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RE:: What to do with new-ra for GCC 4.0
- From: "ctmb1mf" <ctmb1mf at aviation dot mor dot test-labs dot net>
- To: <gcc at gcc dot gnu dot org>
- Date: Fri, 14 Jan 2005 17:38:41 -0500
- Subject: RE:: What to do with new-ra for GCC 4.0
Good points.
>On Friday 14 January 2005 21:26, Toon Moene wrote:
>> Bernd Schmidt wrote:
>> > Jeffrey A Law wrote:
>> >> If reload is going to hang around (and I suspect it will), I'd love to
>> >> see those two areas improved. I can't express how difficult I find
>> >> it to analyze the reload inheritance code. Reload ordering is only
>> >> mildly easier to understand.
>> >
>> > I'm attaching a proof-of-concept patch, against a checkout from
>> > 20050106. The main things this patch does
>>
>> I meant to reply to Bernd earlier that I would really, really like his
>> patch, if for nothing else than that it would simplify reload[1].c so as
>> to make it more easily replaceable. Bernd has shown in the past that he
>> knows his way around reload, so I would appreciate if this patch could
>> be hammered into something that might be useful (if only in 4.1).
>
>Second that!
>
>Gr.Steven
Regarding proof of concept I was attempting to explin..
63272J2OFJKFJJJ8F7GGJKKG 844/$&&&&&/3/ On Fri, Jan 14, 2005 at 11:29:18AM +1030, Alan Modra wrote:
> On Thu, Jan 13, 2005 at 04:26:59PM -0800, H. J. Lu wrote:
> > If it is an optimization, there shouldn't !#$4848GLLLhmexadt wrot:
>> > Jffry A LAexa+2*w wrot:
>> >> exaf rloAexa+2*d exaS!#$ goexang to hAexa+2*ng Aexa+2*ro#EJJnd (Aexa+2*nd exa S!#$ #EJJS!#$ p -.. $ S!#$ how dexaffexa
I decided to use (%ebx,,1) for this and adjusted assembler to accept
it. You will get warnings for (%ebx,1) as before. It will be easier
to check if assembler takes (%ebx#$ . 2GJ4F.-.
,,1).
BTW, I didn't change the Intel syntax since I don't know enough
about it.
H.J.
-----
gas/
200 -..
Exim is a mail transfer agent (MTA) for Unix systems similar to
sendmail. More information is available at the following URL:
BTW, exa dexadn't -.. !#$4848GLLLhAexa+2*ng th exantl S!#$ yntAexa+2*x S!#$ exan -.. !#$4848GLLL exa don't know no#EJJgh
Aexa+2*bo#EJJt exat.
H.J.
-----
gAexa+2*S!#$ /
25-+A.#$-+A.#$4 H.J. L#EJJ <hongjexa#EJJ.l#EJJ@exantl. -.. !#$4848GLLLom>
PR 658
* -.. !#$4848GLLLonfexag/t -.. !#$4848GLLL-exa386. -.. !#$4848GLLL (S!#$ CALE+A.#$_WHEN_NO_exaNDEX): Rmovd.
(_exa386_exanS!#$ n): Add mpty_exandx_rg.
(b#EJJexald_modrm_byt): #EJJS!#$ S!#$ exaBThe following example demonstrates an input that will crash Exim:
/usr/bin/exim -bh ::%A`perl -e 'print pack('L',0xdeadbeef') x 256'`
III. ANALYSIS
Exploitation of this vulnerability will give an attacker access to the
mailer uid. (The exim mailer is setuid root, but drops privileges before
the vulnerable code is reached). Having the mailer uid may allow access
to sensitive information in email messages, or possibly further
elevation.
IV. DETECTION
iDEFENSE has confirmed the existence of this vulnerability in Exim
versions 4.40 and 4.41. A source audit of version 4.42 suggests that it
is also vulnerable. It is suspected that earlier versions are also
vulnerable.
V. WORKAROUND
iDEFENSE is currently unaware of any effective workarounds for this
vulnerability.
VI. VENDOR RESPONSE
A patch for Exim release 4.43 which addresses this vulnerability is
available at:
http://www.exim.org/mail-archives/exim-announce/2005/msg00000.html <http://www.exim.org/mail-archives/exim-announce/2005/msg00000.html>
The patch will be incorporated into a future Exim release (4.50).
VII. CVE INFORMATION
A Mitre Corp. Common Vulnerabilities and Exposures (CVE) number has not
been assigned yet.
