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PATCH: PR gas/11509: Strange evaluation of symbol containing register
- From: "H.J. Lu" <hongjiu dot lu at intel dot com>
- To: binutils at sourceware dot org
- Cc: jbeulich at novell dot com
- Date: Wed, 21 Apr 2010 11:24:21 -0700
- Subject: PATCH: PR gas/11509: Strange evaluation of symbol containing register
- Reply-to: "H.J. Lu" <hjl dot tools at gmail dot com>
Hi,
I checked in this patch to handle ".equ symbol, reg + NUM" in x86 Intel
syntax. The problem is "reg + NUM" is evaluated and fully resolved at
the first use. This patch stores the register information in X_md
and handles it in i386_intel_simplify_register. However, my patch
doesn't fix
[hjl@gnu-6 pr11509]$ cat 1.s
.intel_syntax noprefix
.eqv param, ebp-4
[hjl@gnu-6 pr11509]$ ./as --32 -o 1.o 1.s
1.s: Assembler messages:
1.s:3: Error: can't make global register symbol `param'
[hjl@gnu-6 pr11509]$
I have no plan to fix it.
Thanks.
H.J.
---
Index: ChangeLog
===================================================================
RCS file: /cvs/src/src/gas/ChangeLog,v
retrieving revision 1.4136
diff -u -p -r1.4136 ChangeLog
--- ChangeLog 21 Apr 2010 17:10:42 -0000 1.4136
+++ ChangeLog 21 Apr 2010 18:08:18 -0000
@@ -1,5 +1,19 @@
2010-04-21 H.J. Lu <hongjiu.lu@intel.com>
+ PR gas/11509
+ * config/tc-i386-intel.c (i386_intel_simplify_register): New.
+ (i386_intel_simplify): Use i386_is_register and
+ i386_intel_simplify_register. Set X_md for O_register and
+ check X_md for O_constant.
+ (i386_intel_operand): Use i386_is_register.
+
+ * config/tc-i386.c (i386_is_register): New.
+ (x86_cons): Initialize the X_md field. Use i386_is_register.
+ (parse_register): Use i386_is_register.
+ (tc_x86_parse_to_dw2regnum): Likewise.
+
+2010-04-21 H.J. Lu <hongjiu.lu@intel.com>
+
* expr.c (expr): Initialize the X_md field.
2010-04-20 Joseph Myers <joseph@codesourcery.com>
Index: config/tc-i386-intel.c
===================================================================
RCS file: /cvs/src/src/gas/config/tc-i386-intel.c,v
retrieving revision 1.9
diff -u -p -r1.9 tc-i386-intel.c
--- config/tc-i386-intel.c 11 Dec 2009 13:42:10 -0000 1.9
+++ config/tc-i386-intel.c 21 Apr 2010 18:08:19 -0000
@@ -233,6 +233,49 @@ static INLINE void i386_intel_fold (expr
}
}
+static int
+i386_intel_simplify_register (expressionS *e)
+{
+ int reg_num;
+
+ if (this_operand < 0 || intel_state.in_offset)
+ {
+ as_bad (_("invalid use of register"));
+ return 0;
+ }
+
+ if (e->X_op == O_register)
+ reg_num = e->X_add_number;
+ else
+ reg_num = e->X_md - 1;
+
+ if (!intel_state.in_bracket)
+ {
+ if (i.op[this_operand].regs)
+ {
+ as_bad (_("invalid use of register"));
+ return 0;
+ }
+ if (i386_regtab[reg_num].reg_type.bitfield.sreg3
+ && i386_regtab[reg_num].reg_num == RegFlat)
+ {
+ as_bad (_("invalid use of pseudo-register"));
+ return 0;
+ }
+ i.op[this_operand].regs = i386_regtab + reg_num;
+ }
+ else if (!intel_state.base && !intel_state.in_scale)
+ intel_state.base = i386_regtab + reg_num;
