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From: lance@ORC.OLIVETTI.COM
Newsgroups: gnu.gcc.bug
Subject: gcc1.36/i386 -> SysV as bug/feature
Message-ID: <8910041601.AA06959@Roma.ORC.Olivetti.Com>
Date: 4 Oct 89 08:01:19 GMT
Sender: daemon@tut.cis.ohio-state.edu
Distribution: gnu
Organization: GNUs Not Usenet
Lines: 48


gcc 1.36 puts out code that the AT&T SystemV.3.1 assembler chokes
on (it assembles with BSD/gas):

m380mach6{66} cat tst1.c

	struct from     { unsigned short field; } from[1];
	struct to       { char    field1; }to[1];
	
	lose()
	{
        	unsigned char i;
	
        	to[1].field1 = from[i].field;
	}

m380mach6{67} /lib/fgcc-cc1 -quiet -version -fvolatile tst1.c

	GNU C version 1.36 (80386, ATT syntax) compiled by GNU C version 1.36.
	default target switches: -m80387

m380mach6{68} /lib/fgcc-as tst1.s

	Assembler: tst1.c
        	aline 12        : syntax error

m380mach6{69} cat tst1.s

	        .file   "tst1.c"
	gcc_compiled.:
	.text
	        .align 4
	.globl lose
	lose:
	        pushl %ebp
        	movl %esp,%ebp
	        subl $4,%esp
        	movzbl -4(%ebp),%eax
	        movw from(,%eax,2),%ax
	        movb %ax,to+1		<-- chunder!
	.L1:
	        leave
        	ret
	.comm to,1
	.comm from,2

lance
lance@orc.olivetti.com