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Diffstat (limited to 'src/vppinfra/clib.h')
| -rw-r--r-- | src/vppinfra/clib.h | 359 |
1 files changed, 359 insertions, 0 deletions
diff --git a/src/vppinfra/clib.h b/src/vppinfra/clib.h new file mode 100644 index 00000000000..0386c756833 --- /dev/null +++ b/src/vppinfra/clib.h @@ -0,0 +1,359 @@ +/* + * Copyright (c) 2015 Cisco and/or its affiliates. + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at: + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +/* + Copyright (c) 2001, 2002, 2003 Eliot Dresselhaus + + Permission is hereby granted, free of charge, to any person obtaining + a copy of this software and associated documentation files (the + "Software"), to deal in the Software without restriction, including + without limitation the rights to use, copy, modify, merge, publish, + distribute, sublicense, and/or sell copies of the Software, and to + permit persons to whom the Software is furnished to do so, subject to + the following conditions: + + The above copyright notice and this permission notice shall be + included in all copies or substantial portions of the Software. + + THE 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. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE + LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION + OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION + WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. +*/ + +#ifndef included_clib_h +#define included_clib_h + +/* Standalone means to not assume we are running on a Unix box. */ +#if ! defined (CLIB_STANDALONE) && ! defined (CLIB_LINUX_KERNEL) +#define CLIB_UNIX +#endif + +#include <vppinfra/types.h> + +/* Global DEBUG flag. Setting this to 1 or 0 turns off + ASSERT (see vppinfra/error.h) & other debugging code. */ +#ifndef CLIB_DEBUG +#define CLIB_DEBUG 0 +#endif + +#ifndef NULL +#define NULL ((void *) 0) +#endif + +#define BITS(x) (8*sizeof(x)) +#define ARRAY_LEN(x) (sizeof (x)/sizeof (x[0])) + +#define _STRUCT_FIELD(t,f) (((t *) 0)->f) +#define STRUCT_OFFSET_OF(t,f) ((uword) & _STRUCT_FIELD (t, f)) +#define STRUCT_BIT_OFFSET_OF(t,f) (BITS(u8) * (uword) & _STRUCT_FIELD (t, f)) +#define STRUCT_SIZE_OF(t,f) (sizeof (_STRUCT_FIELD (t, f))) +#define STRUCT_BITS_OF(t,f) (BITS (_STRUCT_FIELD (t, f))) +#define STRUCT_ARRAY_LEN(t,f) ARRAY_LEN (_STRUCT_FIELD (t, f)) +#define STRUCT_MARK(mark) u8 mark[0] +#define STRUCT_MARK_PTR(v, f) &(v)->f + +/* Stride in bytes between struct array elements. */ +#define STRUCT_STRIDE_OF(t,f) \ + ( ((uword) & (((t *) 0)[1].f)) \ + - ((uword) & (((t *) 0)[0].f))) + +#define STRUCT_OFFSET_OF_VAR(v,f) ((uword) (&(v)->f) - (uword) (v)) + +/* Used to pack structure elements. */ +#define CLIB_PACKED(x) x __attribute__ ((packed)) +#define CLIB_UNUSED(x) x __attribute__ ((unused)) + +#define never_inline __attribute__ ((__noinline__)) + +#if CLIB_DEBUG > 0 +#define always_inline static inline +#define static_always_inline static inline +#else +#define always_inline static inline __attribute__ ((__always_inline__)) +#define static_always_inline static inline __attribute__ ((__always_inline__)) +#endif + + +/* Reserved (unused) structure element with address offset between + from and to. */ +#define CLIB_PAD_FROM_TO(from,to) u8 pad_##from[(to) - (from)] + +/* Hints to compiler about hot/cold code. */ +#define PREDICT_FALSE(x) __builtin_expect((x),0) +#define PREDICT_TRUE(x) __builtin_expect((x),1) + +/* Full memory barrier (read and write). */ +#define CLIB_MEMORY_BARRIER() __sync_synchronize () + +/* Arranges for function to be called before main. */ +#define INIT_FUNCTION(decl) \ + decl __attribute ((constructor)); \ + decl + +/* Arranges for function to be called before exit. */ +#define EXIT_FUNCTION(decl) \ + decl __attribute ((destructor)); \ + decl + +/* Use __builtin_clz if available. */ +#ifdef __GNUC__ +#include <features.h> +#if __GNUC_PREREQ(3, 4) +#if uword_bits == 64 +#define count_leading_zeros(count,x) count = __builtin_clzll (x) +#define count_trailing_zeros(count,x) count = __builtin_ctzll (x) +#else +#define count_leading_zeros(count,x) count = __builtin_clzl (x) +#define