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+/* ------------------------------------------------------------------
+ * Copyright (C) 1998-2009 PacketVideo
+ *
+ * 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.
+ * -------------------------------------------------------------------
+ */
+/*
+------------------------------------------------------------------------------
+ PacketVideo Corp.
+ MP3 Decoder Library
+
+ Filename: pvmp3_normalize.cpp
+
+ Date: 10/02/2007
+
+------------------------------------------------------------------------------
+ REVISION HISTORY
+
+
+ Description:
+
+------------------------------------------------------------------------------
+ INPUT AND OUTPUT DEFINITIONS
+
+Input
+ Int32 x 32-bit integer non-zero input
+Returns
+ Int32 i number of leading zeros on x
+
+
+------------------------------------------------------------------------------
+ FUNCTION DESCRIPTION
+
+ Returns number of leading zeros on the non-zero input
+
+------------------------------------------------------------------------------
+ REQUIREMENTS
+
+
+------------------------------------------------------------------------------
+ REFERENCES
+
+------------------------------------------------------------------------------
+ PSEUDO-CODE
+
+------------------------------------------------------------------------------
+*/
+
+
+/*----------------------------------------------------------------------------
+; INCLUDES
+----------------------------------------------------------------------------*/
+
+#include "pvmp3_audio_type_defs.h"
+#include "pvmp3_normalize.h"
+
+/*----------------------------------------------------------------------------
+; MACROS
+; Define module specific macros here
+----------------------------------------------------------------------------*/
+
+
+/*----------------------------------------------------------------------------
+; DEFINES
+; Include all pre-processor statements here. Include conditional
+; compile variables also.
+----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------
+; LOCAL FUNCTION DEFINITIONS
+; Function Prototype declaration
+----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------
+; LOCAL STORE/BUFFER/POINTER DEFINITIONS
+; Variable declaration - defined here and used outside this module
+----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------
+; EXTERNAL FUNCTION REFERENCES
+; Declare functions defined elsewhere and referenced in this module
+----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------
+; EXTERNAL GLOBAL STORE/BUFFER/POINTER REFERENCES
+; Declare variables used in this module but defined elsewhere
+----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------
+; FUNCTION CODE
+----------------------------------------------------------------------------*/
+
+#if (defined(PV_ARM_V5)||defined(PV_ARM_V4))
+#elif (defined(PV_ARM_GCC_V5)||defined(PV_ARM_GCC_V4))
+
+
+/* function is inlined in header file */
+
+
+#else
+
+int32 pvmp3_normalize(int32 x)
+{
+ /*----------------------------------------------------------------------------
+ ; Define all local variables
+ ----------------------------------------------------------------------------*/
+ int32 i;
+
+
+ if (x > 0x0FFFFFFF)
+ {
+ i = 0; /* most likely case */
+ }
+ else if (x > 0x00FFFFFF)
+ {
+ i = 3; /* second most likely case */
+ }
+ else if (x > 0x0000FFFF)
+ {
+ i = x > 0x000FFFFF ? 7 : 11;
+ }
+ else
+ {
+ if (x > 0x000000FF)
+ {
+ i = x > 0x00000FFF ? 15 : 19;
+ }
+ else
+ {
+ i = x > 0x0000000F ? 23 : 27;
+ }
+ }
+
+
+ x <<= i;
+
+ switch (x & 0x78000000)
+ {
+ case 0x08000000:
+ i += 3;
+ break;
+
+ case 0x18000000:
+ case 0x10000000:
+ i += 2;
+ break;
+ case 0x28000000:
+ case 0x20000000:
+ case 0x38000000:
+ case 0x30000000:
+ i++;
+
+ default:
+ ;
+ }
+
+ return i;
+
+}
+
+#endif
+