^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0-or-later
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) fp_arith.c: floating-point math routines for the Linux-m68k
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) floating point emulator.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) Copyright (c) 1998-1999 David Huggins-Daines.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) Somewhat based on the AlphaLinux floating point emulator, by David
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) Mosberger-Tang.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include "fp_emu.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include "multi_arith.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include "fp_arith.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) const struct fp_ext fp_QNaN =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) .exp = 0x7fff,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) .mant = { .m64 = ~0 }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) const struct fp_ext fp_Inf =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) .exp = 0x7fff,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) /* let's start with the easy ones */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) struct fp_ext *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) fp_fabs(struct fp_ext *dest, struct fp_ext *src)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) dprint(PINSTR, "fabs\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) fp_monadic_check(dest, src);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) dest->sign = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) return dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) struct fp_ext *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) fp_fneg(struct fp_ext *dest, struct fp_ext *src)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) dprint(PINSTR, "fneg\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) fp_monadic_check(dest, src);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) dest->sign = !dest->sign;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) return dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) /* Now, the slightly harder ones */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) /* fp_fadd: Implements the kernel of the FADD, FSADD, FDADD, FSUB,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) FDSUB, and FCMP instructions. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) struct fp_ext *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) fp_fadd(struct fp_ext *dest, struct fp_ext *src)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) int diff;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) dprint(PINSTR, "fadd\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) fp_dyadic_check(dest, src);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) if (IS_INF(dest)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) /* infinity - infinity == NaN */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) if (IS_INF(src) && (src->sign != dest->sign))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) fp_set_nan(dest);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) return dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) if (IS_INF(src)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) fp_copy_ext(dest, src);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) return dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) if (IS_ZERO(dest)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) if (IS_ZERO(src)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) if (src->sign != dest->sign) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) if (FPDATA->rnd == FPCR_ROUND_RM)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) dest->sign = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) dest->sign = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) } else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) fp_copy_ext(dest, src);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) return dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) dest->lowmant = src->lowmant = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) if ((diff = dest->exp - src->exp) > 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) fp_denormalize(src, diff);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) else if ((diff = -diff) > 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) fp_denormalize(dest, diff);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) if (dest->sign == src->sign) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) if (fp_addmant(dest, src))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) if (!fp_addcarry(dest))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) return dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) if (dest->mant.m64 < src->mant.m64) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) fp_submant(dest, src, dest);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) dest->sign = !dest->sign;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) } else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) fp_submant(dest, dest, src);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) return dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) /* fp_fsub: Implements the kernel of the FSUB, FSSUB, and FDSUB
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) instructions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) Remember that the arguments are in assembler-syntax order! */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) struct fp_ext *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) fp_fsub(struct fp_ext *dest, struct fp_ext *src)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) dprint(PINSTR, "fsub ");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) src->sign = !src->sign;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) return fp_fadd(dest, src);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) struct fp_ext *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) fp_fcmp(struct fp_ext *dest, struct fp_ext *src)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) dprint(PINSTR, "fcmp ");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) FPDATA->temp[1] = *dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) src->sign = !src->sign;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) return fp_fadd(&FPDATA->temp[1], src);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) struct fp_ext *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) fp_ftst(struct fp_ext *dest, struct fp_ext *src)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) dprint(PINSTR, "ftst\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) (void)dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) return src;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) struct fp_ext *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) fp_fmul(struct fp_ext *dest, struct fp_ext *src)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) union fp_mant128 temp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) int exp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) dprint(PINSTR, "fmul\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) fp_dyadic_check(dest, src);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) /* calculate the correct sign now, as it's necessary for infinities */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) dest->sign = src->sign ^ dest->sign;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) /* Handle infinities */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) if (IS_INF(dest)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) if (IS_ZERO(src))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) fp_set_nan(dest);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) return dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) if (IS_INF(src)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) if (IS_ZERO(dest))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) fp_set_nan(dest);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) fp_copy_ext(dest, src);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) return dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) /* Of course, as we all know, zero * anything = zero. You may
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) not have known that it might be a positive or negative
