target/8340: [mainline regression] ICE on x86 inline asm w/ -fPIC

target/8340: [mainline regression] ICE on x86 inline asm w/ -fPIC

[glen]

>Number:         8340
>Category:       target
>Synopsis:       [mainline regression] ICE on x86 inline asm w/ -fPIC
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          ice-on-legal-code
>Submitter-Id:   net
>Arrival-Date:   Thu Oct 24 09:56:02 PDT 2002
>Closed-Date:
>Last-Modified:
>Originator:     Glen Nakamura
>Release:        gcc version 3.3 20021023 (experimental)
>Organization:
>Environment:
i686-pc-linux-gnu
>Description:
asm.c: In function `foo':
asm.c:5: internal compiler error: asm clobber conflict with output operand
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://www.gnu.org/software/gcc/bugs.html> for instructions.
>How-To-Repeat:
gcc -fPIC -c asm.c
>Fix:
(work-around) remove "static" from:
static int a;
>Release-Note:
>Audit-Trail:
>Unformatted:
----gnatsweb-attachment----
Content-Type: application/octet-stream; name="asm.c"
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename="asm.c"

aW50CmZvbyAoKQp7CiAgc3RhdGljIGludCBhOwogIF9fYXNtX18gX192b2xhdGlsZV9fICgKICAg
ICJ4b3JsICUlZWJ4LCAlJWVieFxuIgogICAgIm1vdmwgJSVlYngsICUwXG4iCiAgICA6ICI9bSIg
KGEpCiAgICA6CiAgICA6ICIlZWJ4IgogICk7CiAgcmV0dXJuIGE7Cn0K

Re: target/8340: [mainline regression] ICE on x86 inline asm w/ -fPIC

[rth]

Synopsis: [mainline regression] ICE on x86 inline asm w/ -fPIC

State-Changed-From-To: open->analyzed
State-Changed-By: rth
State-Changed-When: Fri Oct 25 16:01:14 2002
State-Changed-Why:
    Yes, this code is illegal.  This is common enough that we should
    probably arrange for expand_asm_operands to complain if the
    pic register is clobbered.

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=8340

Re: target/8340: [mainline regression] ICE on x86 inline asm w/ -fPIC

[Glen Nakamura]

The following reply was made to PR target/8340; it has been noted by GNATS.

From: Glen Nakamura <glen@imodulo.com>
To: gcc-gnats@gcc.gnu.org, gcc-bugs@gcc.gnu.org
Cc:  
Subject: Re: target/8340: [mainline regression] ICE on x86 inline asm w/ -fPIC
Date: Thu, 24 Oct 2002 07:40:38 -1000

 http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=8340
 
 On second thought, maybe this really is invalid code when compiled w/ -fPIC?
 gcc-3.2.1 silently generates the following incorrect code:
 
 00000000 <foo>:
    0:	55                   	push   %ebp
    1:	89 e5                	mov    %esp,%ebp
    3:	53                   	push   %ebx
    4:	e8 00 00 00 00       	call   9 <foo+0x9>
    9:	5b                   	pop    %ebx
    a:	81 c3 03 00 00 00    	add    $0x3,%ebx
   10:	31 db                	xor    %ebx,%ebx
   12:	89 9b 00 00 00 00    	mov    %ebx,0x0(%ebx)
   18:	8b 83 00 00 00 00    	mov    0x0(%ebx),%eax
   1e:	5b                   	pop    %ebx
   1f:	5d                   	pop    %ebp
   20:	c3                   	ret    
 
 A better error message would be nice, especially for gcc-3.2.1,
 but this isn't a high priority since the code seems invalid to me.
 
 - glen