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author | The Android Open Source Project <initial-contribution@android.com> | 2008-10-21 07:00:00 -0700 |
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committer | The Android Open Source Project <initial-contribution@android.com> | 2008-10-21 07:00:00 -0700 |
commit | 7c1b96a165f970a09ed239bb4fb3f1b0d8f2a407 (patch) | |
tree | df5a6539447324de36e95b057d6b9f0361b7a250 /libs/surfaceflinger/clz.cpp | |
download | frameworks_native-7c1b96a165f970a09ed239bb4fb3f1b0d8f2a407.zip frameworks_native-7c1b96a165f970a09ed239bb4fb3f1b0d8f2a407.tar.gz frameworks_native-7c1b96a165f970a09ed239bb4fb3f1b0d8f2a407.tar.bz2 |
Initial Contribution
Diffstat (limited to 'libs/surfaceflinger/clz.cpp')
-rw-r--r-- | libs/surfaceflinger/clz.cpp | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/libs/surfaceflinger/clz.cpp b/libs/surfaceflinger/clz.cpp new file mode 100644 index 0000000..2456b86 --- /dev/null +++ b/libs/surfaceflinger/clz.cpp @@ -0,0 +1,37 @@ +/* + * Copyright (C) 2007 The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include "clz.h" + +namespace android { + +int clz_impl(int32_t x) +{ +#if defined(__arm__) && !defined(__thumb__) + return __builtin_clz(x); +#else + if (!x) return 32; + int e = 31; + if (x&0xFFFF0000) { e -=16; x >>=16; } + if (x&0x0000FF00) { e -= 8; x >>= 8; } + if (x&0x000000F0) { e -= 4; x >>= 4; } + if (x&0x0000000C) { e -= 2; x >>= 2; } + if (x&0x00000002) { e -= 1; } + return e; +#endif +} + +}; // namespace android |