xref: /freebsd/contrib/llvm-project/compiler-rt/lib/builtins/int_lib.h (revision dd6565b7a60d228f021190a538caeb652275dc5c)

//===-- int_lib.h - configuration header for compiler-rt  -----------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file is a configuration header for compiler-rt.
// This file is not part of the interface of this library.
//
//===----------------------------------------------------------------------===//

#ifndef INT_LIB_H
#define INT_LIB_H

// Assumption: Signed integral is 2's complement.
// Assumption: Right shift of signed negative is arithmetic shift.
// Assumption: Endianness is little or big (not mixed).

// ABI macro definitions

#if __ARM_EABI__
#if defined(COMPILER_RT_ARMHF_TARGET) || (!defined(__clang__) && \
    defined(__GNUC__) && (__GNUC__ < 4 || __GNUC__ == 4 && __GNUC_MINOR__ < 5))
// The pcs attribute was introduced in GCC 4.5.0
#define COMPILER_RT_ABI
#else
#define COMPILER_RT_ABI __attribute__((__pcs__("aapcs")))
#endif
#else
#define COMPILER_RT_ABI
#endif

#define AEABI_RTABI __attribute__((__pcs__("aapcs")))

#if defined(_MSC_VER) && !defined(__clang__)
#define ALWAYS_INLINE __forceinline
#define NOINLINE __declspec(noinline)
#define NORETURN __declspec(noreturn)
#define UNUSED
#else
#define ALWAYS_INLINE __attribute__((always_inline))
#define NOINLINE __attribute__((noinline))
#define NORETURN __attribute__((noreturn))
#define UNUSED __attribute__((unused))
#endif

#define STR(a) #a
#define XSTR(a) STR(a)
#define SYMBOL_NAME(name) XSTR(__USER_LABEL_PREFIX__) #name

#if defined(__ELF__) || defined(__MINGW32__) || defined(__wasm__) ||           \
    defined(_AIX)
#define COMPILER_RT_ALIAS(name, aliasname) \
  COMPILER_RT_ABI __typeof(name) aliasname __attribute__((__alias__(#name)));
#elif defined(__APPLE__)
#if defined(VISIBILITY_HIDDEN)
#define COMPILER_RT_ALIAS_VISIBILITY(name) \
  __asm__(".private_extern " SYMBOL_NAME(name));
#else
#define COMPILER_RT_ALIAS_VISIBILITY(name)
#endif
#define COMPILER_RT_ALIAS(name, aliasname) \
  __asm__(".globl " SYMBOL_NAME(aliasname)); \
  COMPILER_RT_ALIAS_VISIBILITY(aliasname) \
  __asm__(SYMBOL_NAME(aliasname) " = " SYMBOL_NAME(name)); \
  COMPILER_RT_ABI __typeof(name) aliasname;
#elif defined(_WIN32)
#define COMPILER_RT_ALIAS(name, aliasname)
#else
#error Unsupported target
#endif

#if (defined(__FreeBSD__) || defined(__NetBSD__)) && (defined(_KERNEL) || defined(_STANDALONE))
//
// Kernel and boot environment can't use normal headers,
// so use the equivalent system headers.
//
#ifdef __FreeBSD__
#include <sys/limits.h>
#else
#include <machine/limits.h>
#endif
#include <sys/stdint.h>
#include <sys/types.h>
#else
// Include the standard compiler builtin headers we use functionality from.
#include <float.h>
#include <limits.h>
#include <stdbool.h>
#include <stdint.h>
#endif

// Include the commonly used internal type definitions.
#include "int_types.h"

// Include internal utility function declarations.
#include "int_util.h"

/*
 * Workaround for LLVM bug 11663.  Prevent endless recursion in
 * __c?zdi2(), where calls to __builtin_c?z() are expanded to
 * __c?zdi2() instead of __c?zsi2().
 *
 * Instead of placing this workaround in c?zdi2.c, put it in this
 * global header to prevent other C files from making the detour
 * through __c?zdi2() as well.
 *
 * This problem has been observed on FreeBSD for sparc64 and
 * mips64 with GCC 4.2.1, and for riscv with GCC 5.2.0.
 * Presumably it's any version of GCC, and targeting an arch that
 * does not have dedicated bit counting instructions.
 */
#if defined(__FreeBSD__) && (defined(__sparc64__) || \
    defined(__mips_n32) || defined(__mips_n64) || defined(__mips_o64) || \
    defined(__riscv))
si_int __clzsi2(si_int);
si_int __ctzsi2(si_int);
#define	__builtin_clz __clzsi2
#define	__builtin_ctz __ctzsi2
#endif /* FreeBSD && (sparc64 || mips_n32 || mips_n64 || mips_o64 || riscv) */

COMPILER_RT_ABI int __paritysi2(si_int a);
COMPILER_RT_ABI int __paritydi2(di_int a);

COMPILER_RT_ABI di_int __divdi3(di_int a, di_int b);
COMPILER_RT_ABI si_int __divsi3(si_int a, si_int b);
COMPILER_RT_ABI su_int __udivsi3(su_int n, su_int d);

COMPILER_RT_ABI su_int __udivmodsi4(su_int a, su_int b, su_int *rem);
COMPILER_RT_ABI du_int __udivmoddi4(du_int a, du_int b, du_int *rem);
#ifdef CRT_HAS_128BIT
COMPILER_RT_ABI int __clzti2(ti_int a);
COMPILER_RT_ABI tu_int __udivmodti4(tu_int a, tu_int b, tu_int *rem);
#endif

// Definitions for builtins unavailable on MSVC
#if defined(_MSC_VER) && !defined(__clang__)
#include <intrin.h>

int __inline __builtin_ctz(uint32_t value) {
  unsigned long trailing_zero = 0;
  if (_BitScanForward(&trailing_zero, value))
    return trailing_zero;
  return 32;
}

int __inline __builtin_clz(uint32_t value) {
  unsigned long leading_zero = 0;
  if (_BitScanReverse(&leading_zero, value))
    return 31 - leading_zero;
  return 32;
}

#if defined(_M_ARM) || defined(_M_X64)
int __inline __builtin_clzll(uint64_t value) {
  unsigned long leading_zero = 0;
  if (_BitScanReverse64(&leading_zero, value))
    return 63 - leading_zero;
  return 64;
}
#else
int __inline __builtin_clzll(uint64_t value) {
  if (value == 0)
    return 64;
  uint32_t msh = (uint32_t)(value >> 32);
  uint32_t lsh = (uint32_t)(value & 0xFFFFFFFF);
  if (msh != 0)
    return __builtin_clz(msh);
  return 32 + __builtin_clz(lsh);
}
#endif

#define __builtin_clzl __builtin_clzll
#endif // defined(_MSC_VER) && !defined(__clang__)

#endif // INT_LIB_H