| /* |
| * 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 |