[Bug optimization/14529] New: Reload decides to write into a fp constant, causing ICE

[jakub at gcc dot gnu dot org]

/* { dg-do compile } */
/* { dg-options "-O2" } */
/* { dg-options "-march=i686 -O2 -ffast-math -fPIC" { target i?86-*-* } } */

extern double foo (double x);
extern double bar (double x, double y);
extern double baz (double x) __attribute__ ((__const__));

int
test (double w, double x, double y, double z)
{
  double a[7], b, c;
  int i;

  b = x - w * w / 3;
  for (i = 0; i < 6; i++)
    a[i] = -w / 3;
  c = (y < 0 ? -1 : y > 0 ? 1 : 0) * bar (baz (y), 1.0 / 3) -
      (y < 0 ? -1 : y > 0 ? 1 : 0) * b / 3.0 * bar (baz (y), -1.0 / 3);
  if (!(y < 0.001 && y > -0.001))
    a[i] =
      foo (z / 3.0 +
           2 * 3.1415926535897932384626433832795 * (i % 3) / 3.0) * c - w / 3;
  return 3;
}

causes ICE on gcc-3_3-branch on i386 (works on gcc-3_2-branch, gcc-3_4-branch 
and
trunk).
Reload changes:
(insn:HI 119 46 49 2 (nil) (set (reg:DF 72)
        (reg:DF 87)) 93 {*movdf_nointeger} (nil)
    (expr_list:REG_EQUIV (mem/u/f:DF (plus:SI (reg:SI 3 ebx)
                (const:SI (unspec:SI [
                            (symbol_ref/u:SI ("*.LC0"))
                        ] 1))) [2 S8 A64])
        (nil)))
into buggy:
(insn:HI 119 46 49 2 (nil) (set (mem/u/f:DF (plus:SI (reg:SI 3 ebx)
                (const:SI (unspec:SI [
                            (symbol_ref/u:SI ("*.LC0"))
                        ] 1))) [2 S8 A64])
        (const_double:DF
3.33333333333333314829616256247390992939472198486328125e-1
[0x0.aaaaaaaaaaaaa8p-1])) 93 {*movdf_nointeger} (nil)
    (expr_list:REG_EQUIV (mem/u/f:DF (plus:SI (reg:SI 3 ebx)
                (const:SI (unspec:SI [
                            (symbol_ref/u:SI ("*.LC0"))
                        ] 1))) [2 S8 A64])
        (nil)))

-- 
           Summary: Reload decides to write into a fp constant, causing ICE
           Product: gcc
           Version: 3.3.4
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: jakub at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org
  GCC host triplet: x86_64-redhat-linux
GCC target triplet: i386-redhat-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14529