[llvm-commits] CVS: llvm/lib/Target/X86/X86CodeEmitter.cpp
Chris Lattner
lattner at cs.uiuc.edu
Thu Oct 14 21:53:24 PDT 2004
Changes in directory llvm/lib/Target/X86:
X86CodeEmitter.cpp updated: 1.65 -> 1.66
---
Log message:
Give the X86 JIT the ability to encode global+disp constants. Patch
contributed by Jeff Cohen!
---
Diffs of the changes: (+54 -27)
Index: llvm/lib/Target/X86/X86CodeEmitter.cpp
diff -u llvm/lib/Target/X86/X86CodeEmitter.cpp:1.65 llvm/lib/Target/X86/X86CodeEmitter.cpp:1.66
--- llvm/lib/Target/X86/X86CodeEmitter.cpp:1.65 Sun Sep 12 16:26:04 2004
+++ llvm/lib/Target/X86/X86CodeEmitter.cpp Thu Oct 14 23:53:13 2004
@@ -193,7 +193,7 @@
void emitPCRelativeBlockAddress(const MachineBasicBlock *BB);
void emitMaybePCRelativeValue(unsigned Address, bool isPCRelative);
void emitGlobalAddressForCall(GlobalValue *GV);
- void emitGlobalAddressForPtr(GlobalValue *GV);
+ void emitGlobalAddressForPtr(GlobalValue *GV, int Disp = 0);
void emitRegModRMByte(unsigned ModRMReg, unsigned RegOpcodeField);
void emitSIBByte(unsigned SS, unsigned Index, unsigned Base);
@@ -294,7 +294,7 @@
/// this is part of a "take the address of a global" instruction, which is not
/// PC relative.
///
-void Emitter::emitGlobalAddressForPtr(GlobalValue *GV) {
+void Emitter::emitGlobalAddressForPtr(GlobalValue *GV, int Disp /* = 0 */) {
// Get the address from the backend...
unsigned Address = MCE.getGlobalValueAddress(GV);
@@ -306,7 +306,7 @@
Address = getResolver(MCE).getLazyResolver((Function*)GV);
}
- emitMaybePCRelativeValue(Address, false);
+ emitMaybePCRelativeValue(Address + Disp, false);
}
@@ -374,14 +374,25 @@
void Emitter::emitMemModRMByte(const MachineInstr &MI,
unsigned Op, unsigned RegOpcodeField) {
- const MachineOperand &Disp = MI.getOperand(Op+3);
+ const MachineOperand &Op3 = MI.getOperand(Op+3);
+ GlobalValue *GV = 0;
+ int DispVal = 0;
+
+ if (Op3.isGlobalAddress()) {
+ GV = Op3.getGlobal();
+ DispVal = Op3.getOffset();
+ } else {
+ DispVal = Op3.getImmedValue();
+ }
+
if (MI.getOperand(Op).isConstantPoolIndex()) {
// Emit a direct address reference [disp32] where the displacement of the
// constant pool entry is controlled by the MCE.
+ assert(!GV && "Constant Pool reference cannot be relative to global!");
MCE.emitByte(ModRMByte(0, RegOpcodeField, 5));
unsigned Index = MI.getOperand(Op).getConstantPoolIndex();
unsigned Address = MCE.getConstantPoolEntryAddress(Index);
- MCE.emitWord(Address+Disp.getImmedValue());
+ MCE.emitWord(Address+DispVal);
return;
}
@@ -394,20 +405,27 @@
if (BaseReg.getReg() == 0) { // Just a displacement?
// Emit special case [disp32] encoding
MCE.emitByte(ModRMByte(0, RegOpcodeField, 5));
- emitConstant(Disp.getImmedValue(), 4);
+ if (GV)
+ emitGlobalAddressForPtr(GV, DispVal);
+ else
+ emitConstant(DispVal, 4);
} else {
unsigned BaseRegNo = getX86RegNum(BaseReg.getReg());
- if (Disp.getImmedValue() == 0 && BaseRegNo != N86::EBP) {
+ if (GV) {
+ // Emit the most general non-SIB encoding: [REG+disp32]
+ MCE.emitByte(ModRMByte(2, RegOpcodeField, BaseRegNo));
+ emitGlobalAddressForPtr(GV, DispVal);
+ } else if (DispVal == 0 && BaseRegNo != N86::EBP) {
// Emit simple indirect register encoding... [EAX] f.e.
MCE.emitByte(ModRMByte(0, RegOpcodeField, BaseRegNo));
- } else if (isDisp8(Disp.getImmedValue())) {
+ } else if (isDisp8(DispVal)) {
// Emit the disp8 encoding... [REG+disp8]
MCE.emitByte(ModRMByte(1, RegOpcodeField, BaseRegNo));
- emitConstant(Disp.getImmedValue(), 1);
+ emitConstant(DispVal, 1);
} else {
// Emit the most general non-SIB encoding: [REG+disp32]
MCE.emitByte(ModRMByte(2, RegOpcodeField, BaseRegNo));
- emitConstant(Disp.getImmedValue(), 4);
+ emitConstant(DispVal, 4);
}
}
@@ -421,10 +439,14 @@
// MOD=0, BASE=5, to JUST get the index, scale, and displacement.
