alkis@evlogimenos.com> | 2004-07-31 09:38:47 +0000 |
| commit | 36f506eddb25d5198240a1e3fabcb0912111c7ee (patch) | |
| tree | f4eaa025087176e241ba4aa2663994ba4e3d1a83 /lib/Target/X86 | |
| parent | e4d32f6cf96566f8d37e50212e4f67330150ee20 (diff) | |
| download | external_llvm-36f506eddb25d5198240a1e3fabcb0912111c7ee.zip external_llvm-36f506eddb25d5198240a1e3fabcb0912111c7ee.tar.gz external_llvm-36f506eddb25d5198240a1e3fabcb0912111c7ee.tar.bz2 | |
Implement insertGoto and reverseBranchCondition for the X86.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@15362 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Target/X86')
| -rw-r--r-- | lib/Target/X86/X86InstrInfo.cpp | 33 | ||||
| -rw-r--r-- | lib/Target/X86/X86InstrInfo.h | 10 |
2 files changed, 43 insertions, 0 deletions
diff --git a/lib/Target/X86/X86InstrInfo.cpp b/lib/Target/X86/X86InstrInfo.cpp index f934093..5f5d0b3 100644 --- a/lib/Target/X86/X86InstrInfo.cpp +++ b/lib/Target/X86/X86InstrInfo.cpp @@ -38,3 +38,36 @@ bool X86InstrInfo::isMoveInstr(const MachineInstr& MI, } return false; } + +void X86InstrInfo::insertGoto(MachineBasicBlock& MBB, + MachineBasicBlock& TMBB) const { + BuildMI(MBB, MBB.end(), X86::JMP, 1).addMBB(&TMBB); +} + +MachineBasicBlock::iterator +X86InstrInfo::reverseBranchCondition(MachineBasicBlock::iterator MI) const { + unsigned Opcode = MI->getOpcode(); + assert(isBranch(Opcode) && "MachineInstr must be a branch"); + unsigned ROpcode; + switch (Opcode) { + case X86::JB: ROpcode = X86::JAE; + case X86::JAE: ROpcode = X86::JB; + case X86::JE: ROpcode = X86::JNE; + case X86::JNE: ROpcode = X86::JE; + case X86::JBE: ROpcode = X86::JA; + case X86::JA: ROpcode = X86::JBE; + case X86::JS: ROpcode = X86::JNS; + case X86::JNS: ROpcode = X86::JS; + case X86::JL: ROpcode = X86::JGE; + case X86::JGE: ROpcode = X86::JL; + case X86::JLE: ROpcode = X86::JG; + case X86::JG: ROpcode = X86::JLE; + default: + assert(0 && "Cannot reverse uncodnitional branches!"); + } + MachineBasicBlock* MBB = MI->getParent(); + MachineBasicBlock* TMBB = MI->getOperand(0).getMachineBasicBlock(); + MachineInstrBuilder IB = BuildMI(*MBB, MBB->erase(MI), ROpcode, 1); + IB.addMBB(TMBB); + return IB; +} diff --git a/lib/Target/X86/X86InstrInfo.h b/lib/Target/X86/X86InstrInfo.h index 5b3ddd0..eb920d6 100644 --- a/lib/Target/X86/X86InstrInfo.h +++ b/lib/Target/X86/X86InstrInfo.h @@ -203,6 +203,16 @@ public: unsigned& sourceReg, unsigned& destReg) const; + /// Insert a goto (unconditional branch) sequence to TMBB, at the + /// end of MBB + virtual void insertGoto(MachineBasicBlock& MBB, + MachineBasicBlock& TMBB) const; + + /// Reverses the branch condition of the MachineInstr pointed by + /// MI. The instruction is replaced and the new MI is returned. + virtual MachineBasicBlock::iterator + reverseBranchCondition(MachineBasicBlock::iterator MI) const; + // getBaseOpcodeFor - This function returns the "base" X86 opcode for the // specified opcode number. // |