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From: olson%modular.UUCP@ARIZONA.EDU (Jon Olson)
Newsgroups: gnu.gcc.bug
Subject: (none)
Message-ID: <8903230545.AA21429@>
Date: 23 Mar 89 05:45:12 GMT
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Distribution: gnu
Organization: GNUs Not Usenet
Lines: 100

To whom it may concern,

Here's a bit of code that causes a segment violation in GCC V1.33 on
a Sun-3 running SunOS 4.0.  Seems that GCC is generating a SUBREG(MEM).
The routine `equiv_constant' in cse.c expects only SUBREG(REG) and
causes a segment violation when given SUBREG of anything else.
Although I'm not sure if GCC should even generate a SUBREG(MEM),
I put in the following quicky patch in cse.c so that this would not
generate a segment violation.

*** cse.c.save  Wed Feb 22 09:10:28 1989
--- cse.c       Wed Feb 22 09:08:09 1989
***************
*** 2391,2397 ****
      return tem1;
    /* If integer truncation is being done with SUBREG,
       we can compute the result.  */
!   else if (GET_CODE (x) == SUBREG && && SUBREG_WORD (x) == 0
           && (tem1 = qty_const[reg_qty[REGNO (SUBREG_REG (x))]]) != 0
           /* Make sure it is a known integer.  */
           && GET_CODE (tem1) == CONST_INT
--- 2391,2398 ----
      return tem1;
    /* If integer truncation is being done with SUBREG,
       we can compute the result.  */
!   else if (GET_CODE (x) == SUBREG && GET_CODE (SUBREG_REG(x)) == REG
!          && SUBREG_WORD (x) == 0
           && (tem1 = qty_const[reg_qty[REGNO (SUBREG_REG (x))]]) != 0
           /* Make sure it is a known integer.  */
           && GET_CODE (tem1) == CONST_INT

---------------------Sample code which generates SEGV----------------------
#define X$CHAR  1
#define X$WORD  2
#define X$INT   3
#define X$FLOAT 4
#define X$UNSIGNED 8

union ANY
  {
  char *c;
  unsigned char *uc;
  short *s;
  unsigned short *us;
  int *i;
  unsigned int *ui;
  float *f;
  };

static convertfield( pto, pfrom, new_type, old_type, machine )
union ANY pto, pfrom;
unsigned short new_type, old_type;
int machine;
  {
  union { char c; short s; int i; float f; } u;
  unsigned char isint = 1;

#ifndef vms
  if( machine )
    {
    switch( old_type & 0xFF )
      {
      case X$CHAR:  u.c = *pfrom.c; pfrom.c = &u.c; break;
      case X$WORD:  u.s = *pfrom.s; vaxshort( pfrom.s = &u.s ); break;
      case X$INT:   u.i = *pfrom.i; vaxint(   pfrom.i = &u.i ); break;
      case X$FLOAT: u.f = *pfrom.f; vaxfloat( pfrom.f = &u.f ); break;
      }
    }
#endif
  switch( old_type & 0xFF )
    {
  case X$CHAR:  u.i = old_type & X$UNSIGNED ? *pfrom.uc : *pfrom.c;
	        break;
  case X$WORD:  u.i = old_type & X$UNSIGNED ? *pfrom.us : *pfrom.s;
	        break;
  case X$INT:   u.i = *pfrom.i;
		break;
  case X$FLOAT: u.f = *pfrom.f;
		isint = 0;
		break;
    }
  switch( new_type & 0XFF )
    {
  case X$CHAR:  *pto.c = isint ? u.i : (int)u.f;
		break;
  case X$WORD:  *pto.s = isint ? u.i : (int)u.f;
		break;
  case X$INT:   *pto.i = isint ? u.i : (int)u.f;
		break;
  case X$FLOAT: *pto.f = isint ? (float)u.i : u.f;
		break;
    }
  }
----------------------------------------------------------------
Jon Olson, Modular Mining Systems
	   1210 E. Pennsylvania St.
	   Tucson, AZ 85714

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