[craign@cheque.uq.edu.au: ARM GCC Bug]

[Nick Clifton <nickc at cygnus dot com>]

Forwarded bug report:

------- Start of forwarded message -------
Date: Wed, 19 Jan 2000 19:11:46 -0500 (EST)
From: "Craig Newell (W2/VK4YEQ)" <craign@cheque.uq.edu.au>
To: nickc@cygnus.com
Subject: ARM GCC Bug


Hi There,

  I have been given your name by James Smith as someone I could report GCC
problems to wrt. the ARM port.  If I am talking to the wrong person,
please say so (and forward this bug) on to the correct person.

  Anyway, the bug report including code to reproduce it is below: 

	Thanks,

		CraigN
- ---
      Craig Newell                email: CraigN@cheque.uq.edu.au
      Free Spirit                 icbm:  somewhere in NJ, USA

- -----------------------------------------------------------------------------

GCC Configuration:
	source:			EGCS CVS tree (19:00 EST Jan 19, 2000)
	compiler target:	arm-elf
	compiler host:		linux i386 (RedHat 6.1 plus all updates)
	compiler options:	arm-elf-gcc -O2 -S bug.c

Bug: 
  
  The bug is that the loop counter "c" gets decremented by 2 each loop
instead of by one.

- --- bug.c -------------------------------------
int a(int c, char **v) {
	while (c--) {
		if (!strcmp(*v,"a"))  {
			c--;
			continue;
		}
		if (!strcmp(*v++,"b"))
			return 0;
	}
	return 1;
}
- --- bug.S C------------------------------------
@ Generated by gcc 2.96 20000119 (experimental) for ARM/elf
	.file	"t.c"
 .gcc2_compiled.:
	.section .rodata
	.align	2
.LC0:
	.ascii	"a\000"
	.align	2
.LC1:
	.ascii	"b\000"
.text
	.align	2
	.global	a
	.type	 a,function
a:
	@ args = 0, pretend = 0, frame = 0
	@ frame_needed = 1, current_function_anonymous_args = 0
	mov	ip, sp
	stmfd	sp!, {r4, r5, fp, ip, lr, pc}
	sub	r4, r0, #1
	cmn	r4, #1
	sub	fp, ip, #4
	mov	r5, r1
	beq	.L4
.L5:
	ldr	r1, .L9
	sub	r4, r4, #2
	ldr	r0, [r5, #0]
	bl	strcmp
	cmp	r0, #0
	ldr	r1, .L9+4
	beq	.L3
	ldr	r0, [r5], #4
	bl	strcmp
	cmp	r0, #0
	ldmeqea	fp, {r4, r5, fp, sp, pc}
.L3:
	cmn	r4, #1
	bne	.L5
.L4:
	mov	r0, #1
	ldmea	fp, {r4, r5, fp, sp, pc}
.L10:
	.align	2
.L9:
	.word	.LC0
	.word	.LC1
.Lfe1:
	.size	 a,.Lfe1-a
- --------------------------------------
------- End of forwarded message -------