+ else if (!intel_state.index)
+ intel_state.index = i386_regtab + reg_num;
+ else
+ {
+ /* esp is invalid as index */
+ intel_state.index = i386_regtab + REGNAM_EAX + 4;
+ }
+ return 2;
+}
+
static int i386_intel_simplify (expressionS *);
static INLINE int i386_intel_simplify_symbol(symbolS *sym)
@@ -304,7 +347,8 @@ static int i386_intel_simplify (expressi
intel_state.op_modifier = e->X_op;
/* FALLTHROUGH */
case O_short:
- if (symbol_get_value_expression (e->X_add_symbol)->X_op == O_register)
+ if (i386_is_register (symbol_get_value_expression (e->X_add_symbol),
+ 1))
{
as_bad (_("invalid use of register"));
return 0;
@@ -315,7 +359,8 @@ static int i386_intel_simplify (expressi
break;
case O_full_ptr:
- if (symbol_get_value_expression (e->X_op_symbol)->X_op == O_register)
+ if (i386_is_register (symbol_get_value_expression (e->X_op_symbol),
+ 1))
{
as_bad (_("invalid use of register"));
return 0;
@@ -328,40 +373,6 @@ static int i386_intel_simplify (expressi
i386_intel_fold (e, e->X_op_symbol);
break;
- case O_register:
- if (this_operand < 0 || intel_state.in_offset)
- {
- as_bad (_("invalid use of register"));
- return 0;
- }
- if (!intel_state.in_bracket)
- {
- if (i.op[this_operand].regs)
- {
- as_bad (_("invalid use of register"));
- return 0;
- }
- if (i386_regtab[e->X_add_number].reg_type.bitfield.sreg3
- && i386_regtab[e->X_add_number].reg_num == RegFlat)
- {
- as_bad (_("invalid use of pseudo-register"));
- return 0;
- }
- i.op[this_operand].regs = i386_regtab + e->X_add_number;
- }
- else if (!intel_state.base && !intel_state.in_scale)
- intel_state.base = i386_regtab + e->X_add_number;
- else if (!intel_state.index)
- intel_state.index = i386_regtab + e->X_add_number;
- else
- {
- /* esp is invalid as index */
- intel_state.index = i386_regtab + REGNAM_EAX + 4;
- }
- e->X_op = O_constant;
- e->X_add_number = 0;
- return 2;
-
case O_multiply:
if (this_operand >= 0 && intel_state.in_bracket)
{
@@ -418,6 +429,22 @@ static int i386_intel_simplify (expressi
break;
}
+
+ case O_register:
+ ret = i386_intel_simplify_register (e);
+ if (ret == 2)
+ {
+ gas_assert (e->X_add_number < (unsigned short) -1);
+ e->X_md = (unsigned short) e->X_add_number + 1;
+ e->X_op = O_constant;
+ e->X_add_number = 0;
+ }
+ return ret;
+
+ case O_constant:
+ if (e->X_md)
+ return i386_intel_simplify_register (e);
+
/* FALLTHROUGH */
default:
if (e->X_add_symbol && !i386_intel_simplify_symbol (e->X_add_symbol))
@@ -832,7 +859,7 @@ i386_intel_operand (char *operand_string
break;
intel_state.seg = expP->X_add_symbol;
}
- if (expP->X_op != O_register)
+ if (!i386_is_register (expP, 1))
{
as_bad (_("segment register name expected"));
return 0;
Index: config/tc-i386.c
===================================================================
RCS file: /cvs/src/src/gas/config/tc-i386.c,v
retrieving revision 1.431
diff -u -p -r1.431 tc-i386.c
--- config/tc-i386.c 22 Mar 2010 13:49:50 -0000 1.431
+++ config/tc-i386.c 21 Apr 2010 18:08:19 -0000
