From 122b335f58e2f52d542854dcddef8723a2b213a4 Mon Sep 17 00:00:00 2001
From: David 'Digit' Turner <digit@android.com>
Date: Sun, 16 Jan 2011 16:25:10 +0100
Subject: Sligh speedup for pixel conversion routines with Duff's device.

Change-Id: If832bc5844945f7a2027b2f8d09393586545d8d5
---
 android/utils/duff.h | 71 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 71 insertions(+)
 create mode 100644 android/utils/duff.h

(limited to 'android/utils')

diff --git a/android/utils/duff.h b/android/utils/duff.h
new file mode 100644
index 0000000..a00768c
--- /dev/null
+++ b/android/utils/duff.h
@@ -0,0 +1,71 @@
+/* Copyright (C) 2011 The Android Open Source Project
+**
+** This software is licensed under the terms of the GNU General Public
+** License version 2, as published by the Free Software Foundation, and
+** may be copied, distributed, and modified under those terms.
+**
+** This program 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 for more details.
+*/
+#ifndef ANDROID_UTILS_DUFF_H
+#define ANDROID_UTILS_DUFF_H
+
+/*********************************************************************
+ *********************************************************************
+ *****
+ *****    DUFF'S DEVICES
+ *****
+ *****/
+
+#define  DUFF1(_count,_stmnt) \
+    do { \
+        int __n = (_count); \
+        do { \
+            _stmnt; \
+        } while (--__n > 0); \
+    } while (0);
+
+#define  DUFF2(_count,_stmnt)  \
+    ({ \
+        int   __count = (_count); \
+        int   __n     = (__count +1)/2; \
+        switch (__count & 1) { \
+        case 0: do { _stmnt; \
+        case 1:      _stmnt; \
+                } while (--__n > 0); \
+        } \
+    })
+
+#define  DUFF4(_count,_stmnt)  \
+    ({ \
+        int   __count = (_count); \
+        int   __n     = (__count +3)/4; \
+        switch (__count & 3) { \
+        case 0: do { _stmnt; \
+        case 3:      _stmnt; \
+        case 2:      _stmnt; \
+        case 1:      _stmnt; \
+                } while (--__n > 0); \
+        } \
+    })
+
+#define  DUFF8(_count,_stmnt)  \
+    ({ \
+        int   __count = (_count); \
+        int   __n     = (__count+7)/8; \
+        switch (__count & 7) { \
+        case 0: do { _stmnt; \
+        case 7:      _stmnt; \
+        case 6:      _stmnt; \
+        case 5:      _stmnt; \
+        case 4:      _stmnt; \
+        case 3:      _stmnt; \
+        case 2:      _stmnt; \
+        case 1:      _stmnt; \
+                } while (--__n > 0); \
+        } \
+    })
+
+#endif /* ANDROID_UTILS_DUFF_H */
-- 
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