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) zero... */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) if (IS_ZERO(dest) || IS_ZERO(src)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) dest->exp = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) dest->mant.m64 = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) dest->lowmant = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) return dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) exp = dest->exp + src->exp - 0x3ffe;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) /* shift up the mantissa for denormalized numbers,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) so that the highest bit is set, this makes the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) shift of the result below easier */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) if ((long)dest->mant.m32[0] >= 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) exp -= fp_overnormalize(dest);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) if ((long)src->mant.m32[0] >= 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) exp -= fp_overnormalize(src);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) /* now, do a 64-bit multiply with expansion */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) fp_multiplymant(&temp, dest, src);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) /* normalize it back to 64 bits and stuff it back into the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) destination struct */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) if ((long)temp.m32[0] > 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) exp--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) fp_putmant128(dest, &temp, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) } else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) fp_putmant128(dest, &temp, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) if (exp >= 0x7fff) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) fp_set_ovrflw(dest);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) return dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) dest->exp = exp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) if (exp < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) fp_set_sr(FPSR_EXC_UNFL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) fp_denormalize(dest, -exp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) return dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) /* fp_fdiv: Implements the "kernel" of the FDIV, FSDIV, FDDIV and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) FSGLDIV instructions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) Note that the order of the operands is counter-intuitive: instead
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) of src / dest, the result is actually dest / src. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) struct fp_ext *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) fp_fdiv(struct fp_ext *dest, struct fp_ext *src)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) union fp_mant128 temp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) int exp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) dprint(PINSTR, "fdiv\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) fp_dyadic_check(dest, src);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) /* calculate the correct sign now, as it's necessary for infinities */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) dest->sign = src->sign ^ dest->sign;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) /* Handle infinities */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) if (IS_INF(dest)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) /* infinity / infinity = NaN (quiet, as always) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) if (IS_INF(src))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) fp_set_nan(dest);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) /* infinity / anything else = infinity (with approprate sign) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) return dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) if (IS_INF(src)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) /* anything / infinity = zero (with appropriate sign) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) dest->exp = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) dest->mant.m64 = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) dest->lowmant = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) return dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) /* zeroes */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) if (IS_ZERO(dest)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) /* zero / zero = NaN */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) if (IS_ZERO(src))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) fp_set_nan(dest);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) /* zero / anything else = zero */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) return dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) if (IS_ZERO(src)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) /* anything / zero = infinity (with appropriate sign) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) fp_set_sr(FPSR_EXC_DZ);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) dest->exp = 0x7fff;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) dest->mant.m64 = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) return dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) exp = dest->exp - src->exp + 0x3fff;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) /* shift up the mantissa for denormalized numbers,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) so that the highest bit is set, this makes lots
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) of things below easier */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) if ((long)dest->mant.m32[0] >= 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) exp -= fp_overnormalize(dest);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) if ((long)src->mant.m32[0] >= 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) exp -= fp_overnormalize(src);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) /* now, do the 64-bit divide */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) fp_dividemant(&temp, dest, src);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) /* normalize it back to 64 bits and stuff it back into the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) destination struct */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) if (!temp.m32[0]) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) exp--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) fp_putmant128(dest, &temp, 32);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) } else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) fp_putmant128(dest, &temp, 31);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) if (exp >= 0x7fff) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) fp_set_ovrflw(dest);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) return dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) dest->exp = exp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) if (exp < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) fp_set_sr(FPSR_EXC_UNFL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) fp_denormalize(dest, -exp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) return dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) struct fp_ext *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) fp_fsglmul(struct fp_ext *dest, struct fp_ext *src)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) int exp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) dprint(PINSTR, "fsglmul\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) fp_dyadic_check(dest, src);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) /* calculate the correct sign now, as it's necessary for infinities */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) dest->sign = src->sign ^ dest->sign;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) /* Handle infinities */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) if (IS_INF(dest)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) if (IS_ZERO(src))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) fp_set_nan(dest);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) return dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) if (IS_INF(src)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) if (IS_ZERO(dest))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) fp_set_nan(dest);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) fp_copy_ext(dest, src);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) return dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) /* Of course, as we all know, zero * anything = zero. You may
