[Bug c/61903] New: signed integer overflow in expmed.c store_fixed_bit_filed_1

[Bug c/61903] New: signed integer overflow in expmed.c store_fixed_bit_filed_1

[zeccav at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61903

            Bug ID: 61903
           Summary: signed integer overflow in expmed.c
                    store_fixed_bit_filed_1
           Product: gcc
           Version: 4.9.1
            Status: UNCONFIRMED
          Severity: minor
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: zeccav at gmail dot com

Compiling testsuite code pr28045.c the sanitizer claims that a signed integer
overflow occurs at expmed.c:1071
"../../gcc-4.9.1/gcc/expmed.c:1071:41: runtime error: signed integer overflow:
-9223372036854775808 + -1 cannot be represented in type 'long int'"
The offending instruction is
"v &= ((HOST_WIDE_INT) 1 << bitsize) - 1;"
This is in store_fixed_bit_field_1 on x86-64.

[Bug c/61903] signed integer overflow in expmed.c store_fixed_bit_filed_1

[zeccav at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61903

--- Comment #1 from Vittorio Zecca <zeccav at gmail dot com> ---
Same runtime error at line 1076 of expmed.c
"&& v == ((HOST_WIDE_INT) 1 << bitsize) - 1)"
compiling pr28045.c

[Bug middle-end/61903] signed integer overflow in expmed.c store_fixed_bit_filed_1

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61903

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2014-07-25
          Component|c                           |middle-end
     Ever confirmed|0                           |1

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
      if (bitsize < HOST_BITS_PER_WIDE_INT)
        v &= ((HOST_WIDE_INT) 1 << bitsize) - 1;

Should be an easy fix to change HOST_WIDE_INT to unsigned HOST_WIDE_INT.

[Bug middle-end/61903] signed integer overflow in expmed.c store_fixed_bit_filed_1

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61903

--- Comment #3 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Author: mpolacek
Date: Mon Sep  1 09:18:43 2014
New Revision: 214781

URL: https://gcc.gnu.org/viewcvs?rev=214781&root=gcc&view=rev
Log:
    PR middle-end/61903
    * expmed.c (store_fixed_bit_field_1): Shift UHWI 1 instead of HWI 1.
    Change the type of V to unsigned HOST_WIDE_INT.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/expmed.c

[Bug middle-end/61903] signed integer overflow in expmed.c store_fixed_bit_filed_1

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61903

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
                 CC|                            |mpolacek at gcc dot gnu.org
         Resolution|---                         |FIXED
           Assignee|unassigned at gcc dot gnu.org      |mpolacek at gcc dot gnu.org
   Target Milestone|---                         |5.0

--- Comment #4 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Fixed.