[Bug inline-asm/39590] New: inline asm %z on amd64 says "ll" instead of "q"

[Bug inline-asm/39590] New: inline asm %z on amd64 says "ll" instead of "q"

[felix-gcc at fefe dot de]

I am trying to write an inline asm statement that atomically adds a number to a
memory variable.  Here's what I came up with:

#define atomic_add(mem,val) asm volatile ("lock; add%z0 %1, %0": "+m" (mem):
"ir" (val))

This appears to work fine on x86, but in 64-bit mode %z returns "ll" instead of
"q" for 64-bit values like size_t, and thus the assembler complains like this:

t.c:53: Error: no such instruction: `addll $3,x.5802(%rip)'

If I understand %z correctly, this is exactly what it is meant for... right?
Please make it return "q" in this case.


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           Summary: inline asm %z on amd64 says "ll" instead of "q"
           Product: gcc
           Version: 4.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: inline-asm
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: felix-gcc at fefe dot de
 GCC build triplet: x86_64-unknown-linux-gnu
  GCC host triplet: x86_64-unknown-linux-gnu
GCC target triplet: x86_64-unknown-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39590

[Bug inline-asm/39590] inline asm %z on amd64 says "ll" instead of "q"

[hjl dot tools at gmail dot com]

------- Comment #1 from hjl dot tools at gmail dot com  2009-03-30 19:19 -------
Please provide a testcase.


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hjl dot tools at gmail dot com changed:

           What    |Removed                     |Added
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                 CC|                            |hjl dot tools at gmail dot
                   |                            |com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39590

[Bug inline-asm/39590] inline asm %z on amd64 says "ll" instead of "q"

[felix-gcc at fefe dot de]

------- Comment #2 from felix-gcc at fefe dot de  2009-03-30 19:54 -------
Uh, I did.  Use the macro like this:

int foo=2;
atomic_add(foo,3);

then try size_t as type of foo and compile on x86_64.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39590

[Bug inline-asm/39590] inline asm %z on amd64 says "ll" instead of "q"

[hjl dot tools at gmail dot com]

------- Comment #3 from hjl dot tools at gmail dot com  2009-03-30 19:59 -------
(In reply to comment #2)
> Uh, I did.  Use the macro like this:
> 
> int foo=2;
> atomic_add(foo,3);
> 
> then try size_t as type of foo and compile on x86_64.
> 

That is not a testcase. I need a valid C source code, which
I can compile.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39590

[Bug inline-asm/39590] inline asm %z on amd64 says "ll" instead of "q"

[felix-gcc at fefe dot de]

------- Comment #4 from felix-gcc at fefe dot de  2009-03-30 20:27 -------
#include <stddef.h>

#define atomic_add(mem,val) asm volatile ("lock; add%z0 %1, %0": "+m" (mem):
"ir" (val))

int main() {
  size_t foo;
  atomic_add(foo,23);
}


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39590

[Bug inline-asm/39590] inline asm %z on amd64 says "ll" instead of "q"

[hjl dot tools at gmail dot com]

------- Comment #5 from hjl dot tools at gmail dot com  2009-03-30 21:07 -------
'z' is for x87 insns. You have to check size of size_t and use
proper suffix in your code.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39590

[Bug inline-asm/39590] inline asm %z on amd64 says "ll" instead of "q"

[felix-gcc at fefe dot de]

------- Comment #6 from felix-gcc at fefe dot de  2009-03-30 22:10 -------
> 'z' is for x87 insns.

Uh, what?!  Let me quote the relevant "documentation"
(gcc/config/i386/i386.md):

;; The special asm out single letter directives following a '%' are:
;; 'z' mov%z1 would be movl, movw, or movb depending on the mode of
;;     operands[1].

No mention of floating point.

> You have to check size of size_t and use
> proper suffix in your code.

