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gas: invoke md_optimize_expr() also for unary expressions

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Give backends a chance to see these, just as they can see binary ones.
Most of those which use this hook already cope with NULL being passed
for the left operand (typically because of checking the operator first).
Adjust the two which don't.

Take the opportunity and also document the hook.
This commit is contained in:
Jan Beulich 2023-05-19 09:16:29 +02:00
parent 762acf217c
commit 6f5ee7a3e9
4 changed files with 40 additions and 22 deletions
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1
gas/config/tc-hppa.c
View File

@ -6354,6 +6354,7 @@ hppa_force_reg_syms_absolute (expressionS *resultP,
expressionS *rightP)
{
if (fudge_reg_expressions
&& resultP
&& rightP->X_op == O_register
&& resultP->X_op == O_register)
{

6
gas/config/tc-ppc.c
View File

@ -945,9 +945,9 @@ ppc_optimize_expr (expressionS *left, operatorT op, expressionS *right)
}
/* Accept the above plus <cr bit>, and <cr bit> plus the above. */
if (right->X_op == O_register
if (op == O_add
&& left->X_op == O_register
&& op == O_add
&& right->X_op == O_register
&& ((right->X_md == PPC_OPERAND_CR_BIT
&& left->X_md == (PPC_OPERAND_CR_REG | PPC_OPERAND_CR_BIT))
|| (right->X_md == (PPC_OPERAND_CR_REG | PPC_OPERAND_CR_BIT)
@ -959,7 +959,7 @@ ppc_optimize_expr (expressionS *left, operatorT op, expressionS *right)
}
/* Accept reg +/- constant. */
if (left->X_op == O_register
if (left && left->X_op == O_register
&& !((op == O_add || op == O_subtract) && right->X_op == O_constant))
as_warn (_("invalid register expression"));

8
gas/doc/internals.texi
View File

@ -1047,6 +1047,14 @@ pointer, for any expression that can not be recognized. When the function
is called, @code{input_line_pointer} will point to the start of the
expression.
@item md_optimize_expr
@cindex md_optimize_expr
GAS will call this function before trying to carry out certain operations,
like the adding of two constants. The function is passed the left-hand
operand, an @code{expressionS} pointer, the operator, an @code{operatorT}
value, and the right-hand operand, again an @code{expressionS} pointer. For
unary expressions NULL is passed as first argument.
@item md_register_arithmetic
@cindex md_register_arithmetic
If this macro is defined and evaluates to zero then GAS will not fold

47
gas/expr.c
View File

@ -764,6 +764,7 @@ operand (expressionS *expressionP, enum expr_mode mode)
symbolS *symbolP; /* Points to symbol. */
char *name; /* Points to name of symbol. */
segT segment;
operatorT op = O_absent; /* For unary operators. */
/* All integers are regarded as unsigned unless they are negated.
This is because the only thing which cares whether a number is
@ -1029,19 +1030,33 @@ operand (expressionS *expressionP, enum expr_mode mode)
/* '~' is permitted to start a label on the Delta. */
if (is_name_beginner (c))
goto isname;
/* Fall through. */
op = O_bit_not;
goto unary;
case '!':
op = O_logical_not;
goto unary;
case '-':
op = O_uminus;
/* Fall through. */
case '+':
{
#ifdef md_operator
unary:
#endif
operand (expressionP, mode);
#ifdef md_optimize_expr
if (md_optimize_expr (NULL, op, expressionP))
{
/* Skip. */
;
}
else
#endif
if (expressionP->X_op == O_constant)
{
/* input_line_pointer -> char after operand. */
if (c == '-')
if (op == O_uminus)
{
expressionP->X_add_number
= - (addressT) expressionP->X_add_number;
@ -1052,13 +1067,13 @@ operand (expressionS *expressionP, enum expr_mode mode)
if (expressionP->X_add_number)
expressionP->X_extrabit ^= 1;
}
else if (c == '~' || c == '"')
else if (op == O_bit_not)
{
expressionP->X_add_number = ~ expressionP->X_add_number;
expressionP->X_extrabit ^= 1;
expressionP->X_unsigned = 0;
}
else if (c == '!')
else if (op == O_logical_not)
{
expressionP->X_add_number = ! expressionP->X_add_number;
expressionP->X_unsigned = 1;
@ -1067,7 +1082,7 @@ operand (expressionS *expressionP, enum expr_mode mode)
}
else if (expressionP->X_op == O_big
&& expressionP->X_add_number <= 0
&& c == '-'
&& op == O_uminus
&& (generic_floating_point_number.sign == '+'
|| generic_floating_point_number.sign == 'P'))
{
@ -1082,7 +1097,7 @@ operand (expressionS *expressionP, enum expr_mode mode)
{
int i;
if (c == '~' || c == '-')
if (op == O_uminus || op == O_bit_not)
{
for (i = 0; i < expressionP->X_add_number; ++i)
generic_bignum[i] = ~generic_bignum[i];
@ -1095,7 +1110,7 @@ operand (expressionS *expressionP, enum expr_mode mode)
generic_bignum[i] = ~(LITTLENUM_TYPE) 0;
}
if (c == '-')
if (op == O_uminus)
for (i = 0; i < expressionP->X_add_number; ++i)
{
generic_bignum[i] += 1;
@ -1103,7 +1118,7 @@ operand (expressionS *expressionP, enum expr_mode mode)
break;
}
}
else if (c == '!')
else if (op == O_logical_not)
{
for (i = 0; i < expressionP->X_add_number; ++i)
if (generic_bignum[i] != 0)
@ -1117,15 +1132,10 @@ operand (expressionS *expressionP, enum expr_mode mode)
else if (expressionP->X_op != O_illegal
&& expressionP->X_op != O_absent)
{
if (c != '+')
if (op != O_absent)
{
expressionP->X_add_symbol = make_expr_symbol (expressionP);
if (c == '-')
expressionP->X_op = O_uminus;
else if (c == '~' || c == '"')
expressionP->X_op = O_bit_not;
else
expressionP->X_op = O_logical_not;
expressionP->X_op = op;
expressionP->X_add_number = 0;
}
else if (!md_register_arithmetic && expressionP->X_op == O_register)
@ -1288,8 +1298,7 @@ operand (expressionS *expressionP, enum expr_mode mode)
#ifdef md_operator
{
operatorT op = md_operator (name, 1, &c);
op = md_operator (name, 1, &c);
switch (op)
{
case O_uminus: