🚀 go-pugleaf

Gcc 2.7.2 produces different assembly code for m68k-apple-netbsd target
depending on the host system for the compilation when compiling the file crt0.c
from NetBSD 1.1 (current).

When gcc 2.7.2 is run on the NetBSD/Mac68k host targeted for itself and
when it is running on a decstation
   ----------------
   # GCC was configured as follows:
   ./configure --target=m68k-apple-netbsd1.1
   echo host=mips-dec-ultrix4.4 target=m68k-apple-netbsd1.1 build=mips-dec-ultrix4.4
   -------------------
it produces seemingly correct output.

When gcc 2.7.2 is hosted on a Solaris 2.3 system and target'ed for the
NetBSD/Mac68k
   -----------------------------------------
   #!/bin/sh
   # GCC was configured as follows:
   ./configure --target=m68k-apple-netbsd1.1 --prefix=/home/gnu
   echo host=sparc-sun-solaris2.3 target=m68k-apple-netbsd1.1 build=sparc-sun-solaris2.3
   ----------------------------------------
it produces bad assembly code.

It seems that it tries to include some code for doing byte-swapping (is
the sparc and m68k of same endian-ness?) after L8:, but this code is
   * not needed, and it
   * causes assembly errors because a $-sign is used to denote an immediate
     value instead of a #-sign.
   * is wrong because it ends up swapping the two bytes in the word.

The rest of this message consists of

- a copy of the source file crt0.c
- a diff listing of the two following files
- a copy of the start of the assembly file generated on Ultrix (good)
- a copy of the start of the assembly file generated on Solaris (bad)

regards
Erik Bertelsen
UNI-C, The Danish Computing Centre for Research and Education.
================= source file =========================
/*	$NetBSD: crt0.c,v 1.14 1995/06/03 13:16:11 pk Exp $	*/
/*
 * Copyright (c) 1993 Paul Kranenburg
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Paul Kranenburg.
 * 4. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */


#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "%W% (Erasmus) %G%";
#endif /* LIBC_SCCS and not lint */

#include <sys/param.h>
#include <stdlib.h>

#include "common.h"

extern void	start __P((void)) asm("start");

void
start()
{
	struct kframe {
		int	kargc;
		char	*kargv[1];	/* size depends on kargc */
		char	kargstr[1];	/* size varies */
		char	kenvstr[1];	/* size varies */
	};
	/*
	 *	ALL REGISTER VARIABLES!!!
	 */
	register struct kframe *kfp;
	register char **argv, *ap;

#ifdef lint
	kfp = 0;
	initcode = initcode = 0;
#else /* not lint */
	asm("lea a6@(4),%0" : "=r" (kfp));	/* catch it quick */
#endif /* not lint */
	argv = &kfp->kargv[0];
	environ = argv + kfp->kargc + 1;

	if (ap = argv[0])
		if ((__progname = _strrchr(ap, '/')) == NULL)
			__progname = ap;
		else
			++__progname;

#ifdef DYNAMIC
	/* ld(1) convention: if DYNAMIC = 0 then statically linked */
#ifdef stupid_gcc
	if (&_DYNAMIC)
#else
	if ( ({volatile caddr_t x = (caddr_t)&_DYNAMIC; x; }) )
#endif
		__load_rtld(&_DYNAMIC);
#endif /* DYNAMIC */

asm("eprol:");

#ifdef MCRT0
	atexit(_mcleanup);
	monstartup((u_long)&eprol, (u_long)&etext);
#endif MCRT0

asm ("__callmain:");		/* Defined for the benefit of debuggers */
	exit(main(kfp->kargc, argv, environ));
}

#ifdef DYNAMIC
	asm("	___syscall:");
	asm("		movel	a7@+,a0");	/* return address */
	asm("		movel	a7@,d0");	/* syscall number */
	asm("		movel	a0,a7@");
	asm("		trap	#0");		/* do system call */
	asm("		bcc	1f");		/* check error */
	asm("		moveq	#-1,d0");
	asm("	1:	movel	a7@,a0");	/* get return address, leave */
	asm("		jmp	a0@");		/* correct amount on stack */

#endif /* DYNAMIC */

#include "common.c"

#ifdef MCRT0
asm ("	.text");
asm ("_eprol:");
#endif
============================diff listing between assembly outputs========
144c144,150
< 	cmpw #267,a6@(-30)
---
> 	movel a6@(-32),d0
> #APP
> 	rorw $8, d0
> 	rorl $16, d0
> 	rorw $8, d0
> #NO_APP
> 	cmpw #267,d0
=======================start of assembly file from Ultrix and from Macbsd===
#NO_APP
gcc2_compiled.:
___gnu_compiled_c:
.data
	.type	 _sccsid,@object
	.size	 _sccsid,18
_sccsid:
	.ascii "%W% (Erasmus) %G%\0"
.globl ___progname
	.even
	.type	 ___progname,@object
	.size	 ___progname,4
___progname:
	.long _empty
.text
	.even
.globl start
	.type	 start,@function
start:
	link a6,#-4
	moveml #0x2030,sp@-
#APP
	lea a6@(4),a3
#NO_APP
	lea a3@(4),a2
	movel a3@,d0
	lea a2@(4,d0:l:4),a0
	movel a0,_environ
	movel a2@,d2
	jeq L2
	pea 47:w
	movel d2,sp@-
	jbsr __strrchr
	movel d0,___progname
	addqw #8,sp
	jne L3
	movel d2,___progname
	jra L2
L3:
	addql #1,___progname
L2:
	movel #__DYNAMIC,a6@(-4)
	movel a6@(-4),d0
	movel a6@(-4),d0
	jeq L5
	pea __DYNAMIC
	jbsr ___load_rtld
	addqw #4,sp
L5:
#APP
	eprol:
	__callmain:
#NO_APP
	movel _environ,sp@-
	movel a2,sp@-
	movel a3@,sp@-
	jbsr _main
	movel d0,sp@-
	jbsr _exit
	nop
Lfe1:
	.size	 start,Lfe1-start
#APP
		___syscall:
			movel	a7@+,a0
			movel	a7@,d0
			movel	a0,a7@
			trap	#0
			bcc	1f
			moveq	#-1,d0
		1:	movel	a7@,a0
			jmp	a0@
#NO_APP
.lcomm _crt.4,36
LC0:
	.ascii "/usr/libexec/ld.so\0"
LC1:
	.ascii "No ld.so\12\0"
LC2:
	.ascii "Failure reading ld.so\12\0"
LC3:
	.ascii "Bad magic: ld.so\12\0"
LC4:
	.ascii "Cannot map ld.so\12\0"
LC5:
	.ascii "crt0: update /usr/libexec/ld.so\12\0"
LC6:
	.ascii "ld.so failed\12\0"
	.even
	.type	 ___load_rtld,@function
___load_rtld:
	link a6,#-32
	moveml #0x303c,sp@-
	movel a6@(8),a5
	movel #LC0,_crt.4+28
	clrl sp@-
	clrl sp@-
	pea LC0
	pea 5:w
	lea ___syscall,a2
	jbsr a2@
	lea _crt.4+8,a0
	movel d0,a0@
	addqw #8,sp
	addqw #8,sp
	moveq #-1,d2
	cmpl d0,d2
	jne L7
	pea 10:w
	pea LC1
	pea 2:w
	pea 4:w
	jbsr a2@
	pea 1:w
	pea 1:w
	jbsr a2@
	addw #24,sp
L7:
	pea 32:w
	pea a6@(-32)
	movel _crt.4+8,sp@-
	pea 3:w
	lea ___syscall,a2
	jbsr a2@
	addqw #8,sp
	addqw #8,sp
	moveq #31,d3
	cmpl d0,d3
	jcs L8
	pea 23:w
	pea LC2
	pea 2:w
	pea 4:w
	jbsr a2@
	pea 1:w
	pea 1:w
	jbsr a2@
	addw #24,sp
L8:
