1*0a6a1f1dSLionel Sambuc /* ===-- popcountti2.c - Implement __popcountti2 ----------------------------=== 2*0a6a1f1dSLionel Sambuc * 3*0a6a1f1dSLionel Sambuc * The LLVM Compiler Infrastructure 4*0a6a1f1dSLionel Sambuc * 5*0a6a1f1dSLionel Sambuc * This file is dual licensed under the MIT and the University of Illinois Open 6*0a6a1f1dSLionel Sambuc * Source Licenses. See LICENSE.TXT for details. 7*0a6a1f1dSLionel Sambuc * 8*0a6a1f1dSLionel Sambuc * ===----------------------------------------------------------------------=== 9*0a6a1f1dSLionel Sambuc * 10*0a6a1f1dSLionel Sambuc * This file implements __popcountti2 for the compiler_rt library. 11*0a6a1f1dSLionel Sambuc * 12*0a6a1f1dSLionel Sambuc * ===----------------------------------------------------------------------=== 13*0a6a1f1dSLionel Sambuc */ 14*0a6a1f1dSLionel Sambuc 15*0a6a1f1dSLionel Sambuc #include "int_lib.h" 16*0a6a1f1dSLionel Sambuc 17*0a6a1f1dSLionel Sambuc #ifdef CRT_HAS_128BIT 18*0a6a1f1dSLionel Sambuc 19*0a6a1f1dSLionel Sambuc /* Returns: count of 1 bits */ 20*0a6a1f1dSLionel Sambuc 21*0a6a1f1dSLionel Sambuc COMPILER_RT_ABI si_int __popcountti2(ti_int a)22*0a6a1f1dSLionel Sambuc__popcountti2(ti_int a) 23*0a6a1f1dSLionel Sambuc { 24*0a6a1f1dSLionel Sambuc tu_int x3 = (tu_int)a; 25*0a6a1f1dSLionel Sambuc x3 = x3 - ((x3 >> 1) & (((tu_int)0x5555555555555555uLL << 64) | 26*0a6a1f1dSLionel Sambuc 0x5555555555555555uLL)); 27*0a6a1f1dSLionel Sambuc /* Every 2 bits holds the sum of every pair of bits (64) */ 28*0a6a1f1dSLionel Sambuc x3 = ((x3 >> 2) & (((tu_int)0x3333333333333333uLL << 64) | 0x3333333333333333uLL)) 29*0a6a1f1dSLionel Sambuc + (x3 & (((tu_int)0x3333333333333333uLL << 64) | 0x3333333333333333uLL)); 30*0a6a1f1dSLionel Sambuc /* Every 4 bits holds the sum of every 4-set of bits (3 significant bits) (32) */ 31*0a6a1f1dSLionel Sambuc x3 = (x3 + (x3 >> 4)) 32*0a6a1f1dSLionel Sambuc & (((tu_int)0x0F0F0F0F0F0F0F0FuLL << 64) | 0x0F0F0F0F0F0F0F0FuLL); 33*0a6a1f1dSLionel Sambuc /* Every 8 bits holds the sum of every 8-set of bits (4 significant bits) (16) */ 34*0a6a1f1dSLionel Sambuc du_int x2 = (du_int)(x3 + (x3 >> 64)); 35*0a6a1f1dSLionel Sambuc /* Every 8 bits holds the sum of every 8-set of bits (5 significant bits) (8) */ 36*0a6a1f1dSLionel Sambuc su_int x = (su_int)(x2 + (x2 >> 32)); 37*0a6a1f1dSLionel Sambuc /* Every 8 bits holds the sum of every 8-set of bits (6 significant bits) (4) */ 38*0a6a1f1dSLionel Sambuc x = x + (x >> 16); 39*0a6a1f1dSLionel Sambuc /* Every 8 bits holds the sum of every 8-set of bits (7 significant bits) (2) */ 40*0a6a1f1dSLionel Sambuc /* Upper 16 bits are garbage */ 41*0a6a1f1dSLionel Sambuc return (x + (x >> 8)) & 0xFF; /* (8 significant bits) */ 42*0a6a1f1dSLionel Sambuc } 43*0a6a1f1dSLionel Sambuc 44*0a6a1f1dSLionel Sambuc #endif /* CRT_HAS_128BIT */ 45