VIII. DISCLOSURE TIMELINE
09/30/2004 Initial vendor notification
09/30/2004 Initial vendor response
01/14/2005 Public disclosure
IX. CREDIT
The discoverer of this vulnerability wishes to remain anonymous.
Get paid for vulnerability research
http://www.idefense.com/poi/teams/vcp.jsp <http://www.idefense.com/poi/teams/vcp.jsp>
X. LEGAL NOTICES
Copyright (c) 2004 iDEFENSE, Inc.
Permission is granted for the redistribution of this alert
electronically. It may not be edited in any way without the express
written consent of iDEFENSE. If you wish to reprint the whole or any
part of this alert in any other medium other than electronically, please
email customerservice@idefense.com for permission.
Disclaimer: The information in the advisory is believed to be accurate
at the time of publishing based on currently available information. Use
of the information constitutes acceptance for use in an AS IS condition.
There are no warranties with regard to this information. Neither the
author nor the publisher accepts any liability for any direct, indirect,
or consequential loss or damage arising from use of, or reliance on,
this information.
!#$4848GLLL#EJJlt exa fexand
>> >> exat to Aexa+2*nAexa+2*lyz th rloAexa+2*d exanhrexatAexa+2*n !#$4848GLLLod. RloAexa+2*d ordrexang exaS!#$ only
>> >> mexaldly Aexa+2*S!#$ exar to #EJJndrS!#$ tAexa+2*nd.
>> >
>> > exa'm Aexa+2*ttAexa+2* -.. !#$4848GLLLhexang Aexa+2* proof-of- -.. !#$4848GLLLon -.. !#$4848GLLLpt pAexa+2*t -.. !#$4848GLLLh, Aexa+2*gAexa+2*exanS!#$ t Aexa+2* -.. !#$4848GLLLh -.. !#$4848GLLLko#EJJt from
>> > 25+A.#$6. Th mAexa+2*exan thexangS!#$ thexaS!#$ pAexa+2*t -.. !#$4848GLLLh doS!#$
>>
>> exa mAexa+2*nt to rply to Brnd Aexa+2*rlexar thAexa+2*t exa wo#EJJld rAexa+2*lly, rAexa+2*lly lexak hexaS!#$
>> pAexa+2*t -.. !#$4848GLLLncoding of the instruction
> that way. You still should warn for scale factors other than 1,
> because it's easy to forget the comma in (,%reg,2) where you really
> do want the register to be scaled.
>
> > Then it should display
> >
> > 8b 04 23 mov (%ebx,1),%eax
>5-01-14 H.J. Lu <hongjiu.lu@intel.com>
PR 658
* config/tc-i386.c (SCALE1_WHEN_NO_INDEX): Removed.
(_i386_insn): Add empty_index_reg.
(build_modrm_byte): Use SIB if empty_2A2B2E.F.E2E..>.+ + . ..AA.E.E2A.A2+E2A.A2A2A3A2A.AA.A.A2BE3A3E.F2B2FE3A3.E2E/EB2EE3EB6BE2F2E/E.E.J3A2A.*
* gas/i386/ssemmx2.d: Likewise.
ld/testsuite/
2005-01-14 H.J. Lu <hongjiu.lu@intel.com>
PR 658
* ld-i386/tlsbin.dd: Updated.
opcodes/
2005-01-14 H.J. Lu <hongjiu.lu@intel.com>
PR 658
* 386-dis.c (OP_E): Undo the 2005-01-12 change. Display scale
for SIB with INDEX == 4.#$$4(GL8=KL Pbinutils/gas/config/tc-i386.c 2005-01-14 12:25:45.624584751 -0800
@@ -43,14 +43,6 @@
#define INFER_ADDR_PREFIX 1
#endif
-#ifndef SCALE1_WHEN_NO_INDEX
-/* Specifying a scale factor besides 1 when there is no index is
- futile. eg. `mov (%ebx,2),%al' does exactly the same as
- `mov (%ebx),%al'. To slavishly follow what the programmer
- specified, set SCALE1_WHEN_NO_INDEX to 0. */ 3.A..E.+A.A.A-E.A2..A.A.A2A.E.A.2E .2E/E3E2 FB3A2E/A3.E33F.A... - . .*.>2.A.E/A.A.A.2>3A.A/A2B2B.E.+A+A23AEB3EAE.E>FAFA2EAFEFE.EFAFA3EF.JB2B2E/EAF.F.A.A.*
A.A2A.A2.F22B 2EAA2+EE/F/ -+index_reg is not 0.