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) not have known that it might be a positive or negative
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) zero... */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) if (IS_ZERO(dest) || IS_ZERO(src)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) dest->exp = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) dest->mant.m64 = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) dest->lowmant = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) return dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) exp = dest->exp + src->exp - 0x3ffe;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) /* do a 32-bit multiply */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) fp_mul64(dest->mant.m32[0], dest->mant.m32[1],
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) dest->mant.m32[0] & 0xffffff00,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) src->mant.m32[0] & 0xffffff00);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) if (exp >= 0x7fff) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) fp_set_ovrflw(dest);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) return dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) dest->exp = exp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) if (exp < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) fp_set_sr(FPSR_EXC_UNFL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) fp_denormalize(dest, -exp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) return dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) struct fp_ext *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) fp_fsgldiv(struct fp_ext *dest, struct fp_ext *src)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) int exp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) unsigned long quot, rem;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) dprint(PINSTR, "fsgldiv\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) fp_dyadic_check(dest, src);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) /* calculate the correct sign now, as it's necessary for infinities */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) dest->sign = src->sign ^ dest->sign;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) /* Handle infinities */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) if (IS_INF(dest)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) /* infinity / infinity = NaN (quiet, as always) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) if (IS_INF(src))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) fp_set_nan(dest);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) /* infinity / anything else = infinity (with approprate sign) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) return dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) if (IS_INF(src)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) /* anything / infinity = zero (with appropriate sign) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) dest->exp = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) dest->mant.m64 = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) dest->lowmant = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) return dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) /* zeroes */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) if (IS_ZERO(dest)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) /* zero / zero = NaN */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) if (IS_ZERO(src))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) fp_set_nan(dest);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) /* zero / anything else = zero */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) return dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) if (IS_ZERO(src)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) /* anything / zero = infinity (with appropriate sign) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) fp_set_sr(FPSR_EXC_DZ);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) dest->exp = 0x7fff;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) dest->mant.m64 = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) return dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) exp = dest->exp - src->exp + 0x3fff;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) dest->mant.m32[0] &= 0xffffff00;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416) src->mant.m32[0] &= 0xffffff00;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) /* do the 32-bit divide */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) if (dest->mant.m32[0] >= src->mant.m32[0]) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) fp_sub64(dest->mant, src->mant);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) fp_div64(quot, rem, dest->mant.m32[0], 0, src->mant.m32[0]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) dest->mant.m32[0] = 0x80000000 | (quot >> 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) dest->mant.m32[1] = (quot & 1) | rem; /* only for rounding */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) fp_div64(quot, rem, dest->mant.m32[0], 0, src->mant.m32[0]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) dest->mant.m32[0] = quot;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427) dest->mant.m32[1] = rem; /* only for rounding */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428) exp--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) if (exp >= 0x7fff) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432) fp_set_ovrflw(dest);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433) return dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435) dest->exp = exp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) if (exp < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437) fp_set_sr(FPSR_EXC_UNFL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438) fp_denormalize(dest, -exp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) return dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) /* fp_roundint: Internal rounding function for use by several of these
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) emulated instructions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) This one rounds off the fractional part using the rounding mode
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448) specified. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450) static void fp_roundint(struct fp_ext *dest, int mode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452) union fp_mant64 oldmant;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453) unsigned long mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455) if (!fp_normalize_ext(dest))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458) /* infinities and zeroes */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459) if (IS_INF(dest) || IS_ZERO(dest))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462) /* first truncate the lower bits */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463) oldmant = dest->mant;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) switch (dest->exp) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465) case 0 ... 0x3ffe:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466) dest->mant.m64 = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468) case 0x3fff ... 0x401e:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469) dest->mant.m32[0] &= 0xffffffffU << (0x401e - dest->exp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470) dest->mant.m32[1] = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471) if (oldmant.m64 == dest->mant.m64)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474) case 0x401f ... 0x403e:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 475) dest->mant.m32[1] &= 0xffffffffU << (0x403e - dest->exp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 476) if (oldmant.m32[1] == dest->mant.m32[1])
