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Diffstat (limited to 'gcc-4.9/libgcc/config/spu/divv2df3.c')
| -rw-r--r-- | gcc-4.9/libgcc/config/spu/divv2df3.c | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/gcc-4.9/libgcc/config/spu/divv2df3.c b/gcc-4.9/libgcc/config/spu/divv2df3.c new file mode 100644 index 000000000..aca64d2a4 --- /dev/null +++ b/gcc-4.9/libgcc/config/spu/divv2df3.c @@ -0,0 +1,195 @@ +/* Copyright (C) 2009-2014 Free Software Foundation, Inc. + + This file 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 of the License, or (at your option) + any later version. + + This file 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/>. */ + +#include <spu_intrinsics.h> + +vector double __divv2df3 (vector double a_in, vector double b_in); + +/* __divv2df3 divides the vector dividend a by the vector divisor b and + returns the resulting vector quotient. Maximum error about 0.5 ulp + over entire double range including denorms, compared to true result + in round-to-nearest rounding mode. Handles Inf or NaN operands and + results correctly. */ + +vector double +__divv2df3 (vector double a_in, vector double b_in) +{ + /* Variables */ + vec_int4 exp, exp_bias; + vec_uint4 no_underflow, overflow; + vec_float4 mant_bf, inv_bf; + vec_ullong2 exp_a, exp_b; + vec_ullong2 a_nan, a_zero, a_inf, a_denorm, a_denorm0; + vec_ullong2 b_nan, b_zero, b_inf, b_denorm, b_denorm0; + vec_ullong2 nan; + vec_uint4 a_exp, b_exp; + vec_ullong2 a_mant_0, b_mant_0; + vec_ullong2 a_exp_1s, b_exp_1s; + vec_ullong2 sign_exp_mask; + + vec_double2 a, b; + vec_double2 mant_a, mant_b, inv_b, q0, q1, q2, mult; + + /* Constants */ + vec_uint4 exp_mask_u32 = spu_splats((unsigned int)0x7FF00000); + vec_uchar16 splat_hi = (vec_uchar16){0,1,2,3, 0,1,2,3, 8, 9,10,11, 8,9,10,11}; + vec_uchar16 swap_32 = (vec_uchar16){4,5,6,7, 0,1,2,3, 12,13,14,15, 8,9,10,11}; + vec_ullong2 exp_mask = spu_splats(0x7FF0000000000000ULL); + vec_ullong2 sign_mask = spu_splats(0x8000000000000000ULL); + vec_float4 onef = spu_splats(1.0f); + vec_double2 one = spu_splats(1.0); + vec_double2 exp_53 = (vec_double2)spu_splats(0x0350000000000000ULL); + + sign_exp_mask = spu_or(sign_mask, exp_mask); + + /* Extract the floating point components from each of the operands including + * exponent and mantissa. + */ + a_exp = (vec_uint4)spu_and((vec_uint4)a_in, exp_mask_u32); + a_exp = spu_shuffle(a_exp, a_exp, splat_hi); + b_exp = (vec_uint4)spu_and((vec_uint4)b_in, exp_mask_u32); + b_exp = spu_shuffle(b_exp, b_exp, splat_hi); + + a_mant_0 = (vec_ullong2)spu_cmpeq((vec_uint4)spu_andc((vec_ullong2)a_in, sign_exp_mask), 0); + a_mant_0 = spu_and(a_mant_0, spu_shuffle(a_mant_0, a_mant_0, swap_32)); + + b_mant_0 = (vec_ullong2)spu_cmpeq((vec_uint4)spu_andc((vec_ullong2)b_in, sign_exp_mask), 0); + b_mant_0 = spu_and(b_mant_0, spu_shuffle(b_mant_0, b_mant_0, swap_32)); + + a_exp_1s = (vec_ullong2)spu_cmpeq(a_exp, exp_mask_u32); + b_exp_1s = (vec_ullong2)spu_cmpeq(b_exp, exp_mask_u32); + + /* Identify all possible special values that must be accommodated including: + * +-denorm, +-0, +-infinity, and NaNs. + */ + a_denorm0= (vec_ullong2)spu_cmpeq(a_exp, 0); + a_nan = spu_andc(a_exp_1s, a_mant_0); + a_zero = spu_and (a_denorm0, a_mant_0); + a_inf = spu_and (a_exp_1s, a_mant_0); + a_denorm = spu_andc(a_denorm0, a_zero); + + b_denorm0= (vec_ullong2)spu_cmpeq(b_exp, 0); + b_nan = spu_andc(b_exp_1s, b_mant_0); + b_zero = spu_and (b_denorm0, b_mant_0); + b_inf = spu_and (b_exp_1s, b_mant_0); + b_denorm = spu_andc(b_denorm0, b_zero); + + /* Scale denorm inputs to into normalized numbers by conditionally scaling the + * input parameters. + */ + a = spu_sub(spu_or(a_in, exp_53), spu_sel(exp_53, a_in, sign_mask)); + a = spu_sel(a_in, a, a_denorm); + + b = spu_sub(spu_or(b_in, exp_53), spu_sel(exp_53, b_in, sign_mask)); + b = spu_sel(b_in, b, b_denorm); + + /* Extract the divisor and dividend exponent and force parameters into the signed + * range [1.0,2.0) or [-1.0,2.0). + */ + exp_a = spu_and((vec_ullong2)a, exp_mask); + exp_b = spu_and((vec_ullong2)b, exp_mask); + + mant_a = spu_sel(a, one, (vec_ullong2)exp_mask); + mant_b = spu_sel(b, one, (vec_ullong2)exp_mask); + + /* Approximate the single reciprocal of b by using + * the single precision reciprocal estimate followed by one + * single precision iteration of Newton-Raphson. + */ + mant_bf = spu_roundtf(mant_b); + inv_bf = spu_re(mant_bf); + inv_bf = spu_madd(spu_nmsub(mant_bf, inv_bf, onef), inv_bf, inv_bf); + + /* Perform 2 more Newton-Raphson iterations in double precision. The + * result (q1) is in the range (0.5, 2.0). + */ + inv_b = spu_extend(inv_bf); + inv_b = spu_madd(spu_nmsub(mant_b, inv_b, one), inv_b, inv_b); + q0 = spu_mul(mant_a, inv_b); + q1 = spu_madd(spu_nmsub(mant_b, q0, mant_a), inv_b, q0); + + /* Determine the exponent correction factor that must be applied + * to q1 by taking into account the exponent of the normalized inputs + * and the scale factors that were applied to normalize them. + */ + exp = spu_rlmaska(spu_sub((vec_int4)exp_a, (vec_int4)exp_b), -20); + exp = spu_add(exp, (vec_int4)spu_add(spu_and((vec_int4)a_denorm, -0x34), spu_and((vec_int4)b_denorm, 0x34))); + + /* Bias the quotient exponent depending on the sign of the exponent correction + * factor so that a single multiplier will ensure the entire double precision + * domain (including denorms) can be achieved. + * + * exp bias q1 adjust exp + * ===== ======== ========== + * positive 2^+65 -65 + * negative 2^-64 +64 + */ + exp_bias = spu_xor(spu_rlmaska(exp, -31), 64); + exp = spu_sub(exp, exp_bias); + + q1 = spu_sel(q1, (vec_double2)spu_add((vec_int4)q1, spu_sl(exp_bias, 20)), exp_mask); + + /* Compute a multiplier (mult) to applied to the quotient (q1) to produce the + * expected result. On overflow, clamp the multiplier to the maximum non-infinite + * number in case the rounding mode is not round-to-nearest. + */ + exp = spu_add(exp, 0x3FF); + no_underflow = spu_cmpgt(exp, 0); + overflow = spu_cmpgt(exp, 0x7FE); + exp = spu_and(spu_sl(exp, 20), (vec_int4)no_underflow); + exp = spu_and(exp, (vec_int4)exp_mask); + + mult = spu_sel((vec_double2)exp, (vec_double2)(spu_add((vec_uint4)exp_mask, -1)), (vec_ullong2)overflow); + + /* Handle special value conditions. These include: + * + * 1) IF either operand is a NaN OR both operands are 0 or INFINITY THEN a NaN + * results. + * 2) ELSE IF the dividend is an INFINITY OR the divisor is 0 THEN a INFINITY results. + * 3) ELSE IF the dividend is 0 OR the divisor is INFINITY THEN a 0 results. + */ + mult = spu_andc(mult, (vec_double2)spu_or(a_zero, b_inf)); + mult = spu_sel(mult, (vec_double2)exp_mask, spu_or(a_inf, b_zero)); + + nan = spu_or(a_nan, b_nan); + nan = spu_or(nan, spu_and(a_zero, b_zero)); + nan = spu_or(nan, spu_and(a_inf, b_inf)); + + mult = spu_or(mult, (vec_double2)nan); + + /* Scale the final quotient */ + + q2 = spu_mul(q1, mult); + + return (q2); +} + + +/* We use the same function for vector and scalar division. Provide the + scalar entry point as an alias. */ +double __divdf3 (double a, double b) + __attribute__ ((__alias__ ("__divv2df3"))); + +/* Some toolchain builds used the __fast_divdf3 name for this helper function. + Provide this as another alternate entry point for compatibility. */ +double __fast_divdf3 (double a, double b) + __attribute__ ((__alias__ ("__divv2df3"))); + |