(i386_scale): Don't warn scale factor without index register if
empty_index_reg is not 0.
(i386_operand): Set empty_index_reg 1 if the index register is
"".
gas/testsuite/
2005-01-14 H.J. Lu <hongjiu.lu@intel.com>
PR 658
* gas/i386/sib.d: Updated.
* gas/i386/sib.s: Likewise.
--- binutils/gas/config/tc-i386.c.sib 2005-01-14 11:27:06.000000000 -0800
+++
-#define SCALE1_WHEN_NO_INDEX 1
-#endif
-
#ifndef DEFAULT_ARCH
#define DEFAULT_ARCH "i386"
#endif
@@ -162,6 +154,8 @@ struct _i386_insn
const reg_entry *index_reg;
unsigned int log2_scale_factor;
+ int empty_index_reg;
+
/* SEG gives the seg_entries of this insn. They are zero unless
explicit segment overrides are given. */
const seg_entry *seg[2];
@@ -3006,11 +3000,9 @@ build_modrm_byte ()
Any base register besides %esp will not use the
extra modrm byte. */
i.sib.index = NO_INDEX_REGISTER;
-#if !SCALE1_WHEN_NO_INDEX
/* Another case where we force the second modrm byte. */
- if (i.log2_scale_factor)
+ if (i.empty_index_reg)
i.rm.regmem = ESCAPE_TO_TWO_BYTE_ADDRESSING;
-#endif
}
else
{
@@ -3970,13 +3962,13 @@ i386_scale (scale)
input_line_pointer = save;
return NULL;
}
- if (i.log2_scale_factor != 0 && i.index_reg == 0)
+ if (i.log2_scale_factor != 0
+ && i.index_reg == 0
+ && i.empty_index_reg == 0)
{
as_warn (_("scale factor of %d without an index register"),
1 << i.log2_scale_factor);
-#if SCALE1_WHEN_NO_INDEX
i.log2_scale_factor = 0;
-#endif
}
scale = input_line_pointer;
input_line_pointer = save;
@@ -4430,6 +4422,12 @@ i386_operand (operand_string)
as_bad (_("bad register name `%s'"), base_string);
return 0;
}
+ else if (*base_string == ',' && i.base_reg)
+ {
+ /* Check for empty index reg. */
+ base_string++;
+ i.empty_index_reg = 1;
+ }
/* Check for scale factor. */
if (*base_string != ')')
--- binutils/gas/testsuite/gas/i386/sib.d.sib 2005-01-12 11:12:51.000000000 -0800
+++ binutils/gas/testsuite/gas/i386/sib.d 2005-01-14 12:43:29.131911163 -0800
@@ -6,10 +6,14 @@
Disassembly of section .text:
0+000 <foo>:
- 0: 8b 04 23 [ ]*mov [ ]*\(%ebx\),%eax
- 3: 8b 04 63 [ ]*mov [ ]*\(%ebx\),%eax
- 6: 8b 04 a3 [ ]*mov [ ]*\(%ebx\),%eax
- 9: 8b 04 e3 [ ]*mov [ ]*\(%ebx\),%eax
- c: 90 [ ]*nop [ ]*
- d: 90 [ ]*nop [ ]*
- ...