@@ -3534,6 +3534,15 @@ swap_operands (void)
}
}
+static int
+i386_is_register (const expressionS *e, int is_intel_syntax)
+{
+ return (e->X_op == O_register
+ || (is_intel_syntax
+ && e->X_op == O_constant
+ && e->X_md));
+}
+
/* Try to ensure constant immediates are represented in the smallest
opcode possible. */
static void
@@ -6451,6 +6460,7 @@ x86_cons (expressionS *exp, int size)
{
intel_syntax = -intel_syntax;
+ exp->X_md = 0;
if (size == 4 || (object_64bit && size == 8))
{
/* Handle @GOTOFF and the like in an expression. */
@@ -6477,7 +6487,7 @@ x86_cons (expressionS *exp, int size)
if (exp->X_op == O_constant
|| exp->X_op == O_absent
|| exp->X_op == O_illegal
- || exp->X_op == O_register
+ || i386_is_register (exp, intel_syntax)
|| exp->X_op == O_big)
{
char c = *input_line_pointer;
@@ -7956,7 +7966,7 @@ parse_register (char *reg_string, char *
{
const expressionS *e = symbol_get_value_expression (symbolP);
- know (e->X_op == O_register);
+ know (i386_is_register (e, intel_syntax));
know (e->X_add_number >= 0
&& (valueT) e->X_add_number < i386_regtab_size);
r = i386_regtab + e->X_add_number;
@@ -8863,7 +8873,7 @@ tc_x86_parse_to_dw2regnum (expressionS *
register_chars['.'] = saved_register_dot;
allow_naked_reg = saved_naked_reg;
- if (exp->X_op == O_register && exp->X_add_number >= 0)
+ if (i386_is_register (exp, intel_syntax) && exp->X_add_number >= 0)
{
if ((addressT) exp->X_add_number < i386_regtab_size)
{
Index: testsuite/ChangeLog
===================================================================
RCS file: /cvs/src/src/gas/testsuite/ChangeLog,v
retrieving revision 1.1657
diff -u -p -r1.1657 ChangeLog
--- testsuite/ChangeLog 20 Apr 2010 15:54:48 -0000 1.1657
+++ testsuite/ChangeLog 21 Apr 2010 18:08:19 -0000
@@ -1,3 +1,9 @@
+2010-04-21 H.J. Lu <hongjiu.lu@intel.com>
+
+ PR gas/11509
+ * gas/i386/equ.s: Add tests for ".equ symbol, reg + NUM".
+ * gas/i386/equ.d: Updated.
+
2010-04-20 Nick Clifton <nickc@redhat.com>
PR gas/11507
Index: testsuite/gas/i386/equ.d
===================================================================
RCS file: /cvs/src/src/gas/testsuite/gas/i386/equ.d,v
retrieving revision 1.3
diff -u -p -r1.3 equ.d
--- testsuite/gas/i386/equ.d 20 Apr 2009 06:31:50 -0000 1.3
+++ testsuite/gas/i386/equ.d 21 Apr 2010 18:08:19 -0000
@@ -22,4 +22,6 @@ Disassembly of section .text:
[ 0-9a-f]+:[ 0-9a-f]+mov[ ]+%gs:\(%edx,%edx,8\),%edx
[ 0-9a-f]+:[ 0-9a-f]+fadd[ ]+%st\(1\),%st
[ 0-9a-f]+:[ 0-9a-f]+fadd[ ]+%st\(7\),%st
+[ 0-9a-f]+:[ 0-9a-f]+mov[ ]+0x4\(%edx\),%eax
+[ 0-9a-f]+:[ 0-9a-f]+mov[ ]+0x4\(%edx\),%eax
#pass
Index: testsuite/gas/i386/equ.s
===================================================================
RCS file: /cvs/src/src/gas/testsuite/gas/i386/equ.s,v
retrieving revision 1.4
diff -u -p -r1.4 equ.s
--- testsuite/gas/i386/equ.s 20 Apr 2009 06:31:50 -0000 1.4
+++ testsuite/gas/i386/equ.s 21 Apr 2010 18:08:19 -0000
@@ -39,6 +39,9 @@ _start:
fadd x
.equ x, st(7)
fadd x
+ .equ r, edx + 4
+ mov eax, [r]
+ mov eax, [r]
.if s <> gs
.err