[Bug middle-end/38999] New: [4.2/4.3/4.4 Regression] Extra overflow warning in 32-bit HWI compiler

[jakub at gcc dot gnu dot org]

+++ This bug was initially created as a clone of Bug #38934 +++

This failure is not "worked around" by FRE unlike 38932.

/* { dg-do compile } */
/* { dg-options "-O2 --std=gnu99" } */

/* This variable needed only to work around earlier optimizations than VRP.  */
unsigned char g;

extern void abort();

void f (long long int p)
{
  g = 255;
  /* { dg-warning "constant is" "" { target *-*-* } 14 } */
  /* { dg-warning "overflow" "" { target *-*-* } 14 } */
  if (p >= -9223372036854775808LL - (signed char) g)
    p = 1;

  if (p)
    abort ();
}

3.2.x issued just one warning both in 32-bit HWI i386 gcc and x86_64 -m32 gcc,
haven't checked 3.3, 3.4 and later issues one extra warning in 32-bit HWI
compilation.


-- 
           Summary: [4.2/4.3/4.4 Regression] Extra overflow warning in 32-
                    bit HWI compiler
           Product: gcc
           Version: 4.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: jakub at gcc dot gnu dot org
GCC target triplet: i686-pc-linux-gnu
 BugsThisDependsOn: 38934


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38999