[Bug c/31385] New: gcc fails to find spill register for decimal arithmetic

[Bug c/31385] New: gcc fails to find spill register for decimal arithmetic

[beebe at math dot utah dot edu]

In compilation of a large library of code for decimal floating-point
arithmetic, I found that compilations with -g would succeed, but most
would fail with -O1, -O2, or -O3 on IA-32.  I've taken a single example
and chopped away extraneous code to produce a standalone file
that exhibits the compiler error:

% cat bug002.c
typedef _Decimal32 fp_t;

extern fp_t g(fp_t);

fp_t
bug(fp_t x)
{
    fp_t result;
    int n;
    fp_t f, f3, y, z;

    n = 0;
    y = 1.DF;
    f = g(x);

    if (f < 0.DF)
        f = -f;

    f3 = 2.DF;

    z = (y + y + f / (y * y));
    y = (z + z) / (9.DF) + f3 / (z * z);

    result = y;

    return (result);
}

% gcc --version
gcc (GCC) 4.3.0 20070316 (experimental)

% gcc -c -O1 bug002.c
bug002.c: In function 'bug':
bug002.c:27: error: unable to find a register to spill in class 'GENERAL_REGS'
bug002.c:27: error: this is the insn:
(insn 25 24 26 3 (set (subreg:SI (reg/v:SD 59 [ f ]) 0)
        (plus:SI (subreg:SI (reg/v:SD 59 [ f ]) 0)
            (const_int -2147483648 [0x80000000]))) 144 {*lea_1} (nil)
    (nil))
bug002.c:27: internal compiler error: in spill_failure, at reload1.c:1944


-- 
           Summary: gcc fails to find spill register for decimal arithmetic
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: beebe at math dot utah dot edu
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31385

[Bug target/31385] gcc fails to find spill register for decimal arithmetic

[janis at gcc dot gnu dot org]

------- Comment #1 from janis at gcc dot gnu dot org  2007-08-17 18:21 -------
Current mainline (revision 127590) still gets this ICE for i686-pc-linux-gnu
with either bid or dpd decimal float support.  The current line number for the
ICE is reload1.c:2001.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31385

[Bug target/31385] gcc fails to find spill register for decimal arithmetic

[hjl at lucon dot org]

------- Comment #2 from hjl at lucon dot org  2007-08-18 16:47 -------
A patch is posted at

http://gcc.gnu.org/ml/gcc-patches/2007-08/msg01183.html


-- 

hjl at lucon dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                URL|                            |http://gcc.gnu.org/ml/gcc-
                   |                            |patches/2007-
                   |                            |08/msg01183.html
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2007-08-18 16:47:37
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31385

[Bug target/31385] gcc fails to find spill register for decimal arithmetic

[hjl at gcc dot gnu dot org]

------- Comment #3 from hjl at gcc dot gnu dot org  2007-08-27 14:14 -------
Subject: Bug 31385

Author: hjl
Date: Mon Aug 27 14:14:31 2007
New Revision: 127833

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=127833
Log:
gcc/

2007-08-27  H.J. Lu  <hongjiu.lu@intel.com>

        PR target/31385
        * config/i386/i386.h (VALID_DFP_MODE_P): New.
        * config/i386/i386.c (ix86_hard_regno_mode_ok): Allow DFP in
        GPR.

gcc/testsuite/

2007-08-27  H.J. Lu  <hongjiu.lu@intel.com>

        PR target/31385
        * gcc.dg/dfp/pr31385.c: New.

Added:
    trunk/gcc/testsuite/gcc.dg/dfp/pr31385.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/config/i386/i386.c
    trunk/gcc/config/i386/i386.h
    trunk/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31385

[Bug target/31385] gcc fails to find spill register for decimal arithmetic

[hjl at lucon dot org]

------- Comment #4 from hjl at lucon dot org  2007-08-27 14:17 -------
Fixed by

http://gcc.gnu.org/ml/gcc-patches/2007-08/msg01809.html


-- 

hjl at lucon dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31385