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-rw-r--r--lib/Target/X86/X86MCCodeEmitter.cpp99
1 files changed, 82 insertions, 17 deletions
diff --git a/lib/Target/X86/X86MCCodeEmitter.cpp b/lib/Target/X86/X86MCCodeEmitter.cpp
index 9564fe0..fea37f8 100644
--- a/lib/Target/X86/X86MCCodeEmitter.cpp
+++ b/lib/Target/X86/X86MCCodeEmitter.cpp
@@ -11,13 +11,14 @@
//
//===----------------------------------------------------------------------===//
-#define DEBUG_TYPE "x86-emitter"
+#define DEBUG_TYPE "mccodeemitter"
#include "X86.h"
#include "X86InstrInfo.h"
#include "X86FixupKinds.h"
#include "llvm/MC/MCCodeEmitter.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCInst.h"
+#include "llvm/MC/MCSymbol.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
@@ -38,7 +39,7 @@ public:
~X86MCCodeEmitter() {}
unsigned getNumFixupKinds() const {
- return 5;
+ return 7;
}
const MCFixupKindInfo &getFixupKindInfo(MCFixupKind Kind) const {
@@ -47,7 +48,9 @@ public:
{ "reloc_pcrel_1byte", 0, 1 * 8, MCFixupKindInfo::FKF_IsPCRel },
{ "reloc_pcrel_2byte", 0, 2 * 8, MCFixupKindInfo::FKF_IsPCRel },
{ "reloc_riprel_4byte", 0, 4 * 8, MCFixupKindInfo::FKF_IsPCRel },
- { "reloc_riprel_4byte_movq_load", 0, 4 * 8, MCFixupKindInfo::FKF_IsPCRel }
+ { "reloc_riprel_4byte_movq_load", 0, 4 * 8, MCFixupKindInfo::FKF_IsPCRel },
+ { "reloc_signed_4byte", 0, 4 * 8, 0},
+ { "reloc_global_offset_table", 0, 4 * 8, 0}
};
if (Kind < FirstTargetFixupKind)
@@ -179,6 +182,37 @@ static MCFixupKind getImmFixupKind(uint64_t TSFlags) {
}
}
+/// Is32BitMemOperand - Return true if the specified instruction with a memory
+/// operand should emit the 0x67 prefix byte in 64-bit mode due to a 32-bit
+/// memory operand. Op specifies the operand # of the memoperand.
+static bool Is32BitMemOperand(const MCInst &MI, unsigned Op) {
+ const MCOperand &BaseReg = MI.getOperand(Op+X86::AddrBaseReg);
+ const MCOperand &IndexReg = MI.getOperand(Op+X86::AddrIndexReg);
+
+ if ((BaseReg.getReg() != 0 && X86::GR32RegClass.contains(BaseReg.getReg())) ||
+ (IndexReg.getReg() != 0 && X86::GR32RegClass.contains(IndexReg.getReg())))
+ return true;
+ return false;
+}
+
+/// StartsWithGlobalOffsetTable - Return true for the simple cases where this
+/// expression starts with _GLOBAL_OFFSET_TABLE_. This is a needed to support
+/// PIC on ELF i386 as that symbol is magic. We check only simple case that
+/// are know to be used: _GLOBAL_OFFSET_TABLE_ by itself or at the start
+/// of a binary expression.
+static bool StartsWithGlobalOffsetTable(const MCExpr *Expr) {
+ if (Expr->getKind() == MCExpr::Binary) {
+ const MCBinaryExpr *BE = static_cast<const MCBinaryExpr *>(Expr);
+ Expr = BE->getLHS();
+ }
+
+ if (Expr->getKind() != MCExpr::SymbolRef)
+ return false;
+
+ const MCSymbolRefExpr *Ref = static_cast<const MCSymbolRefExpr*>(Expr);
+ const MCSymbol &S = Ref->getSymbol();
+ return S.getName() == "_GLOBAL_OFFSET_TABLE_";
+}
void X86MCCodeEmitter::
EmitImmediate(const MCOperand &DispOp, unsigned Size, MCFixupKind FixupKind,
@@ -196,6 +230,13 @@ EmitImmediate(const MCOperand &DispOp, unsigned Size, MCFixupKind FixupKind,
// If we have an immoffset, add it to the expression.
const MCExpr *Expr = DispOp.getExpr();
+ if (FixupKind == FK_Data_4 && StartsWithGlobalOffsetTable(Expr)) {
+ assert(ImmOffset == 0);
+
+ FixupKind = MCFixupKind(X86::reloc_global_offset_table);
+ ImmOffset = CurByte;
+ }
+
// If the fixup is pc-relative, we need to bias the value to be relative to
// the start of the field, not the end of the field.
if (FixupKind == MCFixupKind(X86::reloc_pcrel_4byte) ||
@@ -221,10 +262,10 @@ void X86MCCodeEmitter::EmitMemModRMByte(const MCInst &MI, unsigned Op,
uint64_t TSFlags, unsigned &CurByte,
raw_ostream &OS,
SmallVectorImpl<MCFixup> &Fixups) 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);
+ const MCOperand &Disp = MI.getOperand(Op+X86::AddrDisp);
+ const MCOperand &Base = MI.getOperand(Op+X86::AddrBaseReg);
+ const MCOperand &Scale = MI.getOperand(Op+X86::AddrScaleAmt);
+ const MCOperand &IndexReg = MI.getOperand(Op+X86::AddrIndexReg);
unsigned BaseReg = Base.getReg();
// Handle %rip relative addressing.
@@ -238,8 +279,7 @@ void X86MCCodeEmitter::EmitMemModRMByte(const MCInst &MI, unsigned Op,
// movq loads are handled with a special relocation form which allows the
// linker to eliminate some loads for GOT references which end up in the
// same linkage unit.
