Files
LithosAnanke/kernel/include/starkernel/q48_16.h
T
Claude 16b9747d33 chore(license): the source headers name the Starship License 1.0 (SL-1.0), as LICENSE does [skip ci]
347 headers said "Licensed under the StarForth License, Version 1.0" -- a
shortening (Captain Bob, 2026-11-08: "License file SL I think I shortened
accidently"); LICENSE is, and has been since the first commit, the
Starship License 1.0 (SL-1.0, SPDX LicenseRef-Starship-1.0). 349 files,
566 occurrences, now "Starship License, Version 1.0 (SL-1.0)".

Left as they are, pending a ruling: docs/patent/ (the patent figures),
docs/formal/ (the citable volumes) and the generated reports under
docs/working/experiments/ (32 files). Comments and license text only:
the amd64 kernel builds, every changed script parses.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GE3SDvQn5EoxdGufk84zz2
2026-11-08 17:54:24 +00:00

167 lines
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/*
StarForth — Steady-State Virtual Machine Runtime
Copyright (c) 2023–2025 Robert A. James
All rights reserved.
This file is part of the StarForth project.
Licensed under the Starship License, Version 1.0 (SL-1.0) (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at:
https://github.com/star.4th@proton.me/StarForth/LICENSE.txt
This software is provided "AS IS", WITHOUT WARRANTY OF ANY KIND,
express or implied, including but not limited to the warranties of
merchantability, fitness for a particular purpose, and noninfringement.
See the License for the specific language governing permissions and
limitations under the License.
StarForth — Steady-State Virtual Machine Runtime
Copyright (c) 2023–2025 Robert A. James
All rights reserved.
This file is part of the StarForth project.
Licensed under the Starship License, Version 1.0 (SL-1.0) (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at:
https://github.com/star.4th@proton.me/StarForth/LICENSE.txt
This software is provided "AS IS", WITHOUT WARRANTY OF ANY KIND,
express or implied, including but not limited to the warranties of
merchantability, fitness for a particular purpose, and noninfringement.
See the License for the specific language governing permissions and
limitations under the License.
*/
/**
* q48_16.h - Q48.16 Fixed-Point Arithmetic for StarKernel
*
* Format: uint64_t with fixed decimal point after bit 15
* - Bits 0-15: Fractional part (1/65536 resolution)
* - Bits 16-63: Integer part (up to 2^48-1)
*
* Example: 0x00010000 = 1.0, 0x00018000 = 1.5
*
* All operations are integer-only. NO FLOATING-POINT.
*/
#ifndef STARKERNEL_Q48_16_H
#define STARKERNEL_Q48_16_H
/* If the hosted-VM q48_16.h is already pulled in (e.g. via inference_engine.h),
* skip the duplicate static-inline definitions — clang rejects them as errors. */
#ifndef Q48_16_H
#include <stdint.h>
typedef uint64_t q48_16_t;
/* Q48.16 representation of 1.0 */
#define Q48_ONE ((q48_16_t)0x10000ULL)
/* ============================================================================
* Core Arithmetic Operations
* ============================================================================ */
/*
* Multiply two Q48.16 values: (a * b) >> 16
*/
q48_16_t q48_mul(q48_16_t a, q48_16_t b);
/*
* Divide two Q48.16 values: (a << 16) / b
* Returns 0 if b == 0.
*/
q48_16_t q48_div(q48_16_t a, q48_16_t b);
/**
* Add two Q48.16 values
*/
static inline q48_16_t q48_add(q48_16_t a, q48_16_t b) {
return a + b;
}
/**
* Subtract two Q48.16 values
*/
static inline q48_16_t q48_sub(q48_16_t a, q48_16_t b) {
return a - b;
}
/**
* Absolute value of Q48.16 (treats as unsigned, so just returns a)
*/
static inline q48_16_t q48_abs(q48_16_t a) {
return a; /* Q48.16 is unsigned; for signed use, caller handles */
}
/* ============================================================================
* Conversion Operations
* ============================================================================ */
/**
* Convert unsigned 64-bit integer to Q48.16: u << 16
*/
static inline q48_16_t q48_from_u64(uint64_t u) {
return u << 16;
}
/**
* Convert Q48.16 to a 64-bit integer (truncate fractional): q >> 16,
* arithmetic (signed) shift so negative q sign-extends correctly instead
* of producing garbage from an unsigned logical shift. Bit-identical to
* the old behavior for non-negative q.
*/
static inline uint64_t q48_to_u64(q48_16_t q) {
return (uint64_t)(((int64_t)q) >> 16);
}
/* ============================================================================
* Approximation Operations (Integer-Only)
* ============================================================================ */
/*
* Approximate natural logarithm in Q48.16 (integer-only)
* Input: x in Q48.16 format (x > 0)
* Output: ln(x) in Q48.16 format
*/
q48_16_t q48_log_approx(q48_16_t x);
/*
* Approximate exponential e^x in Q48.16 (integer-only)
* Input: q in Q48.16 format
* Output: e^q in Q48.16 format
*/
q48_16_t q48_exp_approx(q48_16_t q);
/*
* Approximate square root in Q48.16 (integer-only, Newton-Raphson)
* Input: q in Q48.16 format
* Output: sqrt(q) in Q48.16 format
*/
q48_16_t q48_sqrt_approx(q48_16_t q);
/*
* Approximate sin(q) in Q48.16 (integer-only, Taylor series, radians)
* Input: q in Q48.16 format (any magnitude)
* Output: sin(q) in Q48.16 format
*/
q48_16_t q48_sin_approx(q48_16_t q);
/*
* Approximate cos(q) in Q48.16 (integer-only, Taylor series, radians)
* Input: q in Q48.16 format (any magnitude)
* Output: cos(q) in Q48.16 format
*/
q48_16_t q48_cos_approx(q48_16_t q);
#endif /* !Q48_16_H */
#endif /* STARKERNEL_Q48_16_H */