MCE.emitByte(ModRMByte(0, RegOpcodeField, 4));
ForceDisp32 = true;
- } else if (Disp.getImmedValue() == 0 && BaseReg.getReg() != X86::EBP) {
+ } else if (GV) {
+ // Emit the normal disp32 encoding...
+ MCE.emitByte(ModRMByte(2, RegOpcodeField, 4));
+ ForceDisp32 = true;
+ } else if (DispVal == 0 && BaseReg.getReg() != X86::EBP) {
// Emit no displacement ModR/M byte
MCE.emitByte(ModRMByte(0, RegOpcodeField, 4));
- } else if (isDisp8(Disp.getImmedValue())) {
+ } else if (isDisp8(DispVal)) {
// Emit the disp8 encoding...
MCE.emitByte(ModRMByte(1, RegOpcodeField, 4));
ForceDisp8 = true; // Make sure to force 8 bit disp if Base=EBP
@@ -446,18 +468,20 @@
unsigned BaseRegNo = getX86RegNum(BaseReg.getReg());
unsigned IndexRegNo;
if (IndexReg.getReg())
- IndexRegNo = getX86RegNum(IndexReg.getReg());
+ IndexRegNo = getX86RegNum(IndexReg.getReg());
else
- IndexRegNo = 4; // For example [ESP+1*<noreg>+4]
+ IndexRegNo = 4; // For example [ESP+1*<noreg>+4]
emitSIBByte(SS, IndexRegNo, BaseRegNo);
}
// Do we need to output a displacement?
- if (Disp.getImmedValue() != 0 || ForceDisp32 || ForceDisp8) {
- if (!ForceDisp32 && isDisp8(Disp.getImmedValue()))
- emitConstant(Disp.getImmedValue(), 1);
+ if (DispVal != 0 || ForceDisp32 || ForceDisp8) {
+ if (!ForceDisp32 && isDisp8(DispVal))
+ emitConstant(DispVal, 1);
+ else if (GV)
+ emitGlobalAddressForPtr(GV, DispVal);
else
- emitConstant(Disp.getImmedValue(), 4);
+ emitConstant(DispVal, 4);
}
}
}
@@ -492,8 +516,8 @@
case X86II::D8: case X86II::D9: case X86II::DA: case X86II::DB:
case X86II::DC: case X86II::DD: case X86II::DE: case X86II::DF:
MCE.emitByte(0xD8+
- (((Desc.TSFlags & X86II::Op0Mask)-X86II::D8)
- >> X86II::Op0Shift));
+ (((Desc.TSFlags & X86II::Op0Mask)-X86II::D8)
+ >> X86II::Op0Shift));
break; // Two-byte opcode prefix
default: assert(0 && "Invalid prefix!");
case 0: break; // No prefix!
@@ -525,7 +549,7 @@
} else if (MO.isImmediate()) {
emitConstant(MO.getImmedValue(), sizeOfImm(Desc));
} else {
- assert(0 && "Unknown RawFrm operand!");
+ assert(0 && "Unknown RawFrm operand!");
}
}
break;
@@ -535,15 +559,17 @@
if (MI.getNumOperands() == 2) {
const MachineOperand &MO1 = MI.getOperand(1);
if (Value *V = MO1.getVRegValueOrNull()) {
- assert(sizeOfImm(Desc) == 4 && "Don't know how to emit non-pointer values!");
+ assert(sizeOfImm(Desc) == 4 &&
+ "Don't know how to emit non-pointer values!");
emitGlobalAddressForPtr(cast<GlobalValue>(V));
} else if (MO1.isGlobalAddress()) {
- assert(sizeOfImm(Desc) == 4 && "Don't know how to emit non-pointer values!");
+ assert(sizeOfImm(Desc) == 4 &&
+ "Don't know how to emit non-pointer values!");
assert(!MO1.isPCRelative() && "Function pointer ref is PC relative?");
- emitGlobalAddressForPtr(MO1.getGlobal());
+ emitGlobalAddressForPtr(MO1.getGlobal(), MO1.getOffset());
} else if (MO1.isExternalSymbol()) {
- assert(sizeOfImm(Desc) == 4 && "Don't know how to emit non-pointer values!");
-
+ assert(sizeOfImm(Desc) == 4 &&
+ "Don't know how to emit non-pointer values!");
unsigned Address = MCE.getGlobalValueAddress(MO1.getSymbolName());
assert(Address && "Unknown external symbol!");
emitMaybePCRelativeValue(Address, MO1.isPCRelative());
@@ -608,7 +634,8 @@
if (MI.getOperand(4).isImmediate())
emitConstant(MI.getOperand(4).getImmedValue(), sizeOfImm(Desc));
else if (MI.getOperand(4).isGlobalAddress())
- emitGlobalAddressForPtr(MI.getOperand(4).getGlobal());
+ emitGlobalAddressForPtr(MI.getOperand(4).getGlobal(),
+ MI.getOperand(4).getOffset());
else
assert(0 && "Unknown operand!");
}
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