forked from mirror/qemu
You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
74 lines
2.2 KiB
C
74 lines
2.2 KiB
C
/*
|
|
* Test R5900-specific DIV1.
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include <inttypes.h>
|
|
#include <assert.h>
|
|
|
|
struct quotient_remainder { int32_t quotient, remainder; };
|
|
|
|
static struct quotient_remainder div1(int32_t rs, int32_t rt)
|
|
{
|
|
int32_t lo, hi;
|
|
|
|
__asm__ __volatile__ (
|
|
" div1 $0, %2, %3\n"
|
|
" mflo1 %0\n"
|
|
" mfhi1 %1\n"
|
|
: "=r" (lo), "=r" (hi)
|
|
: "r" (rs), "r" (rt));
|
|
|
|
assert(rs / rt == lo);
|
|
assert(rs % rt == hi);
|
|
|
|
return (struct quotient_remainder) { .quotient = lo, .remainder = hi };
|
|
}
|
|
|
|
static void verify_div1(int32_t rs, int32_t rt,
|
|
int32_t expected_quotient,
|
|
int32_t expected_remainder)
|
|
{
|
|
struct quotient_remainder qr = div1(rs, rt);
|
|
|
|
assert(qr.quotient == expected_quotient);
|
|
assert(qr.remainder == expected_remainder);
|
|
}
|
|
|
|
static void verify_div1_negations(int32_t rs, int32_t rt,
|
|
int32_t expected_quotient,
|
|
int32_t expected_remainder)
|
|
{
|
|
verify_div1(rs, rt, expected_quotient, expected_remainder);
|
|
verify_div1(rs, -rt, -expected_quotient, expected_remainder);
|
|
verify_div1(-rs, rt, -expected_quotient, -expected_remainder);
|
|
verify_div1(-rs, -rt, expected_quotient, -expected_remainder);
|
|
}
|
|
|
|
int main()
|
|
{
|
|
verify_div1_negations(0, 1, 0, 0);
|
|
verify_div1_negations(1, 1, 1, 0);
|
|
verify_div1_negations(1, 2, 0, 1);
|
|
verify_div1_negations(17, 19, 0, 17);
|
|
verify_div1_negations(19, 17, 1, 2);
|
|
verify_div1_negations(77773, 101, 770, 3);
|
|
|
|
verify_div1(-0x80000000, 1, -0x80000000, 0);
|
|
|
|
/*
|
|
* Supplementary explanation from the Toshiba TX System RISC TX79 Core
|
|
* Architecture manual, A-38 and B-7, https://wiki.qemu.org/File:C790.pdf
|
|
*
|
|
* Normally, when 0x80000000 (-2147483648) the signed minimum value is
|
|
* divided by 0xFFFFFFFF (-1), the operation will result in an overflow.
|
|
* However, in this instruction an overflow exception doesn't occur and
|
|
* the result will be as follows:
|
|
*
|
|
* Quotient is 0x80000000 (-2147483648), and remainder is 0x00000000 (0).
|
|
*/
|
|
verify_div1(-0x80000000, -1, -0x80000000, 0);
|
|
|
|
return 0;
|
|
}
|