[Bug optimization/10392] [3.3/3.4 regression] [SH] optimizer generates faulty array indexing

["joern dot rennecke at superh dot com" <gcc-bugzilla at gcc dot gnu dot org>]

------- Additional Comments From joern dot rennecke at superh dot com  2004-01-14 19:03 -------
Subject: Re:  [3.3/3.4 regression] [SH] optimizer generates faulty array indexing

> ------- Additional Comments From gdr at gcc dot gnu dot org  2003-12-21 18:45 -------
> Joern --
> 
> This bug is present on both 3.3.x branch and mainline.
> It has "Severity:" set to critical.  Do you think we should
> keep it open for 3.3.3? (There is virtually no chance I fix 
> this myself as I don't speak SH).

AFAICS the problem is no longer present in mainline; I've attached the output
I get with yesterday's compiler.  When did you last reconfirm the bug?

The incorrect use of reload registers observed is consistent with
a problem in reg_overlap_mentioned_for_reload_p that I've fixed with
this patch:

2003-12-15  J"orn Rennecke <joern.rennecke@superh.com>

        * reload.c (reg_overlap_mentioned_for_reload_p):
        When looking at a PLUS in X, avoid spuriously returning nonzero
        when IN is a REG or another simple PLUS, or a MEM containing one.

http://gcc.gnu.org/ml/gcc-patches/2003-09/msg01299.html

	.file	"10392.c"
	.text
	.section	.rodata.str1.4,"aMS",@progbits,1
	.align 2
.LC0:
	.string	"one"
	.align 2
.LC1:
	.string	"two"
	.text
	.align 1
	.align 5
	.global	_func
	.type	_func, @function
_func:
	mov.l	r8,@-r15
	mov.l	r9,@-r15
	mov.l	r10,@-r15
	mov	#0,r10
	mov.l	r11,@-r15
	mov	r5,r11
	mov.l	r12,@-r15
	mov	r4,r12
	mov.l	r13,@-r15
	mov	#1,r13
	mov.l	r14,@-r15
	sts.l	pr,@-r15
	mov.w	.L13,r0
	add	#-68,r15
	mov.l	.L10,r1
	add	#-68,r15
	mov	r15,r14
	add	r14,r0
	mov.l	r1,@r0
	mov.l	.L11,r9
	mov.l	.L12,r1
	mov.l	r1,@(4,r0)
.L5:
	mov.w	.L13,r1
	mov	r10,r2
	shll2	r2
	mov	r14,r0
	add	r2,r1
	jsr	@r9
	mov.l	@(r0,r1),r4
	jsr	@r9
	mov	r14,r4
	mov	r12,r4
	jsr	@r9
	mov	r0,r8
	jsr	@r9
	mov	r11,r4
	jsr	@r9
	mov	r8,r4
	mov	r10,r1
	add	#1,r1
	extu.b	r1,r10
	cmp/hi	r13,r10
	bf	.L5
	add	#68,r14
	add	#68,r14
	mov	r14,r15
	lds.l	@r15+,pr
	mov.l	@r15+,r14
	mov.l	@r15+,r13
	mov.l	@r15+,r12
	mov.l	@r15+,r11
	mov.l	@r15+,r10
	mov.l	@r15+,r9
	rts	
	mov.l	@r15+,r8
	.align 1
.L13:
	.short	128
.L14:
	.align 2
.L10:
	.long	.LC0
.L11:
	.long	_use
.L12:
	.long	.LC1
	.size	_func, .-_func
	.ident	"GCC: (GNU) 3.4.0 20040113 (experimental)"


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=10392