more_x87_fp.c

The Valgrind distribution has multiple tools. The most popular is the memory checking tool (called M

/* On amd64, to exercise x87, compile with 
    gcc4 -ffast-math -mfpmath=387 -mfancy-math-387

  gcc4 really does generate all the sin cos tan stuff as 
  x87 insns inline.  gcc 3.3 doesn't, which makes the test
  pretty useless, but it should still pass.  To be on the safe
  side we need to link with -lm to handle the gcc 3.3 behaviour.
*/

/* Derived from: */

/*
 *  x86 CPU test
 *
 *  Copyright (c) 2003 Fabrice Bellard
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */


#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <inttypes.h>
#include <math.h>

/**********************************************/

void test_fops(double a, double b)
{
    printf("a=%f b=%f a+b=%f\n", a, b, a + b);
    printf("a=%f b=%f a-b=%f\n", a, b, a - b);
    printf("a=%f b=%f a*b=%f\n", a, b, a * b);
    printf("a=%f b=%f a/b=%f\n", a, b, a / b);
    // requires fprem/fprem1 -- not done
    //printf("a=%f b=%f fmod(a, b)=%f\n", a, b, fmod(a, b));
    printf("a=%f sqrt(a)=%f\n", a, sqrt(a));
    printf("a=%f sin(a)=%f\n", a, sin(a));
    printf("a=%f cos(a)=%f\n", a, cos(a));
    printf("a=%f tan(a)=%f\n", a, tan(a));
    printf("a=%f log(a)=%f\n", a, log(a));
    printf("a=%f exp(a)=%f\n", a, exp(a));
    printf("a=%f b=%f atan2(a, b)=%f\n", a, b, atan2(a, b));
    /* just to test some op combining */
    printf("a=%f asin(sin(a))=%f\n", a, asin(sin(a)));
    printf("a=%f acos(cos(a))=%f\n", a, acos(cos(a)));
    printf("a=%f atan(tan(a))=%f\n", a, atan(tan(a)));
}
#define CC_C    0x0001
#define CC_P    0x0004
#define CC_A    0x0010
#define CC_Z    0x0040
#define CC_S    0x0080
#define CC_O    0x0800


void test_fcmp(double a, double b)
{
    printf("(%f<%f)=%d\n",
           a, b, a < b);
    printf("(%f<=%f)=%d\n",
           a, b, a <= b);
    printf("(%f==%f)=%d\n",
           a, b, a == b);
    printf("(%f>%f)=%d\n",
           a, b, a > b);
    printf("(%f<=%f)=%d\n",
           a, b, a >= b);
    {
        unsigned long long int eflags;
        /* test f(u)comi instruction */
        asm("fcomi %2, %1\n"
            "pushfq\n"
            "popq %0\n"
            : "=r" (eflags)
            : "t" (a), "u" (b));
        printf("fcomi(%f %f)=%08llx\n", a, b, eflags & (CC_Z | CC_P | CC_C));
    }
}

void test_fcvt(double a)
{
    float fa;
    long double la;
    int16_t fpuc;
    int i;
    int64_t lla;
    int ia;
    int16_t wa;
    double ra;

    fa = a;
    la = a;
    printf("(float)%e = %e\n", a, fa);
    printf("(long double)%f = %Lf\n", a, la);
    printf("a=%016Lx\n", *(long long *)&a);
    printf("la=%016Lx %04x\n", *(long long *)&la, 
           *(unsigned short *)((char *)(&la) + 8));

    /* test all roundings */
    asm volatile ("fstcw %0" : "=m" (fpuc));
    for(i=0;i<4;i++) {
      int16_t tmp = (fpuc & ~0x0c00) | (i << 10);
        asm volatile ("fldcw %0" : : "m" (tmp));
        wa=0;//asm volatile ("fist %0" : "=m" (wa) : "t" (a));
	asm volatile ("fistl %0" : "=m" (ia) : "t" (a));
        asm volatile ("fistpll %0" : "=m" (lla) : "t" (a) : "st");
        asm volatile ("frndint ; fstl %0" : "=m" (ra) : "t" (a));
        asm volatile ("fldcw %0" : : "m" (fpuc));
        printf("(short)a = %d\n", wa);
        printf("(int)a = %d\n", ia);
        printf("(int64_t)a = %lld\n", (long long int)lla);
        printf("rint(a) = %f\n", ra);
    }
}

