[RFC/PATCH 0/3] ARM: Use udiv/sdiv for __aeabi_{u}idiv library functions

Nicolas Pitre nicolas.pitre at linaro.org
Sun Nov 22 18:36:45 PST 2015


On Sun, 22 Nov 2015, Arnd Bergmann wrote:

> I've also found some /proc/cpuinfo output to cross-reference SoCs
> to their core names.
> 
> 		variant	part	revision	name		features
> dove:		0	0x581	5		PJ4		idivt

I just managed to boot my dusty Dove DB and ran a quick test programon 
it. Its cpuinfo corresponds to the above.

$ cat m.c
#include <stdio.h>
int mydiv(int, int);
int main()
{
        printf("div test\n");
        printf("%d\n", mydiv(12345678, 37));
        return 0;
}
$ cat d.c
int mydiv(int x, int y)
{
        return x/y;
}
$ gcc -o test m.c d.c
$ ./test
div test
333666
$ gcc -o test m.c d.c -march=armv7ve -mthumb
$ ./test
div test
333666
$ gcc -o test m.c d.c -march=armv7ve -marm
$ ./test
div test
Illegal instruction (core dumped)
$


Nicolas



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