/* * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #ifndef OS_CPU_SOLARIS_SPARC_VM_COUNTTRAILINGZEROS_HPP #define OS_CPU_SOLARIS_SPARC_VM_COUNTTRAILINGZEROS_HPP #include "utilities/globalDefinitions.hpp" inline unsigned count_trailing_zeros(uintx x) { assert(x != 0, "precondition"); // Reduce to mask with ones in all positions below the least // significant set bit of x, and zeros otherwise. uintx rx = (x - 1) & ~x; // sub x, 1, rx; andn rx, x, rx; // Then count the set bits in the reduction. uintx result; __asm__(" popc %1, %0\n\t" : "=r" (result) : "r" (rx)); return result; } #endif // include guard