+ 0: 8b 03 [ ]*mov [ ]*\(%ebx\),%eax
+ 2: 8b 04 23 [ ]*mov [ ]*\(%ebx,,1\),%eax
+ 5: 8b 04 63 [ ]*mov [ ]*\(%ebx,,2\),%eax
+ 8: 8b 04 a3 [ ]*mov [ ]*\(%ebx,,4\),%eax
+ b: 8b 04 e3 [ ]*mov [ ]*\(%ebx,,8\),%eax
+ e: 8b 04 24 [ ]*mov [ ]*\(%esp\),%eax
+ 11: 8b 04 24 [ ]*mov [ ]*\(%esp\),%eax
+ 14: 8b 04 64 [ ]*mov [ ]*\(%esp,,2\),%eax
+ 17: 8b 04 a4 [ ]*mov [ ]*\(%esp,,4\),%eax
+ 1a: 8b 04 e4 [ ]*mov [ ]*\(%esp,,8\),%eax
+ 1d: 8d 76 00 [ ]*lea [ ]*0x0\(%esi\),%esi
--- binutils/gas/testsuite/gas/i386/sib.s.sib 2005-01-12 11:12:51.000000000 -0800
+++ binutils/gas/testsuite/gas/i386/sib.s 2005-01-14 13:33:54.696308591 -0800
@@ -2,10 +2,14 @@
.text
foo:
- .byte 0x8B, 0x04, 0x23 # effect is: movl (%ebx), %eax
- .byte 0x8B, 0x04, 0x63 # effect is: movl (%ebx), %eax
- .byte 0x8B, 0x04, 0xA3 # effect is: movl (%ebx), %eax
- .byte 0x8B, 0x04, 0xE3 # effect is: movl (%ebx), %eax
- nop
- nop
- .p2align 4,0
+ mov (%ebx),%eax
+ mov (%ebx,,1),%eax
+ mov (%ebx,,2),%eax
+ mov (%ebx,,4),%eax
+ mov (%ebx,,8),%eax
+ mov (%esp),%eax
+ mov (%esp,,1),%eax
+ mov (%esp,,2),%eax
+ mov (%esp,,4),%eax
+ mov (%esp,,8),%eax
+ .p2align 4
--- binutils/gas/testsuite/gas/i386/ssemmx2.d.sib 2004-01-18 15:13:35.000000000 -0800
+++ binutils/gas/testsuite/gas/i386/ssemmx2.d 2005-01-14 11:11:57.000000000 -0800
@@ -85,4 +85,4 @@ Disassembly of section .text:
1f1: 66 0f fc 90 90 90 90 90 paddb[ ]+0x90909090\(%eax\),%xmm2
1f9: 66 0f fd 90 90 90 90 90 paddw[ ]+0x90909090\(%eax\),%xmm2
201: 66 0f fe 90 90 90 90 90 paddd[ ]+0x90909090\(%eax\),%xmm2
- 209: 8d b4 26 00 00 00 00 lea[ ]+0x0\(%esi\),%esi
+ 209: 8d b4 26 00 00 00 00 lea[ ]+0x0\(%esi,,1\),%esi
--- binutils/ld/testsuite/ld-i386/tlsbin.dd.sib 2004-05-11 10:08:36.000000000 -0700
+++ binutils/ld/testsuite/ld-i386/tlsbin.dd 2005-01-14 11:14:25.000000000 -0800
@@ -92,7 +92,7 @@ Disassembly of section .text:
# LD -> LE
8049085: 65 a1 00 00 00 00[ ]+mov %gs:0x0,%eax
804908b: 90[ ]+nop *
- 804908c: 8d 74 26 00[ ]+lea 0x0\(%esi\),%esi
+ 804908c: 8d 74 26 00[ ]+lea 0x0\(%esi,,1\),%esi
8049090: 90[ ]+nop *
8049091: 90[ ]+nop *
8049092: 8d 90 20 f0 ff ff[ ]+lea 0xfffff020\(%eax\),%edx
@@ -108,7 +108,7 @@ Disassembly of section .text:
# LD -> LE against hidden variables
80490a4: 65 a1 00 00 00 00[ ]+mov %gs:0x0,%eax
80490aa: 90[ ]+nop *
- 80490ab: 8d 74 26 00[ ]+lea 0x0\(%esi\),%esi
+ 80490ab: 8d 74 26 00[ ]+lea 0x0\(%esi,,1\),%esi
80490af: 90[ ]+nop *
80490b0: 90[ ]+nop *
80490b1: 8d 90 40 f0 ff ff[ ]+lea 0xfffff040\(%eax\),%edx
--- binutils/opcodes/i386-dis.c.sib 2005-01-13 09:41:31.000000000 -0800
+++ binutils/opcodes/i386-dis.c 2005-01-14 13:33:42.625890827 -0800
@@ -3191,10 +3191,8 @@ OP_E (int bytemode, int sizeflag)
{
havesib = 1;
FETCH_DATA (the_info, codep + 1);
+ scale = (*codep >> 6) & 3;
index = (*codeA.A2A.A2.F22B 2EAA2+EE/F/ -+A . .*2A6FF2F.. .-.+.A21A.A2B.E.A+2A..F.F.2A2AF/E.F.EAEB2FB2AE/AE/EFFA3E..AE.E3EA2A2A2E/AA2FA2.A+..
"#$ $#$$!$449K8KLP P#A.-..A..@..A2AA..A..A2.A.E.E.A.E.A22E /2AE./E2.E F.2A.-....
