diff options
Diffstat (limited to 'pl/math/sv_log_2u5.c')
-rw-r--r-- | pl/math/sv_log_2u5.c | 76 |
1 files changed, 0 insertions, 76 deletions
diff --git a/pl/math/sv_log_2u5.c b/pl/math/sv_log_2u5.c deleted file mode 100644 index 2530c9e3f62c..000000000000 --- a/pl/math/sv_log_2u5.c +++ /dev/null @@ -1,76 +0,0 @@ -/* - * Double-precision SVE log(x) function. - * - * Copyright (c) 2020-2023, Arm Limited. - * SPDX-License-Identifier: MIT OR Apache-2.0 WITH LLVM-exception - */ - -#include "sv_math.h" -#include "pl_sig.h" -#include "pl_test.h" - -#define P(i) sv_f64 (__v_log_data.poly[i]) -#define N (1 << V_LOG_TABLE_BITS) -#define Off (0x3fe6900900000000) -#define MaxTop (0x7ff) -#define MinTop (0x001) -#define ThreshTop (0x7fe) /* MaxTop - MinTop. */ - -static svfloat64_t NOINLINE -special_case (svfloat64_t x, svfloat64_t y, svbool_t cmp) -{ - return sv_call_f64 (log, x, y, cmp); -} - -/* SVE port of AdvSIMD log algorithm. - Maximum measured error is 2.17 ulp: - SV_NAME_D1 (log)(0x1.a6129884398a3p+0) got 0x1.ffffff1cca043p-2 - want 0x1.ffffff1cca045p-2. */ -svfloat64_t SV_NAME_D1 (log) (svfloat64_t x, const svbool_t pg) -{ - svuint64_t ix = svreinterpret_u64 (x); - svuint64_t top = svlsr_x (pg, ix, 52); - svbool_t cmp = svcmpge (pg, svsub_x (pg, top, MinTop), sv_u64 (ThreshTop)); - - /* x = 2^k z; where z is in range [Off,2*Off) and exact. - The range is split into N subintervals. - The ith subinterval contains z and c is near its center. */ - svuint64_t tmp = svsub_x (pg, ix, Off); - /* Calculate table index = (tmp >> (52 - V_LOG_TABLE_BITS)) % N. - The actual value of i is double this due to table layout. */ - svuint64_t i - = svand_x (pg, svlsr_x (pg, tmp, (51 - V_LOG_TABLE_BITS)), (N - 1) << 1); - svint64_t k - = svasr_x (pg, svreinterpret_s64 (tmp), 52); /* Arithmetic shift. */ - svuint64_t iz = svsub_x (pg, ix, svand_x (pg, tmp, 0xfffULL << 52)); - svfloat64_t z = svreinterpret_f64 (iz); - /* Lookup in 2 global lists (length N). */ - svfloat64_t invc = svld1_gather_index (pg, &__v_log_data.table[0].invc, i); - svfloat64_t logc = svld1_gather_index (pg, &__v_log_data.table[0].logc, i); - - /* log(x) = log1p(z/c-1) + log(c) + k*Ln2. */ - svfloat64_t r = svmad_x (pg, invc, z, -1); - svfloat64_t kd = svcvt_f64_x (pg, k); - /* hi = r + log(c) + k*Ln2. */ - svfloat64_t hi = svmla_x (pg, svadd_x (pg, logc, r), kd, __v_log_data.ln2); - /* y = r2*(A0 + r*A1 + r2*(A2 + r*A3 + r2*A4)) + hi. */ - svfloat64_t r2 = svmul_x (pg, r, r); - svfloat64_t y = svmla_x (pg, P (2), r, P (3)); - svfloat64_t p = svmla_x (pg, P (0), r, P (1)); - y = svmla_x (pg, y, r2, P (4)); - y = svmla_x (pg, p, r2, y); - - if (unlikely (svptest_any (pg, cmp))) - return special_case (x, svmla_x (svnot_z (pg, cmp), hi, r2, y), cmp); - return svmla_x (pg, hi, r2, y); -} - -PL_SIG (SV, D, 1, log, 0.01, 11.1) -PL_TEST_ULP (SV_NAME_D1 (log), 1.68) -PL_TEST_INTERVAL (SV_NAME_D1 (log), -0.0, -inf, 1000) -PL_TEST_INTERVAL (SV_NAME_D1 (log), 0, 0x1p-149, 1000) -PL_TEST_INTERVAL (SV_NAME_D1 (log), 0x1p-149, 0x1p-126, 4000) -PL_TEST_INTERVAL (SV_NAME_D1 (log), 0x1p-126, 0x1p-23, 50000) -PL_TEST_INTERVAL (SV_NAME_D1 (log), 0x1p-23, 1.0, 50000) -PL_TEST_INTERVAL (SV_NAME_D1 (log), 1.0, 100, 50000) -PL_TEST_INTERVAL (SV_NAME_D1 (log), 100, inf, 50000) |