[Bug c/60036] New: Spurious signedness conversion warning with relational operator

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

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60036

            Bug ID: 60036
           Summary: Spurious signedness conversion warning with relational
                    operator
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: chengniansun at gmail dot com

Gcc-trunk emits a signedness conversion warning for the statement "f ^= fn1() >
a;". However, as the value of "fn1() > a" is either 1 or 0, the warning is not
true. 

Moreover, Gcc-4.8 and 4.7 do not output this warning. And if I change the
statement to "f = f ^ (fn1() > a);", gcc-trunk does not emit this warning,
either.



$: cat conversion-for-boolean.c
extern int fn1();
unsigned fn(int a) {
  unsigned f = 9;
  f ^= fn1() > a;
  return f;
}

$: gcc-trunk -c -Wconversion -std=c11 conversion-for-boolean.c
conversion-for-boolean.c: In function ‘fn’:
conversion-for-boolean.c:4:5: warning: conversion to ‘unsigned int’ from ‘int’
may change the sign of the result [-Wsign-conversion]
   f ^= fn1() > a;
     ^
$: gcc-4.8 -c -Wconversion -std=c11 conversion-for-boolean.c
$: gcc-4.7 -c -Wconversion -std=c11 conversion-for-boolean.c
$: gcc-trunk --version
gcc-trunk (GCC) 4.9.0 20140131 (experimental)
Copyright (C) 2014 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
>From gcc-bugs-return-442340-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org Mon Feb 03 01:40:36 2014
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From: "alexa.gerancho at hushmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/58854] [4.8 regression] "sub sp, fp, #40" hoisted above frame accesses
Date: Mon, 03 Feb 2014 01:40:00 -0000
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http://gcc.gnu.org/bugzilla/show_bug.cgi?idX854

Alexa <alexa.gerancho at hushmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |alexa.gerancho at hushmail dot com

--- Comment #13 from Alexa <alexa.gerancho at hushmail dot com> ---
*** Bug 260998 has been marked as a duplicate of this bug. ***
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Marked for reference. Resolved as fixed @bugzilla.