.A2BE3F2+. .....E.A+2A.A2>2>.2A.EB2A3A>2.F2A3E2AF.3A3A2BE.E2.E.A32A2AE2AE3A3A3AE3AF.3EA2BA...-.
#!#(4(G89KLL PP ..A.A2.A+.>-.A2A.@2A.2.A2>2A.A2A...E. 23E.2EAE.B .E.E/..AA.+ .
+ +2.E+. .@.A...2A..A.A2...A.E32F/E/EE/.A2A3A3.EA2A2BE2B2AE+E+EB2>E.FA3AF.FE33AF.EA3EF..A.+.+
## #!8$849K5K LLLLLLLL .-.A..>-A-.2A.+1A...E.A+E.A.E.AA-.A2 23E/E.FB2 B2F.B.E2A.+-.. .
..+ A-....E.>2A.2A.A-A.A.F/A3A/E//E+E.FA3EF.3AEA2B2AE/AA.E.EF1AF2BE3AE3AEB6AF.EA3AFA.AA.
##$3!84(4LK9L PLP ...+.A..+A.>.A2A.A2A.A2A.E.A.E.+A. .F2FE3A2 A . .*2A6FF2F.. .-.+.A21A.A2B.E.A+2A..F.F.2A2AF/E.F.EAEB2FB2AE/AE/EFFA3E..AE.E3EA2A2A2E/AA2FA2.A+..
"#$ $#$$!$449K8KLP P#A.-..A..@..A2AA..A..A2.A.E.E.A.E.A22E /2AE./E2.E F.2A.-....
.A2BE3F2+. .....E.A+2A.A2>2>.2A.EB2A3A>2.F2A3E2AF.3A3A2BE.E2.E.A32A2AE2AE3A3A3AE3AF.3EA2BA...-.
#!#(4(G89KLL PP ..A.A2.A+.>-.A2A.@2A.2.A2>2A.A2A...E. 23E.2EAE.B .E.E/..AA.+ .
+ +2.E+. .@.A...2A..A.A2...A.E32F/E/EE/.A2A3A3.EA2A2BE2B2AE+E+EB2>E.FA3AF.FE33AF.EA3EF..A.+.+
## #!8$849K5K LLLLLLLL .-.A..>-A-.2A.+1A...E.A+E.A.E.AA-.A2 23E/E.FB2 B2F.B.E2A.+-.. .
..+ A-....E.>2A.2A.A-A.A.F/A3A/E//E+E.FA3EF.3AEA2B2AE/AA.E.EF1AF2BE3AE3AEB6AF.EA3AFA.AA.
##$3!84(4LK9L PLP ...+.A..+A.>.A2A.A2A.A2A.E.A.E.+A. .F2FE3A2 2A2B2E.F.E2E..>.+ + . ..AA.E.E2A.A2+E2A.A2A2A3A2A.AA.A.A2BE3A3E.F2B2FE3A3.E2E/EB2EE3EB6BE2F2E/E.E.J3A2A.*
#$$4(GL8=KL P 3.A..E.+A.A.A-E.A2..A.A.A2A.E.A.2E .2E/E3E2 FB3A2E/A3.E33F.A... - . .*.>2.A.E/A.A.A.2>3A.A/A2B2B.E.+A+A23AEB3EAE.E>FAFA2EAFEFE.EFAFA3EF.JB2B2E/EAF.F.A.A.*
p >> 3) & 7;
- if (mode_64bit || index != 0x4)
- /* When INDEX == 0x4 in 32 bit mode, SCALE is ignored. */
- scale = (*codep >> 6) & 3;
base = *codep & 7;
USED_REX (REX_EXTY);
USED_REX (REX_EXTZ);
@@ -3316,7 +3314,20 @@ OP_E (int bytemode, int sizeflag)
oappend (mode_64bit && (sizeflag & AFLAG)
? names64[index] : names32[index]);
}
- if (scale != 0 || (!intel_syntax && index != 4))
+ else if (!intel_syntax
+ && havebase
+ && (scale != 0
+ || ((base & 7) != 4
+ && (base & 7) != 5)))
+ {
+ *obufp++ = separator_char;
+ *obufp = '\0';
+ }
+ if (scale != 0
+ || (!intel_syntax && index != 4)
+ || (index == 4
+ && (base & 7) != 4
+ && (base & 7) != 5))
{
*obufp++ = scale_char;
*obufp = '\0';
. $$#84488HKLL PPP ...A-A2-A...>2A.E.A.A2..E.A.E.A A/2AE. 3A2.F.F-E.E/2A33E....+ - + A...E.E3E.A2A..A2A2A2E.B.A.A+A....E.3A2A3.E2AF.AF.E.FA2A3>EFB2EB2BE3E3E/E.F3E3A2A...-
$ $K848KL8L L .-A.A+A.+A.D...A.2+2..AE.A2A.2 E.2E/2 22F+2BF2B2A3E/EB2.F/E@....A. .2.+2A.F2A/A...A2/EA...A3AE...A.E..E.FE/E3EE3AF.E3EAE3A3E/E2B.EE.FF2EB3A3E/E2B3A3A2AA. $#$4$88G9LLL L ......-A...A.@2+A+E.@...A.E.A 2.A2A 2EB2.EA2./E.3A3>22B2.A3A.E+-... . .+.AE..A.F.E.A2A.EA..A2A2A3.A.E.A2.E2A2BE3EF3JB2ABEEB3AF.BEAE2AE.F.EBJ.F3A3A2B.EB.A....A