- if (MI.getOpcode() == X86::MOV64rm ||
- MI.getOpcode() == X86::MOV64rm_TC)
+ if (MI.getOpcode() == X86::MOV64rm)
FixupKind = X86::reloc_riprel_4byte_movq_load;
// rip-relative addressing is actually relative to the *next* instruction.
@@ -295,7 +335,8 @@ void X86MCCodeEmitter::EmitMemModRMByte(const MCInst &MI, unsigned Op,
// Otherwise, emit the most general non-SIB encoding: [REG+disp32]
EmitByte(ModRMByte(2, RegOpcodeField, BaseRegNo), CurByte, OS);
- EmitImmediate(Disp, 4, FK_Data_4, CurByte, OS, Fixups);
+ EmitImmediate(Disp, 4, MCFixupKind(X86::reloc_signed_4byte), CurByte, OS,
+ Fixups);
return;
}
@@ -355,7 +396,8 @@ void X86MCCodeEmitter::EmitMemModRMByte(const MCInst &MI, unsigned Op,
if (ForceDisp8)
EmitImmediate(Disp, 1, FK_Data_1, CurByte, OS, Fixups);
else if (ForceDisp32 || Disp.getImm() != 0)
- EmitImmediate(Disp, 4, FK_Data_4, CurByte, OS, Fixups);
+ EmitImmediate(Disp, 4, MCFixupKind(X86::reloc_signed_4byte), CurByte, OS,
+ Fixups);
}
/// EmitVEXOpcodePrefix - AVX instructions are encoded using a opcode prefix
@@ -708,14 +750,15 @@ void X86MCCodeEmitter::EmitOpcodePrefix(uint64_t TSFlags, unsigned &CurByte,
if ((TSFlags & X86II::Op0Mask) == X86II::REP)
EmitByte(0xF3, CurByte, OS);
+ // Emit the address size opcode prefix as needed.
+ if ((TSFlags & X86II::AdSize) ||
+ (MemOperand != -1 && Is64BitMode && Is32BitMemOperand(MI, MemOperand)))
+ EmitByte(0x67, CurByte, OS);
+
// Emit the operand size opcode prefix as needed.
if (TSFlags & X86II::OpSize)
EmitByte(0x66, CurByte, OS);
- // Emit the address size opcode prefix as needed.
- if (TSFlags & X86II::AdSize)
- EmitByte(0x67, CurByte, OS);
-
bool Need0FPrefix = false;
switch (TSFlags & X86II::Op0Mask) {
default: assert(0 && "Invalid prefix!");
@@ -806,6 +849,7 @@ EncodeInstruction(const MCInst &MI, raw_ostream &OS,
if ((TSFlags >> 32) & X86II::VEX_4V)
HasVEX_4V = true;
+
// Determine where the memory operand starts, if present.
int MemoryOperand = X86II::getMemoryOperandNo(TSFlags);
if (MemoryOperand != -1) MemoryOperand += CurOp;
@@ -815,7 +859,12 @@ EncodeInstruction(const MCInst &MI, raw_ostream &OS,
else
EmitVEXOpcodePrefix(TSFlags, CurByte, MemoryOperand, MI, Desc, OS);
+
unsigned char BaseOpcode = X86II::getBaseOpcodeFor(TSFlags);
+
+ if ((TSFlags >> 32) & X86II::Has3DNow0F0FOpcode)
+ BaseOpcode = 0x0F; // Weird 3DNow! encoding.
+
unsigned SrcRegNum = 0;
switch (TSFlags & X86II::FormMask) {
case X86II::MRMInitReg:
@@ -828,6 +877,13 @@ EncodeInstruction(const MCInst &MI, raw_ostream &OS,
EmitByte(BaseOpcode, CurByte, OS);
break;
+ case X86II::RawFrmImm8:
+ EmitByte(BaseOpcode, CurByte, OS);
+ EmitImmediate(MI.getOperand(CurOp++),
+ X86II::getSizeOfImm(TSFlags), getImmFixupKind(TSFlags),
+ CurByte, OS, Fixups);
+ EmitImmediate(MI.getOperand(CurOp++), 1, FK_Data_1, CurByte, OS, Fixups);
+ break;
case X86II::RawFrmImm16:
EmitByte(BaseOpcode, CurByte, OS);
EmitImmediate(MI.getOperand(CurOp++),
@@ -963,12 +1019,21 @@ EncodeInstruction(const MCInst &MI, raw_ostream &OS,
RegNum |= GetX86RegNum(MO) << 4;
EmitImmediate(MCOperand::CreateImm(RegNum), 1, FK_Data_1, CurByte, OS,
Fixups);
- } else
+ } else {
+ unsigned FixupKind;
+ if (MI.getOpcode() == X86::MOV64ri32 || MI.getOpcode() == X86::MOV64mi32)
+ FixupKind = X86::reloc_signed_4byte;
+ else
+ FixupKind = getImmFixupKind(TSFlags);
EmitImmediate(MI.getOperand(CurOp++),
- X86II::getSizeOfImm(TSFlags), getImmFixupKind(TSFlags),
+ X86II::getSizeOfImm(TSFlags), MCFixupKind(FixupKind),
CurByte, OS, Fixups);
+ }
}
+ if ((TSFlags >> 32) & X86II::Has3DNow0F0FOpcode)
+ EmitByte(X86II::getBaseOpcodeFor(TSFlags), CurByte, OS);
+
#ifndef NDEBUG
// FIXME: Verify.
generated by cgit v1.1 at 2025-08-25 08:20:52 +0000