diff options
Diffstat (limited to 'llvm/lib/Target/X86')
| -rw-r--r-- | llvm/lib/Target/X86/X86InstrInfo.cpp | 16 | ||||
| -rw-r--r-- | llvm/lib/Target/X86/X86InstrInfo.h | 2 |
2 files changed, 18 insertions, 0 deletions
diff --git a/llvm/lib/Target/X86/X86InstrInfo.cpp b/llvm/lib/Target/X86/X86InstrInfo.cpp index 68c5ff44ca9..12de514a3d3 100644 --- a/llvm/lib/Target/X86/X86InstrInfo.cpp +++ b/llvm/lib/Target/X86/X86InstrInfo.cpp @@ -5477,16 +5477,32 @@ void X86InstrInfo::getNoopForMachoTarget(MCInst &NopInst) const { NopInst.setOpcode(X86::NOOP); } +// This code must remain in sync with getJumpInstrTableEntryBound in this class! +// In particular, getJumpInstrTableEntryBound must always return an upper bound +// on the encoding lengths of the instructions generated by +// getUnconditionalBranch and getTrap. void X86InstrInfo::getUnconditionalBranch( MCInst &Branch, const MCSymbolRefExpr *BranchTarget) const { Branch.setOpcode(X86::JMP_4); Branch.addOperand(MCOperand::CreateExpr(BranchTarget)); } +// This code must remain in sync with getJumpInstrTableEntryBound in this class! +// In particular, getJumpInstrTableEntryBound must always return an upper bound +// on the encoding lengths of the instructions generated by +// getUnconditionalBranch and getTrap. void X86InstrInfo::getTrap(MCInst &MI) const { MI.setOpcode(X86::TRAP); } +// See getTrap and getUnconditionalBranch for conditions on the value returned +// by this function. +unsigned X86InstrInfo::getJumpInstrTableEntryBound() const { + // 5 bytes suffice: JMP_4 Symbol@PLT is uses 1 byte (E9) for the JMP_4 and 4 + // bytes for the symbol offset. And TRAP is ud2, which is two bytes (0F 0B). + return 5; +} + bool X86InstrInfo::isHighLatencyDef(int opc) const { switch (opc) { default: return false; diff --git a/llvm/lib/Target/X86/X86InstrInfo.h b/llvm/lib/Target/X86/X86InstrInfo.h index f3f54ae5664..57b19589545 100644 --- a/llvm/lib/Target/X86/X86InstrInfo.h +++ b/llvm/lib/Target/X86/X86InstrInfo.h @@ -413,6 +413,8 @@ public: void getTrap(MCInst &MI) const override; + unsigned getJumpInstrTableEntryBound() const override; + bool isHighLatencyDef(int opc) const override; bool hasHighOperandLatency(const InstrItineraryData *ItinData, |