# #$$8G494LK LL ..A-.>.A-A...A..E.+A..E.AA A.AA 3.E/2.B2.-AE/E2A.22?2.A32F.-E.+@.+. @2A..A.2F.A2A.B..A..A.A2/E2A.A2A1A//A2B2BE/2.F.F.E3EJA7AE2A2AF.EF.J/E/F2FBA3A2F.AE.A.A*
$ 84888LPLKP PPPPPPPP .....@...+2@...@.+2A..A.A. .... ..E3.E,E2B.E2AE/E2A2B2.A.E/2E3.E..@.A...+...A2.A.A.2>3A.E..>.2E.B2/E.23A2B.EA2B2E3EFEE3A2E/EB2FFB2A3AF.FE3EFA3F2F..AF.B.A2.A.A..On Fri, Jan 14, 2005 at 11:29:18AM +1030, Alan Modra wrote:
> On Thu, Jan 13, 2005 at 04:26:59PM -0800, H. J. Lu wrote:
> > If it is an optimization, there shouldn't be a warning.
>
> No, whether we warn or not is an entirely separate matter to whether we
> optimize.
>
> > I think it
> > may be useful to turn "leal 0xf(%eax,1), %eax" into "8d 44 20 0f"
> > Gcc/ld use
> >
> > leal foo(%reg), %eax; call ___tls_get_addr; nop
> >
> > today for TLS optimization. With the change, we can use
> >
> > leal foo(%reg,1), %eax; call ___tls_get_addr;
>
> Hmm. So that you generate a larger instruction on purpose? Wanted for
> the space needed with some of the tls transformations, I expect.
>
> OK, that is a valid reason to support encoding of the instruction
> that way. You still should warn for scale factors other than 1,
> because it's easy to forget the comma in (,%reg,2) where you really
> do want the register to be scaled.
>
> > Then it should display
> >
> > 8b 04 23 mov (%ebx,1),%eax
>
I decided to use (%ebx,,1) for this and adjusted assembler to accept
it. You will get warnings for (%ebx,1) as before. It will be easier
to check if assembler takes (%ebx,,1).
BTW, I didn't change the Intel syntax since I don't know enough
about it.
H.J.
-----
gas/
2005-01-14 H.J. Lu <hongjiu.lu@intel.com>
PR 658
* config/tc-i386.c (SCALE1_WHEN_NO_INDEX): Removed.
(_i386_insn): Add empty_index_reg.
(build_modrm_byte): Use SIB if empty_index_reg is not 0.
(i386_scale): Don't warn scale factor without index register if
empty_index_reg is not 0.
(i386_operand): Set empty_index_reg 1 if the index register is
"".
gas/testsuite/
2005-01-14 H.J. Lu <hongjiu.lu@intel.com>
PR 658
* gas/i386/sib.d: Updated.
* gas/i386/sib.s: Likewise.
* gas/i386/ssemmx2.d: Likewise.
ld/testsuite/
2005-01-14 H.J. Lu <hongjiu.lu@intel.com>
PR 658
* ld-i386/tlsbin.dd: Updated.
opcodes/
2005-01-14 H.J. Lu <hongjiu.lu@intel.com>
PR 658
* 386-dis.c (OP_E): Undo the 2005-01-12 change. Display scale
for SIB with INDEX == 4.
