diff options
Diffstat (limited to 'qemu/tests/tcg/test-i386-fprem.c')
| -rw-r--r-- | qemu/tests/tcg/test-i386-fprem.c | 353 |
1 files changed, 353 insertions, 0 deletions
diff --git a/qemu/tests/tcg/test-i386-fprem.c b/qemu/tests/tcg/test-i386-fprem.c new file mode 100644 index 000000000..e91fb1ae9 --- /dev/null +++ b/qemu/tests/tcg/test-i386-fprem.c @@ -0,0 +1,353 @@ +/* + * x86 FPREM test - executes the FPREM and FPREM1 instructions with corner case + * operands and prints the operands, result and FPU status word. + * + * Run this on real hardware, then under QEMU, and diff the outputs, to compare + * QEMU's implementation to your hardware. The 'run-test-i386-fprem' make + * target does this. + * + * Copyright (c) 2003 Fabrice Bellard + * Copyright (c) 2012 Catalin Patulea + * + * 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, see <http://www.gnu.org/licenses/>. + */ +#include "qemu/compiler.h" +#include "qemu/osdep.h" +#include <stdio.h> +#include <inttypes.h> + +/* + * Inspired by <ieee754.h>'s union ieee854_long_double, but with single + * long long mantissa fields and assuming little-endianness for simplicity. + */ +union float80u { + long double d; + + /* This is the IEEE 854 double-extended-precision format. */ + struct { + unsigned long long mantissa:63; + unsigned int one:1; + unsigned int exponent:15; + unsigned int negative:1; + unsigned int empty:16; + } QEMU_PACKED ieee; + + /* This is for NaNs in the IEEE 854 double-extended-precision format. */ + struct { + unsigned long long mantissa:62; + unsigned int quiet_nan:1; + unsigned int one:1; + unsigned int exponent:15; + unsigned int negative:1; + unsigned int empty:16; + } QEMU_PACKED ieee_nan; +}; + +#define IEEE854_LONG_DOUBLE_BIAS 0x3fff + +static const union float80u q_nan = { + .ieee_nan.negative = 0, /* X */ + .ieee_nan.exponent = 0x7fff, + .ieee_nan.one = 1, + .ieee_nan.quiet_nan = 1, + .ieee_nan.mantissa = 0, +}; + +static const union float80u s_nan = { + .ieee_nan.negative = 0, /* X */ + .ieee_nan.exponent = 0x7fff, + .ieee_nan.one = 1, + .ieee_nan.quiet_nan = 0, + .ieee_nan.mantissa = 1, /* nonzero */ +}; + +static const union float80u pos_inf = { + .ieee.negative = 0, + .ieee.exponent = 0x7fff, + .ieee.one = 1, + .ieee.mantissa = 0, +}; + +static const union float80u pseudo_pos_inf = { /* "unsupported" */ + .ieee.negative = 0, + .ieee.exponent = 0x7fff, + .ieee.one = 0, + .ieee.mantissa = 0, +}; + +static const union float80u pos_denorm = { + .ieee.negative = 0, + .ieee.exponent = 0, + .ieee.one = 0, + .ieee.mantissa = 1, +}; + +static const union float80u smallest_positive_norm = { + .ieee.negative = 0, + .ieee.exponent = 1, + .ieee.one = 1, + .ieee.mantissa = 0, +}; + +static void fninit() +{ + asm volatile ("fninit\n"); +} + +static long double fprem(long double a, long double b, uint16_t *sw) +{ + long double result; + asm volatile ("fprem\n" + "fnstsw %1\n" + : "=t" (result), "=m" (*sw) + : "0" (a), "u" (b) + : "st(1)"); + return result; +} + +static long double fprem1(long double a, long double b, uint16_t *sw) +{ + long double result; + asm volatile ("fprem1\n" + "fnstsw %1\n" + : "=t" (result), "=m" (*sw) + : "0" (a), "u" (b) + : "st(1)"); + return result; +} + +#define FPUS_IE (1 << 0) +#define FPUS_DE (1 << 1) +#define FPUS_ZE (1 << 2) +#define FPUS_OE (1 << 3) +#define FPUS_UE (1 << 4) +#define FPUS_PE (1 << 5) +#define FPUS_SF (1 << 6) +#define FPUS_SE (1 << 7) +#define FPUS_C0 (1 << 8) +#define FPUS_C1 (1 << 9) +#define FPUS_C2 (1 << 10) +#define FPUS_TOP 0x3800 +#define FPUS_C3 (1 << 14) +#define FPUS_B (1 << 15) + +#define FPUS_EMASK 0x007f + +#define FPUC_EM 0x3f + +static void psw(uint16_t sw) +{ + printf("SW: C3 TopC2C1C0\n"); + printf("SW: %c %d %3d %d %d %d %c %c %c %c %c %c %c %c\n", + sw & FPUS_B ? 'B' : 'b', + !!(sw & FPUS_C3), + (sw & FPUS_TOP) >> 11, + !!(sw & FPUS_C2), + !!(sw & FPUS_C1), + !!(sw & FPUS_C0), + (sw & FPUS_SE) ? 'S' : 's', + (sw & FPUS_SF) ? 'F' : 'f', + (sw & FPUS_PE) ? 'P' : 'p', + (sw & FPUS_UE) ? 'U' : 'u', + (sw & FPUS_OE) ? 'O' : 'o', + (sw & FPUS_ZE) ? 'Z' : 'z', + (sw & FPUS_DE) ? 'D' : 'd', + (sw & FPUS_IE) ? 