make pcrel immediate values relative to the start of the field,

not the end of the field, fixing rdar://7651978

llvm-svn: 96330
This commit is contained in:
Chris Lattner 2010-02-16 05:03:17 +00:00
parent f4ca539af4
commit b29b154904
2 changed files with 18 additions and 8 deletions

View File

@ -153,14 +153,25 @@ EmitImmediate(const MCOperand &DispOp, unsigned Size, MCFixupKind FixupKind,
// If this is a simple integer displacement that doesn't require a relocation,
// emit it now.
if (DispOp.isImm()) {
// FIXME: is this right for pc-rel encoding?? Probably need to emit this as
// a fixup if so.
EmitConstant(DispOp.getImm()+ImmOffset, Size, CurByte, OS);
return;
}
// If we have an immoffset, add it to the expression.
const MCExpr *Expr = DispOp.getExpr();
// 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) ||
FixupKind == MCFixupKind(X86::reloc_riprel_4byte))
ImmOffset -= 4;
if (FixupKind == MCFixupKind(X86::reloc_pcrel_1byte))
ImmOffset -= 1;
if (ImmOffset)
Expr = MCBinaryExpr::CreateAdd(Expr,MCConstantExpr::Create(ImmOffset, Ctx),
Expr = MCBinaryExpr::CreateAdd(Expr, MCConstantExpr::Create(ImmOffset, Ctx),
Ctx);
// Emit a symbolic constant as a fixup and 4 zeros.
@ -192,6 +203,7 @@ void X86MCCodeEmitter::EmitMemModRMByte(const MCInst &MI, unsigned Op,
// the size of the immediate field. If we have this case, add it into the
// expression to emit.
int ImmSize = X86II::hasImm(TSFlags) ? X86II::getSizeOfImm(TSFlags) : 0;
EmitImmediate(Disp, 4, MCFixupKind(X86::reloc_riprel_4byte),
CurByte, OS, Fixups, -ImmSize);
return;
@ -616,8 +628,6 @@ EncodeInstruction(const MCInst &MI, raw_ostream &OS,
// If there is a remaining operand, it must be a trailing immediate. Emit it
// according to the right size for the instruction.
// FIXME: This should pass in whether the value is pc relative or not. This
// information should be aquired from TSFlags as well.
if (CurOp != NumOps)
EmitImmediate(MI.getOperand(CurOp++),
X86II::getSizeOfImm(TSFlags), getImmFixupKind(TSFlags),

View File

@ -3,24 +3,24 @@
movl foo(%rip), %eax
// CHECK: movl foo(%rip), %eax
// CHECK: encoding: [0x8b,0x05,A,A,A,A]
// CHECK: fixup A - offset: 2, value: foo, kind: reloc_riprel_4byte
// CHECK: fixup A - offset: 2, value: foo-4, kind: reloc_riprel_4byte
movb $12, foo(%rip)
// CHECK: movb $12, foo(%rip)
// CHECK: encoding: [0xc6,0x05,A,A,A,A,0x0c]
// CHECK: fixup A - offset: 2, value: foo-1, kind: reloc_riprel_4byte
// CHECK: fixup A - offset: 2, value: foo-5, kind: reloc_riprel_4byte
movw $12, foo(%rip)
// CHECK: movw $12, foo(%rip)
// CHECK: encoding: [0x66,0xc7,0x05,A,A,A,A,0x0c,0x00]
// CHECK: fixup A - offset: 3, value: foo-2, kind: reloc_riprel_4byte
// CHECK: fixup A - offset: 3, value: foo-6, kind: reloc_riprel_4byte
movl $12, foo(%rip)
// CHECK: movl $12, foo(%rip)
// CHECK: encoding: [0xc7,0x05,A,A,A,A,0x0c,0x00,0x00,0x00]
// CHECK: fixup A - offset: 2, value: foo-4, kind: reloc_riprel_4byte
// CHECK: fixup A - offset: 2, value: foo-8, kind: reloc_riprel_4byte
movq $12, foo(%rip)
// CHECK: movq $12, foo(%rip)
// CHECK: encoding: [0x48,0xc7,0x05,A,A,A,A,0x0c,0x00,0x00,0x00]
// CHECK: fixup A - offset: 3, value: foo-4, kind: reloc_riprel_4byte
// CHECK: fixup A - offset: 3, value: foo-8, kind: reloc_riprel_4byte