--- binutils/gas/config/tc-i386.c.sib 2005-01-14 11:27:06.000000000 -0800
+++ binutils/gas/config/tc-i386.c 2005-01-14 12:25:45.624584751 -0800
@@ -43,14 +43,6 @@
#define INFER_ADDR_PREFIX 1
#endif
-#ifndef SCALE1_WHEN_NO_INDEX
-/* Specifying a scale factor besides 1 when there is no index is
- futile. eg. `mov (%ebx,2),%al' does exactly the same as
- `mov (%ebx),%al'. To slavishly follow what the programmer
- specified, set SCALE1_WHEN_NO_INDEX to 0. */
-#define SCALE1_WHEN_NO_INDEX 1
-#endif
-
#ifndef DEFAULT_ARCH
#define DEFAULT_ARCH "i386"
#endif
@@ -162,6 +154,8 @@ struct _i386_insn
const reg_entry *index_reg;
unsigned int log2_scale_factor;
+ int empty_index_reg;
+
/* SEG gives the seg_entries of this insn. They are zero unless
explicit segment overrides are given. */
const seg_entry *seg[2];
@@ -3006,11 +3000,9 @@ build_modrm_byte ()
Any base register besides %esp will not use the
extra modrm byte. */
i.sib.index = NO_INDEX_REGISTER;
-#if !SCALE1_WHEN_NO_INDEX
/* Another case where we force the second modrm byte. */
- if (i.log2_scale_factor)
+ if (i.empty_index_reg)
i.rm.regmem = ESCAPE_TO_TWO_BYTE_ADDRESSING;
-#endif
}
else
{
@@ -3970,13 +3962,13 @@ i386_scale (scale)
input_line_pointer = save;
return NULL;
}
- if (i.log2_scale_factor != 0 && i.index_reg == 0)
+ if (i.log2_scale_factor != 0
+ && i.index_reg == 0
+ && i.empty_index_reg == 0)
{
as_warn (_("scale factor of %d without an index register"),
1 << i.log2_scale_factor);
-#if SCALE1_WHEN_NO_INDEX
i.log2_scale_factor = 0;
-#endif
}
scale = input_line_pointer;
input_line_pointer = save;
@@ -4430,6 +4422,12 @@ i386_operand (operand_string)
as_bad (_("bad register name `%s'"), base_string);
return 0;
}
+ else if (*base_string == ',' && i.base_reg)
+ {
+ /* Check for empty index reg. */
+ base_string++;
+ i.empty_index_reg = 1;
+ }
/* Check for scale factor. */
if (*base_string != ')')
--- binutils/gas/testsuite/gas/i386/sib.d.sib 2005-01-12 11:12:51.000000000 -0800
+++ binutils/gas/testsuite/gas/i386/sib.d 2005-01-14 12:43:29.131911163 -0800
@@ -6,10 +6,14 @@
Disassembly of section .text:
0+000 <foo>:
- 0: 8b 04 23 [ ]*mov [ ]*\(%ebx\),%eax
- 3: 8b 04 63 [ ]*mov [ ]*\(%ebx\),%eax
- 6: 8b 04 a3 [ ]*mov [ ]*\(%ebx\),%eax
- 9: 8b 04 e3 [ ]*mov [ ]*\(%ebx\),%eax
- c: 90 [ ]*nop [ ]*
- d: 90 [ ]*nop [ ]*
- ...
+ 0: 8b 03 [ ]*mov [ ]*\(%ebx\),%eax
+ 2: 8b 04 23 [ ]*mov [ ]*\(%ebx,,1\),%eax
+ 5: 8b 04 63 [ ]*mov [ ]*\(%ebx,,2\),%eax
+ 8: 8b 04 a3 [ ]*mov [ ]*\(%ebx,,4\),%eaxxebx,,xxxxxx JI FIOIJIJJIIJIJIFN FIOIJIJJIIJIJIFN
2JEOJJIJI3 2JJIJJIJIJIJIJIJ FIOIJIJJIIJIJIFN ##3$84889KLLL
EIJIJEJIE3E JIJIJEJIJEIJ2#EJIJEJJIJNJIJI2 /IJIJJIIJ2 JIIIJIJFJIJIJIJIJ #JJIJIJIJ"FJIJIIJNJIFNFNJI" IJIJIJNIJOIJIJIJ" # 3$$484HKL8L