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 477) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 478) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 479) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 480) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 481) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 482) fp_set_sr(FPSR_EXC_INEX2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 483)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 484) /* We might want to normalize upwards here... however, since
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 485) we know that this is only called on the output of fp_fdiv,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 486) or with the input to fp_fint or fp_fintrz, and the inputs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 487) to all these functions are either normal or denormalized
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 488) (no subnormals allowed!), there's really no need.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 489)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 490) In the case of fp_fdiv, observe that 0x80000000 / 0xffff =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 491) 0xffff8000, and the same holds for 128-bit / 64-bit. (i.e. the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 492) smallest possible normal dividend and the largest possible normal
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 493) divisor will still produce a normal quotient, therefore, (normal
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 494) << 64) / normal is normal in all cases) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 495)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 496) switch (mode) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 497) case FPCR_ROUND_RN:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 498) switch (dest->exp) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 499) case 0 ... 0x3ffd:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 500) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 501) case 0x3ffe:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 502) /* As noted above, the input is always normal, so the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 503) guard bit (bit 63) is always set. therefore, the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 504) only case in which we will NOT round to 1.0 is when
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 505) the input is exactly 0.5. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 506) if (oldmant.m64 == (1ULL << 63))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 507) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 508) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 509) case 0x3fff ... 0x401d:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 510) mask = 1 << (0x401d - dest->exp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 511) if (!(oldmant.m32[0] & mask))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 512) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 513) if (oldmant.m32[0] & (mask << 1))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 514) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 515) if (!(oldmant.m32[0] << (dest->exp - 0x3ffd)) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 516) !oldmant.m32[1])
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 517) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 518) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 519) case 0x401e:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 520) if (oldmant.m32[1] & 0x80000000)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 521) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 522) if (oldmant.m32[0] & 1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 523) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 524) if (!(oldmant.m32[1] << 1))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 525) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 526) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 527) case 0x401f ... 0x403d:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 528) mask = 1 << (0x403d - dest->exp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 529) if (!(oldmant.m32[1] & mask))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 530) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 531) if (oldmant.m32[1] & (mask << 1))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 532) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 533) if (!(oldmant.m32[1] << (dest->exp - 0x401d)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 534) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 535) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 536) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 537) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 538) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 539) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 540) case FPCR_ROUND_RZ:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 541) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 542) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 543) if (dest->sign ^ (mode - FPCR_ROUND_RM))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 544) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 545) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 546) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 547)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 548) switch (dest->exp) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 549) case 0 ... 0x3ffe:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 550) dest->exp = 0x3fff;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 551) dest->mant.m64 = 1ULL << 63;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 552) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 553) case 0x3fff ... 0x401e:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 554) mask = 1 << (0x401e - dest->exp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 555) if (dest->mant.m32[0] += mask)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 556) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 557) dest->mant.m32[0] = 0x80000000;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 558) dest->exp++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 559) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 560) case 0x401f ... 0x403e:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 561) mask = 1 << (0x403e - dest->exp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 562) if (dest->mant.m32[1] += mask)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 563) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 564) if (dest->mant.m32[0] += 1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 565) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 566) dest->mant.m32[0] = 0x80000000;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 567) dest->exp++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 568) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 569) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 570) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 571)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 572) /* modrem_kernel: Implementation of the FREM and FMOD instructions
