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[BOLT] Add createCondBranch() and createLongUncondBranch() #85315

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Merged
merged 1 commit into from
Mar 14, 2024
Merged

[BOLT] Add createCondBranch() and createLongUncondBranch() #85315

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13 changes: 13 additions & 0 deletions bolt/include/bolt/Core/MCPlusBuilder.h
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Original file line number Diff line number Diff line change
Expand Up @@ -1558,6 +1558,13 @@ class MCPlusBuilder {
llvm_unreachable("not implemented");
}

/// Create a version of unconditional jump that has the largest span for a
/// single instruction with direct target.
virtual void createLongUncondBranch(MCInst &Inst, const MCSymbol *Target,
MCContext *Ctx) const {
llvm_unreachable("not implemented");
}

/// Creates a new call instruction in Inst and sets its operand to
/// Target.
virtual void createCall(MCInst &Inst, const MCSymbol *Target,
Expand Down Expand Up @@ -1675,6 +1682,12 @@ class MCPlusBuilder {
return Inst.getOpcode() == TargetOpcode::CFI_INSTRUCTION;
}

/// Create a conditional branch with a target-specific conditional code \p CC.
virtual void createCondBranch(MCInst &Inst, const MCSymbol *Target,
unsigned CC, MCContext *Ctx) const {
llvm_unreachable("not implemented");
}

/// Reverses the branch condition in Inst and update its taken target to TBB.
///
/// Returns true on success.
Expand Down
17 changes: 17 additions & 0 deletions bolt/lib/Target/X86/X86MCPlusBuilder.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -2734,6 +2734,14 @@ class X86MCPlusBuilder : public MCPlusBuilder {
MCSymbolRefExpr::create(TBB, MCSymbolRefExpr::VK_None, *Ctx)));
}

void createLongUncondBranch(MCInst &Inst, const MCSymbol *Target,
MCContext *Ctx) const override {
Inst.setOpcode(X86::JMP_4);
Inst.clear();
Inst.addOperand(MCOperand::createExpr(
MCSymbolRefExpr::create(Target, MCSymbolRefExpr::VK_None, *Ctx)));
}

void createCall(MCInst &Inst, const MCSymbol *Target,
MCContext *Ctx) override {
Inst.setOpcode(X86::CALL64pcrel32);
Expand All @@ -2759,6 +2767,15 @@ class X86MCPlusBuilder : public MCPlusBuilder {
Inst.setOpcode(X86::TRAP);
}

void createCondBranch(MCInst &Inst, const MCSymbol *Target, unsigned CC,
MCContext *Ctx) const override {
Inst.setOpcode(X86::JCC_1);
Inst.clear();
Inst.addOperand(MCOperand::createExpr(
MCSymbolRefExpr::create(Target, MCSymbolRefExpr::VK_None, *Ctx)));
Inst.addOperand(MCOperand::createImm(CC));
}

bool reverseBranchCondition(MCInst &Inst, const MCSymbol *TBB,
MCContext *Ctx) const override {
unsigned InvCC = getInvertedCondCode(getCondCode(Inst));
Expand Down