1 /* The MIT License 2 3 Copyright (C) 2020 Genome Research Ltd. 4 5 Permission is hereby granted, free of charge, to any person obtaining 6 a copy of this software and associated documentation files (the 7 "Software"), to deal in the Software without restriction, including 8 without limitation the rights to use, copy, modify, merge, publish, 9 distribute, sublicense, and/or sell copies of the Software, and to 10 permit persons to whom the Software is furnished to do so, subject to 11 the following conditions: 12 13 The above copyright notice and this permission notice shall be 14 included in all copies or substantial portions of the Software. 15 16 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 17 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 18 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 19 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS 20 BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN 21 ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 22 CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 23 SOFTWARE. 24 */ 25 module htslib.kroundup; 26 27 @system: 28 nothrow: 29 @nogc: 30 31 /// round 32 or 64 bit (u)int x to power of 2 that is equal or greater (JSB) 32 /// new impl based on 33 /// #define kroundup64(x) ((x) > 0 ? \ 34 // (--(x), \ 35 // (x)|=(x)>>(sizeof(x)/8), \ 36 // (x)|=(x)>>(sizeof(x)/4), \ 37 // (x)|=(x)>>(sizeof(x)/2), \ 38 // (x)|=(x)>>(sizeof(x)), \ 39 // (x)|=(x)>>(sizeof(x)*2), \ 40 // (x)|=(x)>>(sizeof(x)*4), \ 41 // (x) += !k_high_bit_set(x), \ 42 // (x)) \ 43 // : 0) 44 pragma(inline, true) 45 extern (D) 46 void kroundup_size_t(T)(ref T x) { 47 if(x > 0){ 48 x -= 1; 49 x |= (x >> (T.sizeof/8)); 50 x |= (x >> (T.sizeof/4)); 51 x |= (x >> (T.sizeof/2)); 52 x |= (x >> (T.sizeof)); 53 x |= (x >> (T.sizeof*2)); 54 x |= (x >> (T.sizeof*4)); 55 x += !k_high_bit_set(x); 56 }else{ 57 x = 0; 58 } 59 } 60 61 extern (C): 62 63 // Value of this macro is 1 if x is a signed type; 0 if unsigned 64 extern (D) auto k_signed_type(T)(auto ref T x) 65 { 66 return !(-(x * 0 + 1) > 0); 67 } 68 69 /* 70 Macro with value 1 if the highest bit in x is set for any integer type 71 72 This is written avoiding conditionals (?: operator) to reduce the likelihood 73 of gcc attempting jump thread optimisations for code paths where (x) is 74 large. These optimisations can cause gcc to issue warnings about excessively 75 large memory allocations when the kroundup64() macro below is used with 76 malloc(). Such warnings can be misleading as they imply only the large 77 allocation happens when it's actually working fine for normal values of (x). 78 79 See https://developers.redhat.com/blog/2019/03/13/understanding-gcc-warnings-part-2/ 80 */ 81 extern (D) auto k_high_bit_set(T)(auto ref T x) 82 { 83 return ((x >> (x.sizeof * 8 - 1 - k_signed_type(x))) & 1); 84 } 85 86 /*! @hideinitializer 87 @abstract Round up to next power of two 88 @discussion 89 This macro will work for unsigned types up to uint64_t. 90 91 If the next power of two does not fit in the given type, it will set 92 the largest value that does. 93 */ 94 95 // Historic interfaces for 32-bit and size_t values. The macro above 96 // works for both (as long as size_t is no more than 64 bits). 97 98 void kroundup64(T)(ref T x) {kroundup_size_t!T(x);} 99 void kroundup32(T)(ref T x) {kroundup_size_t!T(x);} 100 101