[Bug c/60083] Duplicate conversion warnings from negative integer to unsigned type (gcc-4.3 emits only one warning)

["chengniansun at gmail dot com" <gcc-bugzilla@gcc.gnu.org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60083

--- Comment #1 from Chengnian Sun <chengniansun at gmail dot com> ---
I think the following case is similar to the reported case. The only difference
is the message content. The following case also triggers "gcc -O0" to emit two
duplicate warnings. But "gcc -O1" emits only one warning.

$: cat s.c
extern short fn2(short, short);
unsigned long g;
void fn1() {
  int const l = 0;
  fn2(((g = l != 0) < 10LL) | 91608LL, 0);
}
$: gcc-trunk -c -Wconversion -std=c99 s.c
s.c: In function ‘fn1’:
s.c:5:7: warning: conversion to ‘short int’ alters ‘long long int’ constant
value [-Wconversion]
   fn2(((g = l != 0) < 10LL) | 91608LL, 0);
       ^
s.c:5:7: warning: conversion to ‘short int’ alters ‘long long int’ constant
value [-Wconversion]
$: gcc-trunk -c -Wconversion -std=c99 s.c -O1
s.c: In function ‘fn1’:
s.c:5:7: warning: conversion to ‘short int’ from ‘long long int’ may alter its
value [-Wconversion]
   fn2(((g = l != 0) < 10LL) | 91608LL, 0);
       ^
$:
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From: "mpolacek at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c/60083] Duplicate conversion warnings from negative integer to unsigned type (gcc-4.3 emits only one warning)
Date: Fri, 07 Feb 2014 21:22:00 -0000
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http://gcc.gnu.org/bugzilla/show_bug.cgi?id`083

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2014-02-07
                 CC|                            |mpolacek at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #2 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Yeah, I bet we'll have tons of those ;/.