From mboxrd@z Thu Jan  1 00:00:00 1970
From: hjl@lucon.org (H.J. Lu)
To: wilson@cygnus.com, law@cygnus.com, scox@cygnus.com, crux@pool.informatik.rwth-aachen.de
Cc: egcs@cygnus.com
Subject: More fp bug in egcs
Date: Sat, 25 Apr 1998 18:25:00 -0000
Message-id: <m0yTGCP-00059AC@ocean.lucon.org>
X-SW-Source: 1998-04/msg01026.html

Hi,

I discovered this x86 fp bug by accident.

# gcc -B/home/work/gnu/bin/egcs/gcc/ -S  mpgeomnn.c
gcc: Internal compiler error: program cc1 got fatal signal 6

It is very similar to the one fixed by Jim. It will compile if -O is
used. I think it may have something to do with Jim's patch. In the
greg rtl dump, the clobbered register is used as input in the next
insn.

Thanks.


-- 
H.J. Lu (hjl@gnu.org)
---mpgeomnn.c---
typedef struct _geom_elem {
  double        coeffs[6];
  double        constant[3 ];
  int		do_band[3];
} pGeomDefRec, *pGeomDefPtr;
typedef struct _mpgeombanddef {
	double	first_mlow,	 
		first_mhigh;	 
	int	first_ilow,	 
		first_ihigh;	 
	double	*s_locs;	 
	int	*x_locs;	 
	int	x_start;
	int	x_end;
	int	int_constant;	 
	int	yOut;		 
	int	out_width;	 
	int	out_height;	 
	int	in_width;	 
	int	in_height;
	int	lo_src_available;  
	int	hi_src_available;
	void	(*linefunc) ();
	void	(*fillfunc) ();
} mpGeometryBandRec, *mpGeometryBandPtr;
typedef void *pointer;
typedef unsigned char  CARD8;
typedef CARD8 BytePixel;
static void  BiGL_B  (OUTP,srcimg,width,sline,pedpvt,pvtband)	pointer OUTP;	pointer *srcimg;	register int width;	int sline;	pGeomDefPtr pedpvt; mpGeometryBandPtr pvtband;	{	register float s, t, st;	register double a  = pedpvt->coeffs[0];	register double c  = pedpvt->coeffs[2];	register double srcpix  = a * ((double)(0.0000))  +	pedpvt->coeffs[1] * (pvtband->yOut + ((double)(0.0000)) ) +	pedpvt->coeffs[4];	register double srcline = c * ((double)(0.0000))  +	pedpvt->coeffs[3] * (pvtband->yOut + ((double)(0.0000)) ) +	pedpvt->coeffs[5];	register int 	isrcline,isrcpix;	register   BytePixel  constant = (  BytePixel ) pvtband->  int_constant ;	register   BytePixel  *outp	= (  BytePixel  *) OUTP;	register   BytePixel  *ptrIn, *ptrJn;	register   BytePixel  val;	register int 	srcwidth = pvtband->in_width - 1;	register int 	minline  = pvtband->lo_src_available;	register int 	maxline  = pvtband->hi_src_available;	while ( width > 0 ) { isrcline = srcline; isrcpix  = srcpix; val = constant; if ( (isrcline >= minline) && (isrcline < maxline) ) {	s = srcpix - isrcpix;	ptrIn = (  BytePixel  *) srcimg[isrcline]; t = srcline - isrcline;	ptrJn = (  BytePixel  *) srcimg[isrcline+1]; st = s * t;	if ( (isrcpix >= 0) && (isrcpix < srcwidth) )	val =	ptrIn[isrcpix]   * ((float)1. - s - t + st) + ptrIn[isrcpix+1] * (s - st) +	ptrJn[isrcpix]   * (t - st) +	ptrJn[isrcpix+1] * (st) +   (float)0.5 ;	}	width--; srcline += c; srcpix  += a; *outp++ = val; }	}