#define TEST(N) \
    asm("fld" #N : "=t" (a)); \
    printf("fld" #N "= %f\n", a);

void test_fconst(void)
{
    double a;
    TEST(1);
    TEST(l2t);
    TEST(l2e);
    TEST(pi);
    TEST(lg2);
    TEST(ln2);
    TEST(z);
}

void test_fbcd(double a)
{
    unsigned short bcd[5];
    double b;

    asm("fbstp %0" : "=m" (bcd[0]) : "t" (a) : "st");
    asm("fbld %1" : "=t" (b) : "m" (bcd[0]));
    printf("a=%f bcd=%04x%04x%04x%04x%04x b=%f\n", 
           a, bcd[4], bcd[3], bcd[2], bcd[1], bcd[0], b);
}

#define TEST_ENV(env, save, restore)\
{\
    memset((env), 0xaa, sizeof(*(env)));\
    for(i=0;i<5;i++)\
        asm volatile ("fldl %0" : : "m" (dtab[i]));\
    asm(save " %0\n" : : "m" (*(env)));\
    asm(restore " %0\n": : "m" (*(env)));\
    for(i=0;i<5;i++)\
        asm volatile ("fstpl %0" : "=m" (rtab[i]));\
    for(i=0;i<5;i++)\
        printf("res[%d]=%f\n", i, rtab[i]);\
    printf("fpuc=%04x fpus=%04x fptag=%04x\n",\
           (env)->fpuc,\
           (env)->fpus & 0xff00,\
           (env)->fptag);\
}

void test_fenv(void)
{
    struct __attribute__((packed)) {
        uint16_t fpuc;
        uint16_t dummy1;
        uint16_t fpus;
        uint16_t dummy2;
        uint16_t fptag;
        uint16_t dummy3;
        uint32_t ignored[4];
        long double fpregs[8];
    } float_env32;
    struct __attribute__((packed)) {
        uint16_t fpuc;
        uint16_t fpus;
        uint16_t fptag;
        uint16_t ignored[4];
        long double fpregs[8];
    } float_env16;
    double dtab[8];
    double rtab[8];
    int i;

    for(i=0;i<8;i++)
        dtab[i] = i + 1;

    TEST_ENV(&float_env16, "data16 fnstenv", "data16 fldenv");
    TEST_ENV(&float_env16, "data16 fnsave", "data16 frstor");
    TEST_ENV(&float_env32, "fnstenv", "fldenv");
    TEST_ENV(&float_env32, "fnsave", "frstor");

    /* test for ffree */
    for(i=0;i<5;i++)
        asm volatile ("fldl %0" : : "m" (dtab[i]));
    asm volatile("ffree %st(2)");
    asm volatile ("fnstenv %0\n" : : "m" (float_env32));
    asm volatile ("fninit");
    printf("fptag=%04x\n", float_env32.fptag);
}


#define TEST_FCMOV(a, b, eflags, CC)\
{\
    double res;\
    asm("pushq %3\n"\
        "popfq\n"\
        "fcmov" CC " %2, %0\n"\
        : "=t" (res)\
        : "0" (a), "u" (b), "g" ((long long int)eflags));\
    printf("fcmov%s eflags=0x%04llx-> %f\n", \
           CC, (long long int)eflags, res);\
}

void test_fcmov(void)
{
    double a, b;
    long long int eflags, i;

    a = 1.0;
    b = 2.0;
    for(i = 0; i < 4; i++) {
        eflags = 0;
        if (i & 1)
            eflags |= CC_C;
        if (i & 2)
            eflags |= CC_Z;
        TEST_FCMOV(a, b, eflags, "b");
        TEST_FCMOV(a, b, eflags, "e");
        TEST_FCMOV(a, b, eflags, "be");
        TEST_FCMOV(a, b, eflags, "nb");
        TEST_FCMOV(a, b, eflags, "ne");
        TEST_FCMOV(a, b, eflags, "nbe");
    }
    TEST_FCMOV(a, b, 0, "u");
    TEST_FCMOV(a, b, CC_P, "u");
    TEST_FCMOV(a, b, 0, "nu");
    TEST_FCMOV(a, b, CC_P, "nu");
}

void test_floats(void)
{
    test_fops(2, 3);
    test_fops(1.4, -5);
    test_fcmp(2, -1);
    test_fcmp(2, 2);
    test_fcmp(2, 3);
    test_fcvt(0.5);
    test_fcvt(-0.5);
    test_fcvt(1.0/7.0);
    test_fcvt(-1.0/9.0);
    test_fcvt(32768);
    test_fcvt(-1e20);
    test_fconst();
}

int main ( void )
{
  test_floats();
  return 0;
}