'I' : 'i'); +} + +static void do_fprem(long double a, long double b) +{ + const union float80u au = {.d = a}; + const union float80u bu = {.d = b}; + union float80u ru; + uint16_t sw; + + printf("A: S=%d Exp=%04x Int=%d (QNaN=%d) Sig=%016llx (%.06Le)\n", + au.ieee.negative, au.ieee.exponent, au.ieee.one, + au.ieee_nan.quiet_nan, (unsigned long long)au.ieee.mantissa, + a); + printf("B: S=%d Exp=%04x Int=%d (QNaN=%d) Sig=%016llx (%.06Le)\n", + bu.ieee.negative, bu.ieee.exponent, bu.ieee.one, + bu.ieee_nan.quiet_nan, (unsigned long long)bu.ieee.mantissa, + b); + fflush(stdout); + + fninit(); + ru.d = fprem(a, b, &sw); + psw(sw); + + printf("R : S=%d Exp=%04x Int=%d (QNaN=%d) Sig=%016llx (%.06Le)\n", + ru.ieee.negative, ru.ieee.exponent, ru.ieee.one, + ru.ieee_nan.quiet_nan, (unsigned long long)ru.ieee.mantissa, + ru.d); + + fninit(); + ru.d = fprem1(a, b, &sw); + psw(sw); + + printf("R1: S=%d Exp=%04x Int=%d (QNaN=%d) Sig=%016llx (%.06Le)\n", + ru.ieee.negative, ru.ieee.exponent, ru.ieee.one, + ru.ieee_nan.quiet_nan, (unsigned long long)ru.ieee.mantissa, + ru.d); + + printf("\n"); +} + +static void do_fprem_stack_underflow(void) +{ + const long double a = 1.0; + union float80u ru; + uint16_t sw; + + fninit(); + asm volatile ("fprem\n" + "fnstsw %1\n" + : "=t" (ru.d), "=m" (sw) + : "0" (a) + : "st(1)"); + psw(sw); + + printf("R: S=%d Exp=%04x Int=%d (QNaN=%d) Sig=%016llx (%.06Le)\n", + ru.ieee.negative, ru.ieee.exponent, ru.ieee.one, + ru.ieee_nan.quiet_nan, (unsigned long long)ru.ieee.mantissa, + ru.d); + printf("\n"); +} + +static void test_fprem_cases(void) +{ + printf("= stack underflow =\n"); + do_fprem_stack_underflow(); + + printf("= invalid operation =\n"); + do_fprem(s_nan.d, 1.0); + do_fprem(1.0, 0.0); + do_fprem(pos_inf.d, 1.0); + do_fprem(pseudo_pos_inf.d, 1.0); + + printf("= denormal =\n"); + do_fprem(pos_denorm.d, 1.0); + do_fprem(1.0, pos_denorm.d); + + /* printf("= underflow =\n"); */ + /* TODO: Is there a case where FPREM raises underflow? */ +} + +static void test_fprem_pairs(void) +{ + unsigned long long count; + + unsigned int negative_index_a = 0; + unsigned int negative_index_b = 0; + static const unsigned int negative_values[] = { + 0, + 1, + }; + + unsigned int exponent_index_a = 0; + unsigned int exponent_index_b = 0; + static const unsigned int exponent_values[] = { + 0, + 1, + 2, + IEEE854_LONG_DOUBLE_BIAS - 1, + IEEE854_LONG_DOUBLE_BIAS, + IEEE854_LONG_DOUBLE_BIAS + 1, + 0x7ffd, + 0x7ffe, + 0x7fff, + }; + + unsigned int one_index_a = 0; + unsigned int one_index_b = 0; + static const unsigned int one_values[] = { + 0, + 1, + }; + + unsigned int quiet_nan_index_a = 0; + unsigned int quiet_nan_index_b = 0; + static const unsigned int quiet_nan_values[] = { + 0, + 1, + }; + + unsigned int mantissa_index_a = 0; + unsigned int mantissa_index_b = 0; + static const unsigned long long mantissa_values[] = { + 0, + 1, + 2, + 0x3ffffffffffffffdULL, + 0x3ffffffffffffffeULL, + 0x3fffffffffffffffULL, + }; + + for (count = 0; ; ++count) { +#define INIT_FIELD(var, field) \ + .ieee_nan.field = field##_values[field##_index_##var] + const union float80u a = { + INIT_FIELD(a, negative), + INIT_FIELD(a, exponent), + INIT_FIELD(a, one), + INIT_FIELD(a, quiet_nan), + INIT_FIELD(a, mantissa), + }; + const union float80u b = { + INIT_FIELD(b, negative), + INIT_FIELD(b, exponent), + INIT_FIELD(b, one), + INIT_FIELD(b, quiet_nan), + INIT_FIELD(b, mantissa), + }; +#undef INIT_FIELD + + do_fprem(a.d, b.d); + + int carry = 1; +#define CARRY_INTO(var, field) do { \ + if (carry) { \ + if (++field##_index_##var == ARRAY_SIZE(field##_values)) { \ + field##_index_##var = 0; \ + } else { \ + carry = 0; \ + } \ + } \ + } while (0) + CARRY_INTO(b, mantissa); + CARRY_INTO(b, quiet_nan); + CARRY_INTO(b, one); + CARRY_INTO(b, exponent); + CARRY_INTO(b, negative); + CARRY_INTO(a, mantissa); + CARRY_INTO(a, quiet_nan); + CARRY_INTO(a, one); + CARRY_INTO(a, exponent); + CARRY_INTO(a, negative); +#undef CARRY_INTO + + if (carry) { + break; + } + } + + fprintf(stderr, "test-i386-fprem: tested %llu cases\n", count); +} + +int main(int argc, char **argv) +{ + test_fprem_cases(); + test_fprem_pairs(); + return 0; +} |