--- /dev/null
+/* Copyright (C) 2007, 2009 Free Software Foundation, Inc.
+
+This file is part of GCC.
+
+GCC 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 3, or (at your option) any later
+version.
+
+GCC 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.
+
+Under Section 7 of GPL version 3, you are granted additional
+permissions described in the GCC Runtime Library Exception, version
+3.1, as published by the Free Software Foundation.
+
+You should have received a copy of the GNU General Public License and
+a copy of the GCC Runtime Library Exception along with this program;
+see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+<http://www.gnu.org/licenses/>. */
+
+/*****************************************************************************
+ * BID64 remainder
+ *****************************************************************************
+ *
+ * Algorithm description:
+ *
+ * if(exponent_x < exponent_y)
+ * scale coefficient_y so exponents are aligned
+ * perform coefficient divide (64-bit integer divide), unless
+ * coefficient_y is longer than 64 bits (clearly larger
+ * than coefficient_x)
+ * else // exponent_x > exponent_y
+ * use a loop to scale coefficient_x to 18_digits, divide by
+ * coefficient_y (64-bit integer divide), calculate remainder
+ * as new_coefficient_x and repeat until final remainder is obtained
+ * (when new_exponent_x < exponent_y)
+ *
+ ****************************************************************************/
+
+#include "bid_internal.h"
+
+#define MAX_FORMAT_DIGITS 16
+#define DECIMAL_EXPONENT_BIAS 398
+#define MASK_BINARY_EXPONENT 0x7ff0000000000000ull
+#define BINARY_EXPONENT_BIAS 0x3ff
+#define UPPER_EXPON_LIMIT 51
+
+#if DECIMAL_CALL_BY_REFERENCE
+
+void
+bid64_rem (UINT64 * pres, UINT64 * px,
+ UINT64 *
+ py _EXC_FLAGS_PARAM _EXC_MASKS_PARAM _EXC_INFO_PARAM) {
+ UINT64 x, y;
+#else
+
+UINT64
+bid64_rem (UINT64 x,
+ UINT64 y _EXC_FLAGS_PARAM _EXC_MASKS_PARAM _EXC_INFO_PARAM) {
+#endif
+ UINT128 CY;
+ UINT64 sign_x, sign_y, coefficient_x, coefficient_y, res;
+ UINT64 Q, R, R2, T, valid_y, valid_x;
+ int_float tempx;
+ int exponent_x, exponent_y, bin_expon, e_scale;
+ int digits_x, diff_expon;
+
+#if DECIMAL_CALL_BY_REFERENCE
+ x = *px;
+ y = *py;
+#endif
+
+ valid_y = unpack_BID64 (&sign_y, &exponent_y, &coefficient_y, y);
+ valid_x = unpack_BID64 (&sign_x, &exponent_x, &coefficient_x, x);
+
+ // unpack arguments, check for NaN or Infinity
+ if (!valid_x) {
+ // x is Inf. or NaN or 0
+#ifdef SET_STATUS_FLAGS
+ if ((y & SNAN_MASK64) == SNAN_MASK64) // y is sNaN
+ __set_status_flags (pfpsf, INVALID_EXCEPTION);
+#endif
+
+ // test if x is NaN
+ if ((x & 0x7c00000000000000ull) == 0x7c00000000000000ull) {
+#ifdef SET_STATUS_FLAGS
+ if (((x & SNAN_MASK64) == SNAN_MASK64))
+ __set_status_flags (pfpsf, INVALID_EXCEPTION);
+#endif
+ res = coefficient_x & QUIET_MASK64;;
+ BID_RETURN (res);
+ }
+ // x is Infinity?
