Commit 990aa328 authored by Fredrik Noring's avatar Fredrik Noring Committed by Aleksandar Markovic
Browse files

tests/tcg/mips: Add tests for R5900 DIV1 



Add a test for DIV1.

Reviewed-by: default avatarAleksandar Markovic <amarkovic@wavecomp.com>
Signed-off-by: default avatarFredrik Noring <noring@nocrew.org>
Signed-off-by: default avatarAleksandar Markovic <amarkovic@wavecomp.com>
parent 4d261a6a

tests/tcg/mips/mipsr5900/Makefile

+2 −1
Original line number Diff line number Diff line
@@ -8,7 +8,8 @@ SIM_FLAGS=-cpu R5900 
CC      = $(CROSS)gcc

CFLAGS  = -Wall -mabi=32 -march=r5900 -static



TESTCASES = mflohi1.tst

TESTCASES = div1.tst

TESTCASES += mflohi1.tst

TESTCASES += mtlohi1.tst

TESTCASES += mult.tst

TESTCASES += multu.tst

tests/tcg/mips/mipsr5900/div1.c

0 → 100644
+73 −0
Original line number Diff line number Diff line 
/*

 * 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;

}