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 573) (which are exactly the same, except for the rounding used on the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 574) intermediate value) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 575)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 576) static struct fp_ext *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 577) modrem_kernel(struct fp_ext *dest, struct fp_ext *src, int mode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 578) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 579) struct fp_ext tmp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 580)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 581) fp_dyadic_check(dest, src);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 582)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 583) /* Infinities and zeros */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 584) if (IS_INF(dest) || IS_ZERO(src)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 585) fp_set_nan(dest);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 586) return dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 587) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 588) if (IS_ZERO(dest) || IS_INF(src))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 589) return dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 590)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 591) /* FIXME: there is almost certainly a smarter way to do this */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 592) fp_copy_ext(&tmp, dest);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 593) fp_fdiv(&tmp, src); /* NOTE: src might be modified */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 594) fp_roundint(&tmp, mode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 595) fp_fmul(&tmp, src);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 596) fp_fsub(dest, &tmp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 597)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 598) /* set the quotient byte */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 599) fp_set_quotient((dest->mant.m64 & 0x7f) | (dest->sign << 7));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 600) return dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 601) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 602)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 603) /* fp_fmod: Implements the kernel of the FMOD instruction.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 604)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 605) Again, the argument order is backwards. The result, as defined in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 606) the Motorola manuals, is:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 607)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 608) fmod(src,dest) = (dest - (src * floor(dest / src))) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 609)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 610) struct fp_ext *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 611) fp_fmod(struct fp_ext *dest, struct fp_ext *src)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 612) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 613) dprint(PINSTR, "fmod\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 614) return modrem_kernel(dest, src, FPCR_ROUND_RZ);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 615) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 616)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 617) /* fp_frem: Implements the kernel of the FREM instruction.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 618)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 619) frem(src,dest) = (dest - (src * round(dest / src)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 620) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 621)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 622) struct fp_ext *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 623) fp_frem(struct fp_ext *dest, struct fp_ext *src)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 624) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 625) dprint(PINSTR, "frem\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 626) return modrem_kernel(dest, src, FPCR_ROUND_RN);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 627) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 628)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 629) struct fp_ext *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 630) fp_fint(struct fp_ext *dest, struct fp_ext *src)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 631) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 632) dprint(PINSTR, "fint\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 633)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 634) fp_copy_ext(dest, src);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 635)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 636) fp_roundint(dest, FPDATA->rnd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 637)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 638) return dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 639) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 640)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 641) struct fp_ext *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 642) fp_fintrz(struct fp_ext *dest, struct fp_ext *src)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 643) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 644) dprint(PINSTR, "fintrz\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 645)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 646) fp_copy_ext(dest, src);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 647)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 648) fp_roundint(dest, FPCR_ROUND_RZ);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 649)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 650) return dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 651) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 652)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 653) struct fp_ext *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 654) fp_fscale(struct fp_ext *dest, struct fp_ext *src)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 655) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 656) int scale, oldround;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 657)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 658) dprint(PINSTR, "fscale\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 659)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 660) fp_dyadic_check(dest, src);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 661)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 662) /* Infinities */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 663) if (IS_INF(src)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 664) fp_set_nan(dest);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 665) return dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 666) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 667) if (IS_INF(dest))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 668) return dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 669)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 670) /* zeroes */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 671) if (IS_ZERO(src) || IS_ZERO(dest))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 672) return dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 673)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 674) /* Source exponent out of range */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 675) if (src->exp >= 0x400c) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 676) fp_set_ovrflw(dest);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 677) return dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 678) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 679)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 680) /* src must be rounded with round to zero. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 681) oldround = FPDATA->rnd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 682) FPDATA->rnd = FPCR_ROUND_RZ;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 683) scale = fp_conv_ext2long(src);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 684) FPDATA->rnd = oldround;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 685)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 686) /* new exponent */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 687) scale += dest->exp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 688)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 689) if (scale >= 0x7fff) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 690) fp_set_ovrflw(dest);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 691) } else if (scale <= 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 692) fp_set_sr(FPSR_EXC_UNFL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 693) fp_denormalize(dest, -scale);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 694) } else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 695) dest->exp = scale;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 696)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 697) return dest;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 698) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 699)
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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