zero.X_op = O_constant;
zero.X_add_number = 0;
zero.X_unsigned = 0;
+ zero.X_extrabit = 0;
clean_up_expression (&zero);
expressionP = &zero;
}
e.X_op = O_constant;
e.X_add_number = value;
e.X_unsigned = 1;
+ e.X_extrabit = 0;
return make_expr_symbol (&e);
}
something like ``.quad 0x80000000'' is not sign extended even
though it appears negative if valueT is 32 bits. */
expressionP->X_unsigned = 1;
+ expressionP->X_extrabit = 0;
/* Digits, assume it is a bignum. */
This is compatible with other people's
assemblers. Sigh. */
expressionP->X_unsigned = 0;
+ if (expressionP->X_add_number)
+ expressionP->X_extrabit ^= 1;
}
else if (c == '~' || c == '"')
expressionP->X_add_number = ~ expressionP->X_add_number;
expressionP->X_add_number = i >= expressionP->X_add_number;
expressionP->X_op = O_constant;
expressionP->X_unsigned = 1;
+ expressionP->X_extrabit = 0;
}
}
else if (expressionP->X_op != O_illegal
/* NOTREACHED */
}
+/* Implement "word-size + 1 bit" addition for
+ {resultP->X_extrabit:resultP->X_add_number} + {rhs_highbit:amount}. This
+ is used so that the full range of unsigned word values and the full range of
+ signed word values can be represented in an O_constant expression, which is
+ useful e.g. for .sleb128 directives. */
+
+static void
+add_to_result (expressionS *resultP, offsetT amount, int rhs_highbit)
+{
+ valueT ures = resultP->X_add_number;
+ valueT uamount = amount;
+
+ resultP->X_add_number += amount;
+
+ resultP->X_extrabit ^= rhs_highbit;
+
+ if (ures + uamount < ures)
+ resultP->X_extrabit ^= 1;
+}
+
+/* Similarly, for subtraction. */
+
+static void
+subtract_from_result (expressionS *resultP, offsetT amount, int rhs_highbit)
+{
+ valueT ures = resultP->X_add_number;
+ valueT uamount = amount;
+
+ resultP->X_add_number -= amount;
+
+ resultP->X_extrabit ^= rhs_highbit;
+
+ if (ures < uamount)
+ resultP->X_extrabit ^= 1;
+}
+
/* Parse an expression. */
segT
&& (md_register_arithmetic || resultP->X_op != O_register))
{
/* X + constant. */
- resultP->X_add_number += right.X_add_number;
+ add_to_result (resultP, right.X_add_number, right.X_extrabit);
}
/* This case comes up in PIC code. */
else if (op_left == O_subtract
symbol_get_frag (right.X_add_symbol),
&frag_off))
{
- resultP->X_add_number -= right.X_add_number;
- resultP->X_add_number -= frag_off / OCTETS_PER_BYTE;
- resultP->X_add_number += (S_GET_VALUE (resultP->X_add_symbol)
- - S_GET_VALUE (right.X_add_symbol));
+ offsetT symval_diff = S_GET_VALUE (resultP->X_add_symbol)
+ - S_GET_VALUE (right.X_add_symbol);
+ subtract_from_result (resultP, right.X_add_number, right.X_extrabit);
+ subtract_from_result (resultP, frag_off / OCTETS_PER_BYTE, 0);
+ add_to_result (resultP, symval_diff, symval_diff < 0);
resultP->X_op = O_constant;
resultP->X_add_symbol = 0;
}
&& (md_register_arithmetic || resultP->X_op != O_register))
{
/* X - constant. */
- resultP->X_add_number -= right.X_add_number;
+ subtract_from_result (resultP, right.X_add_number, right.X_extrabit);
}
else if (op_left == O_add && resultP->X_op == O_constant
&& (md_register_arithmetic || right.X_op != O_register))
resultP->X_op = right.X_op;
resultP->X_add_symbol = right.X_add_symbol;
resultP->X_op_symbol = right.X_op_symbol;
- resultP->X_add_number += right.X_add_number;
+ add_to_result (resultP, right.X_add_number, right.X_extrabit);
retval = rightseg;
}
else if (resultP->X_op == O_constant && right.X_op == O_constant)
/* Constant + constant (O_add) is handled by the
previous if statement for constant + X, so is omitted
here. */
- case O_subtract: resultP->X_add_number -= v; break;
+ case O_subtract:
+ subtract_from_result (resultP, v, 0);
+ break;
case O_eq:
resultP->X_add_number =
resultP->X_add_number == v ? ~ (offsetT) 0 : 0;
resultP->X_op = op_left;
resultP->X_op_symbol = right.X_add_symbol;
if (op_left == O_add)
- resultP->X_add_number += right.X_add_number;
+ add_to_result (resultP, right.X_add_number, right.X_extrabit);
else if (op_left == O_subtract)
{
- resultP->X_add_number -= right.X_add_number;
+ subtract_from_result (resultP, right.X_add_number,
+ right.X_extrabit);
if (retval == rightseg
&& SEG_NORMAL (retval)
&& !S_FORCE_RELOC (resultP->X_add_symbol, 0)
resultP->X_op = op_left;
resultP->X_add_number = 0;
resultP->X_unsigned = 1;
+ resultP->X_extrabit = 0;
}
if (retval != rightseg)
}
/* Convert O_constant expression EXP into the equivalent O_big representation.
- Take the sign of the number from X_unsigned rather than X_add_number. */
+ Take the sign of the number from SIGN rather than X_add_number. */
static void
-convert_to_bignum (expressionS *exp)
+convert_to_bignum (expressionS *exp, int sign)
{
valueT value;
unsigned int i;
}
/* Add a sequence of sign bits if the top bit of X_add_number is not
the sign of the original value. */
- if ((exp->X_add_number < 0) != !exp->X_unsigned)
- generic_bignum[i++] = exp->X_unsigned ? 0 : LITTLENUM_MASK;
+ if ((exp->X_add_number < 0) == !sign)
+ generic_bignum[i++] = sign ? LITTLENUM_MASK : 0;
exp->X_op = O_big;
exp->X_add_number = i;
}
if (op == O_constant && nbytes > sizeof (valueT))
{
extra_digit = exp->X_unsigned ? 0 : -1;
- convert_to_bignum (exp);
+ convert_to_bignum (exp, !exp->X_unsigned);
op = O_big;
}
exp->X_add_number = value;
exp->X_op = O_constant;
exp->X_unsigned = 1;
+ exp->X_extrabit = 0;
}
}
}
else if (op == O_constant
&& sign
- && (exp->X_add_number < 0) != !exp->X_unsigned)
+ && (exp->X_add_number < 0) == !exp->X_extrabit)
{
/* We're outputting a signed leb128 and the sign of X_add_number
doesn't reflect the sign of the original value. Convert EXP
to a correctly-extended bignum instead. */
- convert_to_bignum (exp);
+ convert_to_bignum (exp, exp->X_extrabit);
op = O_big;
}
projects / binutils-gdb.git / commitdiff