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Diffstat (limited to 'REORG.TODO/sysdeps/powerpc/power4/fpu/mpa.c')
| -rw-r--r-- | REORG.TODO/sysdeps/powerpc/power4/fpu/mpa.c | 214 |
1 files changed, 214 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/powerpc/power4/fpu/mpa.c b/REORG.TODO/sysdeps/powerpc/power4/fpu/mpa.c new file mode 100644 index 0000000000..0a0f7175b4 --- /dev/null +++ b/REORG.TODO/sysdeps/powerpc/power4/fpu/mpa.c @@ -0,0 +1,214 @@ + +/* + * IBM Accurate Mathematical Library + * written by International Business Machines Corp. + * Copyright (C) 2001-2017 Free Software Foundation, Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU Lesser General Public License as published by + * the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public License + * along with this program; if not, see <http://www.gnu.org/licenses/>. + */ + +/* Define __mul and __sqr and use the rest from generic code. */ +#define NO__MUL +#define NO__SQR + +#include <sysdeps/ieee754/dbl-64/mpa.c> + +/* Multiply *X and *Y and store result in *Z. X and Y may overlap but not X + and Z or Y and Z. For P in [1, 2, 3], the exact result is truncated to P + digits. In case P > 3 the error is bounded by 1.001 ULP. */ +void +__mul (const mp_no *x, const mp_no *y, mp_no *z, int p) +{ + long i, i1, i2, j, k, k2; + long p2 = p; + double u, zk, zk2; + + /* Is z=0? */ + if (__glibc_unlikely (X[0] * Y[0] == 0)) + { + Z[0] = 0; + return; + } + + /* Multiply, add and carry */ + k2 = (p2 < 3) ? p2 + p2 : p2 + 3; + zk = Z[k2] = 0; + for (k = k2; k > 1;) + { + if (k > p2) + { + i1 = k - p2; + i2 = p2 + 1; + } + else + { + i1 = 1; + i2 = k; + } +#if 1 + /* Rearrange this inner loop to allow the fmadd instructions to be + independent and execute in parallel on processors that have + dual symmetrical FP pipelines. */ + if (i1 < (i2 - 1)) + { + /* Make sure we have at least 2 iterations. */ + if (((i2 - i1) & 1L) == 1L) + { + /* Handle the odd iterations case. */ + zk2 = x->d[i2 - 1] * y->d[i1]; + } + else + zk2 = 0.0; + /* Do two multiply/adds per loop iteration, using independent + accumulators; zk and zk2. */ + for (i = i1, j = i2 - 1; i < i2 - 1; i += 2, j -= 2) + { + zk += x->d[i] * y->d[j]; + zk2 += x->d[i + 1] * y->d[j - 1]; + } + zk += zk2; /* Final sum. */ + } + else + { + /* Special case when iterations is 1. */ + zk += x->d[i1] * y->d[i1]; + } +#else + /* The original code. */ + for (i = i1, j = i2 - 1; i < i2; i++, j--) + zk += X[i] * Y[j]; +#endif + + u = (zk + CUTTER) - CUTTER; + if (u > zk) + u -= RADIX; + Z[k] = zk - u; + zk = u * RADIXI; + --k; + } + Z[k] = zk; + + int e = EX + EY; + /* Is there a carry beyond the most significant digit? */ + if (Z[1] == 0) + { + for (i = 1; i <= p2; i++) + Z[i] = Z[i + 1]; + e--; + } + + EZ = e; + Z[0] = X[0] * Y[0]; +} + +/* Square *X and store result in *Y. X and Y may not overlap. For P in + [1, 2, 3], the exact result is truncated to P digits. In case P > 3 the + error is bounded by 1.001 ULP. This is a faster special case of + multiplication. */ +void +__sqr (const mp_no *x, mp_no *y, int p) +{ + long i, j, k, ip; + double u, yk; + + /* Is z=0? */ + if (__glibc_unlikely (X[0] == 0)) + { + Y[0] = 0; + return; + } + + /* We need not iterate through all X's since it's pointless to + multiply zeroes. */ + for (ip = p; ip > 0; ip--) + if (X[ip] != 0) + break; + + k = (__glibc_unlikely (p < 3)) ? p + p : p + 3; + + while (k > 2 * ip + 1) + Y[k--] = 0; + + yk = 0; + + while (k > p) + { + double yk2 = 0.0; + long lim = k / 2; + + if (k % 2 == 0) + { + yk += X[lim] * X[lim]; + lim--; + } + + /* In __mul, this loop (and the one within the next while loop) run + between a range to calculate the mantissa as follows: + + Z[k] = X[k] * Y[n] + X[k+1] * Y[n-1] ... + X[n-1] * Y[k+1] + + X[n] * Y[k] + + For X == Y, we can get away with summing halfway and doubling the + result. For cases where the range size is even, the mid-point needs + to be added separately (above). */ + for (i = k - p, j = p; i <= lim; i++, j--) + yk2 += X[i] * X[j]; + + yk += 2.0 * yk2; + + u = (yk + CUTTER) - CUTTER; + if (u > yk) + u -= RADIX; + Y[k--] = yk - u; + yk = u * RADIXI; + } + + while (k > 1) + { + double yk2 = 0.0; + long lim = k / 2; + + if (k % 2 == 0) + { + yk += X[lim] * X[lim]; + lim--; + } + + /* Likewise for this loop. */ + for (i = 1, j = k - 1; i <= lim; i++, j--) + yk2 += X[i] * X[j]; + + yk += 2.0 * yk2; + + u = (yk + CUTTER) - CUTTER; + if (u > yk) + u -= RADIX; + Y[k--] = yk - u; + yk = u * RADIXI; + } + Y[k] = yk; + + /* Squares are always positive. */ + Y[0] = 1.0; + + int e = EX * 2; + /* Is there a carry beyond the most significant digit? */ + if (__glibc_unlikely (Y[1] == 0)) + { + for (i = 1; i <= p; i++) + Y[i] = Y[i + 1]; + e--; + } + EY = e; +} |