From 37a6a455466e5b197311771a777ab241e471ed8a Mon Sep 17 00:00:00 2001 From: Edward O'Callaghan Date: Fri, 7 Aug 2009 20:30:09 +0000 Subject: Code style and Readability fixes. Credit to Craig van Vliet. git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@78403 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/popcountti2.c | 43 ++++++++++++++++++++++--------------------- 1 file changed, 22 insertions(+), 21 deletions(-) (limited to 'lib/popcountti2.c') diff --git a/lib/popcountti2.c b/lib/popcountti2.c index 9ac052d9..16f89b7a 100644 --- a/lib/popcountti2.c +++ b/lib/popcountti2.c @@ -1,21 +1,22 @@ -//===-- popcountti2.c - Implement __popcountti2 ----------------------------===// -// -// The LLVM Compiler Infrastructure -// -// This file is distributed under the University of Illinois Open Source -// License. See LICENSE.TXT for details. -// -//===----------------------------------------------------------------------===// -// -// This file implements __popcountti2 for the compiler_rt library. -// -//===----------------------------------------------------------------------===// +/* ===-- popcountti2.c - Implement __popcountti2 ----------------------------=== + * + * The LLVM Compiler Infrastructure + * + * This file is distributed under the University of Illinois Open Source + * License. See LICENSE.TXT for details. + * + * ===----------------------------------------------------------------------=== + * + * This file implements __popcountti2 for the compiler_rt library. + * + * ===----------------------------------------------------------------------=== + */ #if __x86_64 #include "int_lib.h" -// Returns: count of 1 bits +/* Returns: count of 1 bits */ si_int __popcountti2(ti_int a) @@ -23,21 +24,21 @@ __popcountti2(ti_int a) tu_int x3 = (tu_int)a; x3 = x3 - ((x3 >> 1) & (((tu_int)0x5555555555555555uLL << 64) | 0x5555555555555555uLL)); - // Every 2 bits holds the sum of every pair of bits (64) + /* Every 2 bits holds the sum of every pair of bits (64) */ x3 = ((x3 >> 2) & (((tu_int)0x3333333333333333uLL << 64) | 0x3333333333333333uLL)) + (x3 & (((tu_int)0x3333333333333333uLL << 64) | 0x3333333333333333uLL)); - // Every 4 bits holds the sum of every 4-set of bits (3 significant bits) (32) + /* Every 4 bits holds the sum of every 4-set of bits (3 significant bits) (32) */ x3 = (x3 + (x3 >> 4)) & (((tu_int)0x0F0F0F0F0F0F0F0FuLL << 64) | 0x0F0F0F0F0F0F0F0FuLL); - // Every 8 bits holds the sum of every 8-set of bits (4 significant bits) (16) + /* Every 8 bits holds the sum of every 8-set of bits (4 significant bits) (16) */ du_int x2 = (du_int)(x3 + (x3 >> 64)); - // Every 8 bits holds the sum of every 8-set of bits (5 significant bits) (8) + /* Every 8 bits holds the sum of every 8-set of bits (5 significant bits) (8) */ su_int x = (su_int)(x2 + (x2 >> 32)); - // Every 8 bits holds the sum of every 8-set of bits (6 significant bits) (4) + /* Every 8 bits holds the sum of every 8-set of bits (6 significant bits) (4) */ x = x + (x >> 16); - // Every 8 bits holds the sum of every 8-set of bits (7 significant bits) (2) - // Upper 16 bits are garbage - return (x + (x >> 8)) & 0xFF; // (8 significant bits) + /* Every 8 bits holds the sum of every 8-set of bits (7 significant bits) (2) */ + /* Upper 16 bits are garbage */ + return (x + (x >> 8)) & 0xFF; /* (8 significant bits) */ } #endif -- cgit v1.2.3