[Bug c/30936] New: const attribute in nanf prototype causes gcc not producing correct code.

[filippo dot arcidiacono at gmail dot com]

Being nanf declared using const attribute, sh4-linux-gcc (4.1.1) doesn't
produce 
the code to call the nanf function.
Removing the 'const' attribute the generated code works fine.
Using gcc (3.4.3) Red Hat EL4 the test runs fine.


-- 
   Summary: const attribute in nanf prototype causes gcc not
producing correct code.
   Product: gcc
   Version: 4.1.1
Status: UNCONFIRMED
  Severity: normal
  Priority: P3
 Component: c
AssignedTo: unassigned at gcc dot gnu dot org
    ReportedBy: filippo dot arcidiacono at gmail dot com
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: sh4-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30936

[Bug c/30936] const attribute in nanf prototype causes gcc not producing correct code.

[filippo dot arcidiacono at gmail dot com]

--- Comment #1 from filippo dot arcidiacono at gmail dot com  2007-02-23 
15:43 ---
Created an attachment (id=13100)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=13100&action=view)
simple test case exploiting gcc bug

compiled with the following command:
> sh4-linux-gcc nanf-test.c -D_GNU_SOURCE -o nanf-test -lm


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30936

[Bug c/30936] const attribute in nanf prototype causes gcc not producing correct code.

[filippo dot arcidiacono at gmail dot com]

--- Comment #3 from filippo dot arcidiacono at gmail dot com  2007-02-26 
08:08 ---
Created an attachment (id=13111)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=13111&action=view)
prerprocessed file of nanf-test.c

In  attach you can find the preprocessed file nanf-test.i of nanf-test.c.
It contains the nanf prototype, declared by bits/mathcalls.h included by math.h
header file.
Using -Wall option I doesn't obtain any warning.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30936

[Bug target/30936] const attribute in nanf prototype causes gcc not producing correct code.

[filippo dot arcidiacono at gmail dot com]

--- Comment #5 from filippo dot arcidiacono at gmail dot com  2007-02-26 
09:29 ---
Created an attachment (id=13112)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=13112&action=view)
assembler code of nanf-test.c

Following a piece of the objdump of the nanf-test:
:
:
int
main (void)
{
   0:   e6 2f   mov.l   r14,@-r15
   2:   22 4f   sts.l   pr,@-r15
   4:   f8 7f   add #-8,r15
   6:   f3 6e   mov r15,r14
  int op;

  op = (nanf ("") != nanf ("") );
   8:   e3 62   mov r14,r2
   a:   c8 72   add #-56,r2
   c:   00 e1   mov #0,r1
   e:   1f 12   mov.l   r1,@(60,r2)
  if (!op) {
  10:   e3 61   mov r14,r1
  12:   c8 71   add #-56,r1
  14:   1f 51   mov.l   @(60,r1),r1
  16:   18 21   tst r1,r1
  18:   08 8b   bf  2c 
printf ("Test NAN Failed!\n");
  1a:   09 d1   mov.l   40 ,r1   ! 0x0 
  1c:   13 64   mov r1,r4
  1e:   09 d1   mov.l   44 ,r1   ! 0x0 
  20:   0b 41   jsr @r1
  22:   09 00   nop 
return (1);
  24:   01 e1   mov #1,r1
  26:   12 2e   mov.l   r1,@r14
  28:   02 a0   bra 30 
  2a:   09 00   nop 
  }
:
:
Note that I using sh4 architecture.
In attach you can find the nanf-test.s that doesn't contains any reference 
to nanf symbol.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30936

[Bug target/30936] __builtin_nanf("") != __builtin_nanf("") is false for sh4-linux-gnu

[filippo dot arcidiacono at gmail dot com]

--- Comment #7 from filippo dot arcidiacono at gmail dot com  2007-02-26 
13:01 ---
> is wrong, it should be instead:
> mov #1, r1

OK!
This is what I get if I use __builtin_nanf() instead of nanf.
But using nanf there isn't any undefined nanf symbol in the obiect
generated, as expected, as well as happens also with gcc (3.4.3).


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30936