	movel a6@(-32),d0
	clrw d0
	tstl d0
	jeq L10
	cmpw #267,a6@(-30)
	jne L11
	jra L9
L10:
===========================assembly generated on solaris==================
#NO_APP
gcc2_compiled.:
___gnu_compiled_c:
.data
	.type	 _sccsid,@object
	.size	 _sccsid,18
_sccsid:
	.ascii "%W% (Erasmus) %G%\0"
.globl ___progname
	.even
	.type	 ___progname,@object
	.size	 ___progname,4
___progname:
	.long _empty
.text
	.even
.globl start
	.type	 start,@function
start:
	link a6,#-4
	moveml #0x2030,sp@-
#APP
	lea a6@(4),a3
#NO_APP
	lea a3@(4),a2
	movel a3@,d0
	lea a2@(4,d0:l:4),a0
	movel a0,_environ
	movel a2@,d2
	jeq L2
	pea 47:w
	movel d2,sp@-
	jbsr __strrchr
	movel d0,___progname
	addqw #8,sp
	jne L3
	movel d2,___progname
	jra L2
L3:
	addql #1,___progname
L2:
	movel #__DYNAMIC,a6@(-4)
	movel a6@(-4),d0
	movel a6@(-4),d0
	jeq L5
	pea __DYNAMIC
	jbsr ___load_rtld
	addqw #4,sp
L5:
#APP
	eprol:
	__callmain:
#NO_APP
	movel _environ,sp@-
	movel a2,sp@-
	movel a3@,sp@-
	jbsr _main
	movel d0,sp@-
	jbsr _exit
	nop
Lfe1:
	.size	 start,Lfe1-start
#APP
		___syscall:
			movel	a7@+,a0
			movel	a7@,d0
			movel	a0,a7@
			trap	#0
			bcc	1f
			moveq	#-1,d0
		1:	movel	a7@,a0
			jmp	a0@
#NO_APP
.lcomm _crt.4,36
LC0:
	.ascii "/usr/libexec/ld.so\0"
LC1:
	.ascii "No ld.so\12\0"
LC2:
	.ascii "Failure reading ld.so\12\0"
LC3:
	.ascii "Bad magic: ld.so\12\0"
LC4:
	.ascii "Cannot map ld.so\12\0"
LC5:
	.ascii "crt0: update /usr/libexec/ld.so\12\0"
LC6:
	.ascii "ld.so failed\12\0"
	.even
	.type	 ___load_rtld,@function
___load_rtld:
	link a6,#-32
	moveml #0x303c,sp@-
	movel a6@(8),a5
	movel #LC0,_crt.4+28
	clrl sp@-
	clrl sp@-
	pea LC0
	pea 5:w
	lea ___syscall,a2
	jbsr a2@
	lea _crt.4+8,a0
	movel d0,a0@
	addqw #8,sp
	addqw #8,sp
	moveq #-1,d2
	cmpl d0,d2
	jne L7
	pea 10:w
	pea LC1
	pea 2:w
	pea 4:w
	jbsr a2@
	pea 1:w
	pea 1:w
	jbsr a2@
	addw #24,sp
L7:
	pea 32:w
	pea a6@(-32)
	movel _crt.4+8,sp@-
	pea 3:w
	lea ___syscall,a2
	jbsr a2@
	addqw #8,sp
	addqw #8,sp
	moveq #31,d3
	cmpl d0,d3
	jcs L8
	pea 23:w
	pea LC2
	pea 2:w
	pea 4:w
	jbsr a2@
	pea 1:w
	pea 1:w
	jbsr a2@
	addw #24,sp
L8:
	movel a6@(-32),d0
	clrw d0
	tstl d0
	jeq L10
	movel a6@(-32),d0
#APP
	rorw $8, d0
	rorl $16, d0
	rorw $8, d0
#NO_APP
	cmpw #267,d0
	jne L11
	jra L9
L10:
=================end of attachments=================================