Re: Modifying ARM code generator for elimination of 8bit writes - need help

[Wolfgang Mües <wolfgang at iksw-muees dot de>]

Rask,

On Thursday 08 June 2006 20:12, Rask Ingemann Lambertsen wrote:

> Also, undo the change to arm_legitimate_address_p() arm.c.

Hmmm....

> arm-elf-gcc -g -mswp-byte-writes -Wall -O2 -fomit-frame-pointer
> -ffast-math -mthumb-interwork -isystem
> /usr/lib/devkitpro/libnds/include -mcpu=arm9tdmi -mtune=arm9tdmi
> -DARM9 -S arm9_main.c -o arm9_main.S arm9_main.c: In function 'test':
> arm9_main.c:20: error: unable to generate reloads for:
> (insn:HI 20 21 22 1 arm9_main.c:16 (set (mem/v:QI (post_inc:SI
> (reg/v/f:SI 3 r3 [orig:102 p ] [102])) [0 S1 A8]) (subreg/s/u:QI
> (reg:SI 2 r2 [orig:103 c.36 ] [103]) 0)) 157 {*arm_movqi_insn_swp}
> (nil) (expr_list:REG_INC (reg/v/f:SI 3 r3 [orig:102 p ] [102])
> (nil)))
> arm9_main.c:20: internal compiler error: in find_reloads, at
> reload.c:3720

void test(void)
{
	static unsigned char c = 20;
	volatile unsigned char * p;
	int i;

	p = (volatile unsigned char *) 0x08000000;
	for (i = 0; i < 1000; i++)
		*p++ = c;

	c = 40;
	c = c;
}

Without the change in arm_legitimate_address_p, we get post increment 
pointer into swpb. The non-working 'Q' constraint....

regards
Wolfgang
-- 
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and wrote their own device drivers.

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