+ if ((x & 0x7800000000000000ull) == 0x7800000000000000ull) {
+ if (((y & NAN_MASK64) != NAN_MASK64)) {
+#ifdef SET_STATUS_FLAGS
+ __set_status_flags (pfpsf, INVALID_EXCEPTION);
+#endif
+ // return NaN
+ res = 0x7c00000000000000ull;
+ BID_RETURN (res);
+ }
+ }
+ // x is 0
+ // return x if y != 0
+ if (((y & 0x7800000000000000ull) < 0x7800000000000000ull) &&
+ coefficient_y) {
+ if ((y & 0x6000000000000000ull) == 0x6000000000000000ull)
+ exponent_y = (y >> 51) & 0x3ff;
+ else
+ exponent_y = (y >> 53) & 0x3ff;
+
+ if (exponent_y < exponent_x)
+ exponent_x = exponent_y;
+
+ x = exponent_x;
+ x <<= 53;
+
+ res = x | sign_x;
+ BID_RETURN (res);
+ }
+
+ }
+ if (!valid_y) {
+ // y is Inf. or NaN
+
+ // test if y is NaN
+ if ((y & 0x7c00000000000000ull) == 0x7c00000000000000ull) {
+#ifdef SET_STATUS_FLAGS
+ if (((y & SNAN_MASK64) == SNAN_MASK64))
+ __set_status_flags (pfpsf, INVALID_EXCEPTION);
+#endif
+ res = coefficient_y & QUIET_MASK64;;
+ BID_RETURN (res);
+ }
+ // y is Infinity?
+ if ((y & 0x7800000000000000ull) == 0x7800000000000000ull) {
+ res = very_fast_get_BID64 (sign_x, exponent_x, coefficient_x);
+ BID_RETURN (res);
+ }
+ // y is 0, return NaN
+ {
+#ifdef SET_STATUS_FLAGS
+ __set_status_flags (pfpsf, INVALID_EXCEPTION);
+#endif
+ res = 0x7c00000000000000ull;
+ BID_RETURN (res);
+ }
+ }
+
+
+ diff_expon = exponent_x - exponent_y;
+ if (diff_expon <= 0) {
+ diff_expon = -diff_expon;
+
+ if (diff_expon > 16) {
+ // |x|<|y| in this case
+ res = x;
+ BID_RETURN (res);
+ }
+ // set exponent of y to exponent_x, scale coefficient_y
+ T = power10_table_128[diff_expon].w[0];
+ __mul_64x64_to_128 (CY, coefficient_y, T);
+
+ if (CY.w[1] || CY.w[0] > (coefficient_x << 1)) {
+ res = x;
+ BID_RETURN (res);
+ }
+
+ Q = coefficient_x / CY.w[0];
+ R = coefficient_x - Q * CY.w[0];
+
+ R2 = R + R;
+ if (R2 > CY.w[0] || (R2 == CY.w[0] && (Q & 1))) {
+ R = CY.w[0] - R;
+ sign_x ^= 0x8000000000000000ull;
+ }
+
+ res = very_fast_get_BID64 (sign_x, exponent_x, R);
+ BID_RETURN (res);
+ }
+
+
+ while (diff_expon > 0) {
+ // get number of digits in coeff_x
+ tempx.d = (float) coefficient_x;
+ bin_expon = ((tempx.i >> 23) & 0xff) - 0x7f;
+ digits_x = estimate_decimal_digits[bin_expon];
+ // will not use this test, dividend will have 18 or 19 digits
+ //if(coefficient_x >= power10_table_128[digits_x].w[0])
+ // digits_x++;
+
+ e_scale = 18 - digits_x;
+ if (diff_expon >= e_scale) {
+ diff_expon -= e_scale;
+ } else {
+ e_scale = diff_expon;
+ diff_expon = 0;
+ }
+
+ // scale dividend to 18 or 19 digits
+ coefficient_x *= power10_table_128[e_scale].w[0];
+
+ // quotient
+ Q = coefficient_x / coefficient_y;
+ // remainder
+ coefficient_x -= Q * coefficient_y;
+
+ // check for remainder == 0
+ if (!coefficient_x) {
+ res = very_fast_get_BID64_small_mantissa (sign_x, exponent_y, 0);
+ BID_RETURN (res);
+ }
+ }
+
+ R2 = coefficient_x + coefficient_x;
+ if (R2 > coefficient_y || (R2 == coefficient_y && (Q & 1))) {
+ coefficient_x = coefficient_y - coefficient_x;
+ sign_x ^= 0x8000000000000000ull;
+ }
+
+ res = very_fast_get_BID64 (sign_x, exponent_y, coefficient_x);
+ BID_RETURN (res);
+
+}
projects / msp430-gcc.git / blobdiff