count_trailing_zeros(count,x) count = __builtin_ctzl (x) +#endif +#endif +#endif + +#ifndef count_leading_zeros + +/* Misc. integer arithmetic functions. */ +#if defined (i386) +#define count_leading_zeros(count, x) \ + do { \ + word _clz; \ + __asm__ ("bsrl %1,%0" \ + : "=r" (_clz) : "rm" ((word) (x)));\ + (count) = _clz ^ 31; \ + } while (0) + +#define count_trailing_zeros(count, x) \ + __asm__ ("bsfl %1,%0" : "=r" (count) : "rm" ((word)(x))) +#endif /* i386 */ + +#if defined (__alpha__) && defined (HAVE_CIX) +#define count_leading_zeros(count, x) \ + __asm__ ("ctlz %1,%0" \ + : "=r" ((word) (count)) \ + : "r" ((word) (x))) +#define count_trailing_zeros(count, x) \ + __asm__ ("cttz %1,%0" \ + : "=r" ((word) (count)) \ + : "r" ((word) (x))) +#endif /* alpha && HAVE_CIX */ + +#if __mips >= 4 + +/* Select between 32/64 opcodes. */ +#if uword_bits == 32 +#define count_leading_zeros(_count, _x) \ + __asm__ ("clz %[count],%[x]" \ + : [count] "=r" ((word) (_count)) \ + : [x] "r" ((word) (_x))) +#else +#define count_leading_zeros(_count, _x) \ + __asm__ ("dclz %[count],%[x]" \ + : [count] "=r" ((word) (_count)) \ + : [x] "r" ((word) (_x))) +#endif + +#endif /* __mips >= 4 */ + +#endif /* count_leading_zeros */ + +#if defined (count_leading_zeros) +always_inline uword +min_log2 (uword x) +{ + uword n; + count_leading_zeros (n, x); + return BITS (uword) - n - 1; +} +#else +always_inline uword +min_log2 (uword x) +{ + uword a = x, b = BITS (uword) / 2, c = 0, r = 0; + + /* Reduce x to 4 bit result. */ +#define _ \ +{ \ + c = a >> b; \ + if (c) a = c; \ + if (c) r += b; \ + b /= 2; \ +} + + if (BITS (uword) > 32) + _; + _; + _; + _; +#undef _ + + /* Do table lookup on 4 bit partial. */ + if (BITS (uword) > 32) + { + const u64 table = 0x3333333322221104LL; + uword t = (table >> (4 * a)) & 0xf; + r = t < 4 ? r + t : ~0; + } + else + { + const u32 table = 0x22221104; + uword t = (a & 8) ? 3 : ((table >> (4 * a)) & 0xf); + r = t < 4 ? r + t : ~0; + } + + return r; +} +#endif + +always_inline uword +max_log2 (uword x) +{ + uword l = min_log2 (x); + if (x > ((uword) 1 << l)) + l++; + return l; +} + +always_inline u64 +min_log2_u64 (u64 x) +{ + if (BITS (uword) == 64) + return min_log2 (x); + else + { + uword l, y; + y = x; + l = 0; + if (y == 0) + { + l += 32; + x >>= 32; + } + l += min_log2 (x); + return l; + } +} + +always_inline uword +pow2_mask (uword x) +{ + return ((uword) 1 << x) - (uword) 1; +} + +always_inline uword +max_pow2 (uword x) +{ + word y = (word) 1 << min_log2 (x); + if (x > y) + y *= 2; + return y; +} + +always_inline uword +is_pow2 (uword x) +{ + return 0 == (x & (x - 1)); +} + +always_inline uword +round_pow2 (uword x, uword pow2) +{ + return (x + pow2 - 1) & ~(pow2 - 1); +} + +always_inline u64 +round_pow2_u64 (u64 x, u64 pow2) +{ + return (x + pow2 - 1) & ~(pow2 - 1); +} + +always_inline uword +first_set (uword x) +{ + return x & -x; +} + +always_inline uword +log2_first_set (uword x) +{ + uword result; +#ifdef count_trailing_zeros + count_trailing_zeros (result, x); +#else + result = min_log2 (first_set (x)); +#endif + return result; +} + +always_inline f64 +flt_round_down (f64 x) +{ + return (int) x; +} + +always_inline word +flt_round_nearest (f64 x) +{ + return (word) (x + .5); +} + +always_inline f64 +flt_round_to_multiple (f64 x, f64 f) +{ + return f * flt_round_nearest (x / f); +} + +#define clib_max(x,y) \ +({ \ + __typeof__ (x) _x = (x); \ + __typeof__ (y) _y = (y); \ + _x > _y ? _x : _y; \ +}) + +#define clib_min(x,y) \ +({ \ + __typeof__ (x) _x = (x); \ + __typeof__ (y) _y = (y); \ + _x < _y ? _x : _y; \ +}) + +#define clib_abs(x) \ +({ \ + __typeof__ (x) _x = (x); \ + _x < 0 ? -_x : _x; \ +}) + +/* Standard standalone-only function declarations. */ +#ifndef CLIB_UNIX +void clib_standalone_init (void *memory, uword memory_bytes); + +void qsort (void *base, uword n, uword size, + int (*)(const void *, const void *)); +#endif + +/* Stack backtrace. */ +uword +clib_backtrace (uword * callers, uword max_callers, uword n_frames_to_skip); + +#endif /* included_clib_h */ + +/* + * fd.io coding-style-patch-verification: ON + * + * Local Variables: + * eval: (c-set-style "gnu") + * End: + */ |