* [binutils-gdb] gas: invoke md_optimize_expr() also for unary expressions
@ 2023-05-19 7:19 Jan Beulich
0 siblings, 0 replies; only message in thread
From: Jan Beulich @ 2023-05-19 7:19 UTC (permalink / raw)
To: bfd-cvs
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=6f5ee7a3e9239cf82142d7abd4b2ad687076cfc1
commit 6f5ee7a3e9239cf82142d7abd4b2ad687076cfc1
Author: Jan Beulich <jbeulich@suse.com>
Date: Fri May 19 09:16:29 2023 +0200
gas: invoke md_optimize_expr() also for unary expressions
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.
Diff:
---
gas/config/tc-hppa.c | 1 +
gas/config/tc-ppc.c | 6 +++---
gas/doc/internals.texi | 8 ++++++++
gas/expr.c | 47 ++++++++++++++++++++++++++++-------------------
4 files changed, 40 insertions(+), 22 deletions(-)
diff --git a/gas/config/tc-hppa.c b/gas/config/tc-hppa.c
index c91b2b557a0..2e5de070b94 100644
--- a/gas/config/tc-hppa.c
+++ b/gas/config/tc-hppa.c
@@ -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)
{
diff --git a/gas/config/tc-ppc.c b/gas/config/tc-ppc.c
index 8b1d995da6d..a8b034c88ab 100644
--- a/gas/config/tc-ppc.c
+++ b/gas/config/tc-ppc.c
@@ -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"));
diff --git a/gas/doc/internals.texi b/gas/doc/internals.texi
index 56f10fd16fa..3eea25b758c 100644
--- a/gas/doc/internals.texi
+++ b/gas/doc/internals.texi
@@ -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
diff --git a/gas/expr.c b/gas/expr.c
index b83296cc10d..204cfebc4c7 100644
--- a/gas/expr.c
+++ b/gas/expr.c
@@ -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:
^ permalink raw reply [flat|nested] only message in thread
only message in thread, other threads:[~2023-05-19 7:19 UTC | newest]
Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-05-19 7:19 [binutils-gdb] gas: invoke md_optimize_expr() also for unary expressions Jan Beulich
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).