From 8496a26113859288730d0d97637d032de53b2a7e Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Wed, 10 Feb 2010 06:30:00 +0000 Subject: [PATCH] simplify displacement handling, emit displacements by-operand even for the immediate case. No functionality change. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95770 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Target/X86/X86MCCodeEmitter.cpp | 69 ++++++++--------------------- 1 file changed, 19 insertions(+), 50 deletions(-) diff --git a/lib/Target/X86/X86MCCodeEmitter.cpp b/lib/Target/X86/X86MCCodeEmitter.cpp index 679abb388c4..f55ef77cc3a 100644 --- a/lib/Target/X86/X86MCCodeEmitter.cpp +++ b/lib/Target/X86/X86MCCodeEmitter.cpp @@ -68,8 +68,8 @@ public: } } - void EmitDisplacementField(const MCOperand *RelocOp, int DispVal, - int64_t Adj, bool IsPCRel, raw_ostream &OS) const; + void EmitDisplacementField(const MCOperand &Disp, int64_t Adj, bool IsPCRel, + raw_ostream &OS) const; inline static unsigned char ModRMByte(unsigned Mod, unsigned RegOpcode, unsigned RM) { @@ -119,12 +119,12 @@ static bool isDisp8(int Value) { } void X86MCCodeEmitter:: -EmitDisplacementField(const MCOperand *RelocOp, int DispVal, - int64_t Adj, bool IsPCRel, raw_ostream &OS) const { +EmitDisplacementField(const MCOperand &DispOp, int64_t Adj, bool IsPCRel, + raw_ostream &OS) const { // If this is a simple integer displacement that doesn't require a relocation, // emit it now. - if (!RelocOp) { - EmitConstant(DispVal, 4, OS); + if (DispOp.isImm()) { + EmitConstant(DispOp.getImm(), 4, OS); return; } @@ -159,39 +159,8 @@ EmitDisplacementField(const MCOperand *RelocOp, int DispVal, void X86MCCodeEmitter::EmitMemModRMByte(const MCInst &MI, unsigned Op, unsigned RegOpcodeField, - intptr_t PCAdj, - raw_ostream &OS) const { - const MCOperand &Op3 = MI.getOperand(Op+3); - int DispVal = 0; - const MCOperand *DispForReloc = 0; - - // Figure out what sort of displacement we have to handle here. - if (Op3.isImm()) { - DispVal = Op3.getImm(); - } else { - assert(0 && "relocatable operand"); -#if 0 - if (Op3.isGlobal()) { - DispForReloc = &Op3; - } else if (Op3.isSymbol()) { - DispForReloc = &Op3; - } else if (Op3.isCPI()) { - if (!MCE.earlyResolveAddresses() || Is64BitMode || IsPIC) { - DispForReloc = &Op3; - } else { - DispVal += MCE.getConstantPoolEntryAddress(Op3.getIndex()); - DispVal += Op3.getOffset(); - } - } else { - assert(Op3.isJTI()); - if (!MCE.earlyResolveAddresses() || Is64BitMode || IsPIC) { - DispForReloc = &Op3; - } else { - DispVal += MCE.getJumpTableEntryAddress(Op3.getIndex()); - } -#endif - } - + intptr_t PCAdj, raw_ostream &OS) const { + const MCOperand &Disp = MI.getOperand(Op+3); const MCOperand &Base = MI.getOperand(Op); const MCOperand &Scale = MI.getOperand(Op+1); const MCOperand &IndexReg = MI.getOperand(Op+2); @@ -215,7 +184,7 @@ void X86MCCodeEmitter::EmitMemModRMByte(const MCInst &MI, unsigned Op, if (BaseReg == 0 || // [disp32] in X86-32 mode BaseReg == X86::RIP) { // [disp32+RIP] in X86-64 mode EmitByte(ModRMByte(0, RegOpcodeField, 5), OS); - EmitDisplacementField(DispForReloc, DispVal, PCAdj, true, OS); + EmitDisplacementField(Disp, PCAdj, true, OS); return; } @@ -225,21 +194,21 @@ void X86MCCodeEmitter::EmitMemModRMByte(const MCInst &MI, unsigned Op, // indirect register encoding, this handles addresses like [EAX]. The // encoding for [EBP] with no displacement means [disp32] so we handle it // by emitting a displacement of 0 below. - if (!DispForReloc && DispVal == 0 && BaseRegNo != N86::EBP) { + if (Disp.isImm() && Disp.getImm() == 0 && BaseRegNo != N86::EBP) { EmitByte(ModRMByte(0, RegOpcodeField, BaseRegNo), OS); return; } // Otherwise, if the displacement fits in a byte, encode as [REG+disp8]. - if (!DispForReloc && isDisp8(DispVal)) { + if (Disp.isImm() && isDisp8(Disp.getImm())) { EmitByte(ModRMByte(1, RegOpcodeField, BaseRegNo), OS); - EmitConstant(DispVal, 1, OS); + EmitConstant(Disp.getImm(), 1, OS); return; } // Otherwise, emit the most general non-SIB encoding: [REG+disp32] EmitByte(ModRMByte(2, RegOpcodeField, BaseRegNo), OS); - EmitDisplacementField(DispForReloc, DispVal, PCAdj, IsPCRel, OS); + EmitDisplacementField(Disp, PCAdj, IsPCRel, OS); return; } @@ -254,14 +223,14 @@ void X86MCCodeEmitter::EmitMemModRMByte(const MCInst &MI, unsigned Op, // MOD=0, BASE=5, to JUST get the index, scale, and displacement. EmitByte(ModRMByte(0, RegOpcodeField, 4), OS); ForceDisp32 = true; - } else if (DispForReloc) { + } else if (!Disp.isImm()) { // Emit the normal disp32 encoding. EmitByte(ModRMByte(2, RegOpcodeField, 4), OS); ForceDisp32 = true; - } else if (DispVal == 0 && BaseReg != X86::EBP) { + } else if (Disp.getImm() == 0 && BaseReg != X86::EBP) { // Emit no displacement ModR/M byte EmitByte(ModRMByte(0, RegOpcodeField, 4), OS); - } else if (isDisp8(DispVal)) { + } else if (isDisp8(Disp.getImm())) { // Emit the disp8 encoding. EmitByte(ModRMByte(1, RegOpcodeField, 4), OS); ForceDisp8 = true; // Make sure to force 8 bit disp if Base=EBP @@ -294,9 +263,9 @@ void X86MCCodeEmitter::EmitMemModRMByte(const MCInst &MI, unsigned Op, // Do we need to output a displacement? if (ForceDisp8) - EmitConstant(DispVal, 1, OS); - else if (DispVal != 0 || ForceDisp32) - EmitDisplacementField(DispForReloc, DispVal, PCAdj, IsPCRel, OS); + EmitConstant(Disp.getImm(), 1, OS); + else if (ForceDisp32 || Disp.getImm() != 0) + EmitDisplacementField(Disp, PCAdj, IsPCRel, OS); } /// DetermineREXPrefix - Determine if the MCInst has to be encoded with a X86-64 -- 2.34.1