No.  The whole point of %z is that you can write asm statements in a way that
does not specify the argument size explicitly in the statement.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39590

[Bug inline-asm/39590] inline asm %z on amd64 says "ll" instead of "q"

[hjl dot tools at gmail dot com]

------- Comment #7 from hjl dot tools at gmail dot com  2009-03-31 01:28 -------
(In reply to comment #6)
> > 'z' is for x87 insns.
> 
> Uh, what?!  Let me quote the relevant "documentation"
> (gcc/config/i386/i386.md):
> 
> ;; The special asm out single letter directives following a '%' are:
> ;; 'z' mov%z1 would be movl, movw, or movb depending on the mode of
> ;;     operands[1].
> 

This was written before x86-64 and movq is mentioned here. 64bit is for
fildll/fildq. I don't know if all x86-64 assemblers support fildq.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39590

[Bug inline-asm/39590] inline asm %z on amd64 says "ll" instead of "q"

[hjl dot tools at gmail dot com]

------- Comment #8 from hjl dot tools at gmail dot com  2009-03-31 22:42 -------
Darwin assembler and GNU assembler support fildq (%rax). But
Solaris assembler doesn't. Only fildll works with all assemblers.
We can't generate the 'q' suffix for "%z".


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hjl dot tools at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ubizjak at gmail dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39590

[Bug inline-asm/39590] inline asm %z on amd64 says "ll" instead of "q"

[hjl dot tools at gmail dot com]

------- Comment #9 from hjl dot tools at gmail dot com  2009-04-01 01:08 -------
I don't think it will hurt to generate fildq in 64bit if
assembler supports it.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39590

[Bug inline-asm/39590] inline asm %z on amd64 says "ll" instead of "q"

[hjl dot tools at gmail dot com]

------- Comment #10 from hjl dot tools at gmail dot com  2009-04-01 19:09 -------
A patch is posted at

http://gcc.gnu.org/ml/gcc-patches/2009-04/msg00112.html


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hjl dot tools at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                URL|                            |http://gcc.gnu.org/ml/gcc-
                   |                            |patches/2009-
                   |                            |04/msg00112.html
   Target Milestone|---                         |4.5.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39590

[Bug inline-asm/39590] inline asm %z on amd64 says "ll" instead of "q"

[pinskia at gcc dot gnu dot org]

------- Comment #11 from pinskia at gcc dot gnu dot org  2009-04-16 18:34 -------
Stop setting the target milestone unless it is a regression.


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pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.5.0                       |---


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39590

[Bug inline-asm/39590] inline asm %z on amd64 says "ll" instead of "q"

[uros at gcc dot gnu dot org]

------- Comment #12 from uros at gcc dot gnu dot org  2009-04-25 08:11 -------
Subject: Bug 39590

Author: uros
Date: Sat Apr 25 08:10:51 2009
New Revision: 146761

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=146761
Log:
        PR target/39590
        * configure.ac (HAVE_AS_IX86_FILDQ): On x86 targets check whether
        the configured assembler supports fildq and fistpq mnemonics.
        (HAVE_AS_IX86_FILDS): Rename from HAVE_GAS_FILDS_FISTS.
        * configure: Regenerated.
        * config.in: Ditto.

        * config/i386/i386.c (print_operand): Handle 'Z'.
        ['z']: Remove handling of special fild/fist suffixes.
        (output_fix_trunc): Use '%Z' to output suffix of fist{,p,tp} insn.
        * config/i386/i386.md (*floathi<mode>2_i387): Use '%Z' to output
        suffix of fild insn.
        (*floatsi<mode>2_vector_mixed): Ditto.
        (*float<SSEMODEI24:mode><MODEF:mode>2_mixed_interunit): Ditto.
        (*float<SSEMODEI24:mode><MODEF:mode>2_mixed_nointerunit): Ditto.
        (*float<SSEMODEI24:mode><X87MODEF:mode>2_i387_with_temp): Ditto.
        (*float<SSEMODEI24:mode><X87MODEF:mode>2_i387): Ditto.
        * config/i386/gas.h (GAS_MNEMONICS): Remove.


Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/config.in
    trunk/gcc/config/i386/gas.h
    trunk/gcc/config/i386/i386.c
    trunk/gcc/config/i386/i386.md
    trunk/gcc/configure
    trunk/gcc/configure.ac


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39590

[Bug inline-asm/39590] inline asm %z on amd64 says "ll" instead of "q"

[ubizjak at gmail dot com]

------- Comment #13 from ubizjak at gmail dot com  2009-04-25 08:23 -------
Fixed for 4.5.0.


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ubizjak at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|---                         |4.5.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39590