optimization/7335: Sparc: ICE in verify_wide_reg (flow.c:557) with long double and optimization

optimization/7335: Sparc: ICE in verify_wide_reg (flow.c:557) with long double and optimization

[wolfgang.bangerth]

>Number:         7335
>Category:       optimization
>Synopsis:       Sparc: ICE in verify_wide_reg (flow.c:557) with long double and optimization
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Jul 17 02:26:03 PDT 2002
>Closed-Date:
>Last-Modified:
>Originator:     Wolfgang Bangerth
>Release:        gcc3.1, gcc3.1.1 pre of 20020624
>Organization:
>Environment:
sparc-sun-solaris2.8/9
>Description:
gcc ICEs upon the following (simple, common) code when compiling with -O1 on sparc machines:
-------------------------------------------------
double* copy(long double* first, long double* last, double* result)
{
  int n;
  for (n = last - first; n > 0; --n) {
    *result = *first;
    ++first;
    ++result;
  }
  return result;
}

void f()
{
  long double *p1, *p2;
  double *p3;
  copy (p1, p2, p3);
  p3 = copy (p1, p2, p3);
};
----------------------------------------------------

deal.II/base> ~/bin/sparc-sun-solaris2.9/bin/gcc -v
Reading specs from /home/atlas2/wolf/bin/sparc-sun-solaris2.9/bin/../lib/gcc-lib/sparc-sun-solaris2.9/3.1.1/specs
Configured with: ../gcc-20020624/configure --prefix=/home/people/wolf/bin/sparc-sun-solaris2.9 --enable-languages=c,c++
Thread model: posix
gcc version 3.1.1 20020624 (prerelease)

deal.II/base> ~/bin/sparc-sun-solaris2.9/bin/gcc -O1 -c t.c
t.c: In function `copy':
t.c:10: Internal compiler error in verify_wide_reg, at flow.c:557
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://www.gnu.org/software/gcc/bugs.html> for instructions.
>How-To-Repeat:

>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted:

Re: optimization/7335: Sparc: ICE in verify_wide_reg (flow.c:557) with long double and optimization

[davem]

Synopsis: Sparc: ICE in verify_wide_reg (flow.c:557) with long double and optimization

State-Changed-From-To: analyzed->closed
State-Changed-By: davem
State-Changed-When: Thu Sep 26 21:18:00 2002
State-Changed-Why:
    See audit trail.

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=7335

Re: optimization/7335: Sparc: ICE in verify_wide_reg (flow.c:557) with long double and optimization

[davem]

Synopsis: Sparc: ICE in verify_wide_reg (flow.c:557) with long double and optimization

Responsible-Changed-From-To: unassigned->davem
Responsible-Changed-By: davem
Responsible-Changed-When: Thu Sep 26 15:54:15 2002
Responsible-Changed-Why:
    Looking at it.
State-Changed-From-To: open->analyzed
State-Changed-By: davem
State-Changed-When: Thu Sep 26 15:54:15 2002
State-Changed-Why:
    Well first of all, you shouldn't be using long double since
    those types are not done in hardware on any Sparc processor.
    All of this is being done with calls to software emulation
    libraries.
    
    The bug itself seems to be a bad hoist being done by the
    loop pass, this corrupts the flow information which is
    what causes the crash.

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=7335