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Make quality improvements
- Write some more unit tests - memcpy() on ARM is now faster - Address the Musl complex math FIXME comments - Some libm funcs like pow() now support setting errno - Import the latest and greatest math functions from ARM - Use more accurate atan2f() and log1pf() implementations - atoi() and atol() will no longer saturate or clobber errno
This commit is contained in:
Justine Tunney
parent
af8f2bd19f
commit
592f6ebc20
122 changed files with 6305 additions and 3859 deletions
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@ -1,9 +1,9 @@
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/*-*- mode:c;indent-tabs-mode:t;c-basic-offset:8;tab-width:8;coding:utf-8 -*-│
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│ vi: set noet ft=c ts=8 sw=8 fenc=utf-8 :vi │
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/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
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│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi │
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╚──────────────────────────────────────────────────────────────────────────────╝
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│ │
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│ Optimized Routines │
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│ Copyright (c) 1999-2022, Arm Limited. │
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│ Copyright (c) 2018-2024, Arm Limited. │
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│ │
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│ Permission is hereby granted, free of charge, to any person obtaining │
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│ a copy of this software and associated documentation files (the │
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@ -25,20 +25,9 @@
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│ SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. │
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│ │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "libc/intrin/likely.h"
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#include "libc/math.h"
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#include "libc/tinymath/complex.internal.h"
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#include "libc/tinymath/internal.h"
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#include "libc/tinymath/log2f_data.internal.h"
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#include "libc/tinymath/arm.internal.h"
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__static_yoink("arm_optimized_routines_notice");
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/*
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* Single-precision log2 function.
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*
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* Copyright (c) 2017-2018, Arm Limited.
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* SPDX-License-Identifier: MIT
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*/
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/*
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LOG2F_TABLE_BITS = 4
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LOG2F_POLY_ORDER = 4
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@ -53,52 +42,65 @@ Relative error: 1.9 * 2^-26 (before rounding.)
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#define OFF 0x3f330000
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/**
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* Calculates log₂𝑥.
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* Returns base-2 logarithm of x.
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*
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* - ULP error: 0.752 (nearest rounding.)
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* - Relative error: 1.9 * 2^-26 (before rounding.)
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*/
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float log2f(float x)
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float
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log2f (float x)
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{
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double_t z, r, r2, p, y, y0, invc, logc;
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uint32_t ix, iz, top, tmp;
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int k, i;
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/* double_t for better performance on targets with FLT_EVAL_METHOD==2. */
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double_t z, r, r2, p, y, y0, invc, logc;
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uint32_t ix, iz, top, tmp;
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int k, i;
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ix = asuint(x);
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/* Fix sign of zero with downward rounding when x==1. */
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if (WANT_ROUNDING && UNLIKELY(ix == 0x3f800000))
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return 0;
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if (UNLIKELY(ix - 0x00800000 >= 0x7f800000 - 0x00800000)) {
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/* x < 0x1p-126 or inf or nan. */
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if (ix * 2 == 0)
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return __math_divzerof(1);
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if (ix == 0x7f800000) /* log2(inf) == inf. */
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return x;
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if ((ix & 0x80000000) || ix * 2 >= 0xff000000)
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return __math_invalidf(x);
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/* x is subnormal, normalize it. */
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ix = asuint(x * 0x1p23f);
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ix -= 23 << 23;
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}
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ix = asuint (x);
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#if WANT_ROUNDING
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/* Fix sign of zero with downward rounding when x==1. */
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if (unlikely (ix == 0x3f800000))
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return 0;
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#endif
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if (unlikely (ix - 0x00800000 >= 0x7f800000 - 0x00800000))
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{
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/* x < 0x1p-126 or inf or nan. */
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if (ix * 2 == 0)
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return __math_divzerof (1);
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if (ix == 0x7f800000) /* log2(inf) == inf. */
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return x;
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if ((ix & 0x80000000) || ix * 2 >= 0xff000000)
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return __math_invalidf (x);
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/* x is subnormal, normalize it. */
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ix = asuint (x * 0x1p23f);
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ix -= 23 << 23;
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}
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/* x = 2^k z; where z is in range [OFF,2*OFF] and exact.
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The range is split into N subintervals.
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The ith subinterval contains z and c is near its center. */
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tmp = ix - OFF;
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i = (tmp >> (23 - LOG2F_TABLE_BITS)) % N;
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top = tmp & 0xff800000;
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iz = ix - top;
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k = (int32_t)tmp >> 23; /* arithmetic shift */
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invc = T[i].invc;
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logc = T[i].logc;
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z = (double_t)asfloat(iz);
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/* x = 2^k z; where z is in range [OFF,2*OFF] and exact.
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The range is split into N subintervals.
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The ith subinterval contains z and c is near its center. */
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tmp = ix - OFF;
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i = (tmp >> (23 - LOG2F_TABLE_BITS)) % N;
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top = tmp & 0xff800000;
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iz = ix - top;
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k = (int32_t) tmp >> 23; /* arithmetic shift */
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invc = T[i].invc;
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logc = T[i].logc;
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z = (double_t) asfloat (iz);
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/* log2(x) = log1p(z/c-1)/ln2 + log2(c) + k */
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r = z * invc - 1;
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y0 = logc + (double_t)k;
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/* log2(x) = log1p(z/c-1)/ln2 + log2(c) + k */
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r = z * invc - 1;
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y0 = logc + (double_t) k;
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/* Pipelined polynomial evaluation to approximate log1p(r)/ln2. */
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r2 = r * r;
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y = A[1] * r + A[2];
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y = A[0] * r2 + y;
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p = A[3] * r + y0;
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y = y * r2 + p;
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return eval_as_float(y);
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/* Pipelined polynomial evaluation to approximate log1p(r)/ln2. */
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r2 = r * r;
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y = A[1] * r + A[2];
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y = A[0] * r2 + y;
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p = A[3] * r + y0;
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y = y * r2 + p;
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return eval_as_float (y);
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}
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#if USE_GLIBC_ABI
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strong_alias (log2f, __log2f_finite)
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hidden_alias (log2f, __ieee754_log2f)
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#endif
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