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9bf37cc971
License boilerplate update to follow. Change-Id: I2810460c11a58b6d148d84673cc031f3685e79b5
99 lines
3.7 KiB
C
99 lines
3.7 KiB
C
/*************************** Fraunhofer IIS FDK Tools **********************
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(C) Copyright Fraunhofer IIS (2005)
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All Rights Reserved
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Please be advised that this software and/or program delivery is
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Confidential Information of Fraunhofer and subject to and covered by the
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Fraunhofer IIS Software Evaluation Agreement
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between Google Inc. and Fraunhofer
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effective and in full force since March 1, 2012.
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You may use this software and/or program only under the terms and
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conditions described in the above mentioned Fraunhofer IIS Software
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Evaluation Agreement. Any other and/or further use requires a separate agreement.
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$Id$
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Author(s):
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Description: bitreversal of input data
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This software and/or program is protected by copyright law and international
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treaties. Any reproduction or distribution of this software and/or program,
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or any portion of it, may result in severe civil and criminal penalties, and
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will be prosecuted to the maximum extent possible under law.
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******************************************************************************/
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#if defined(FUNCTION_scramble)
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#if defined(__GNUC__) /* cppp replaced: elif */
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#define FUNCTION_scramble
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#if defined(__ARM_ARCH_5TE__)
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#define USE_LDRD_STRD /* LDRD requires 8 byte data alignment. */
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#endif
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inline void scramble(FIXP_DBL x [], INT n) {
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FDK_ASSERT(!(((INT)x)&(ALIGNMENT_DEFAULT-1)));
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asm("mov r2, #1;\n" /* r2(m) = 1; */
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"sub r3, %1, #1;\n" /* r3 = n-1; */
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"mov r4, #0;\n" /* r4(j) = 0; */
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"scramble_m_loop%=:\n" /* { */
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"mov r5, %1;\n" /* r5(k) = 1; */
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"scramble_k_loop%=:\n" /* { */
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"mov r5, r5, lsr #1;\n" /* k >>= 1; */
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"eor r4, r4, r5;\n" /* j ^=k; */
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"ands r10, r4, r5;\n" /* r10 = r4 & r5; */
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"beq scramble_k_loop%=;\n" /* } while (r10 == 0); */
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"cmp r4, r2;\n" /* if (r4 < r2) break; */
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"bcc scramble_m_loop_end%=;\n"
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#ifdef USE_LDRD_STRD
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"mov r5, r2, lsl #3;\n" /* m(r5) = r2*4*2 */
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"ldrd r10, [%0, r5];\n" /* r10 = x[r5], x7 = x[r5+1] */
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"mov r6, r4, lsl #3;\n" /* j(r6) = r4*4*2 */
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"ldrd r8, [%0, r6];\n" /* r8 = x[r6], r9 = x[r6+1]; */
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"strd r10, [%0, r6];\n" /* x[r6,r6+1] = r10,r11; */
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"strd r8, [%0, r5];\n" /* x[r5,r5+1] = r8,r9; */
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#else
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"mov r5, r2, lsl #3;\n" /* m(r5) = r2*4*2 */
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"ldr r10, [%0, r5];\n"
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"mov r6, r4, lsl #3;\n" /* j(r6) = r4*4*2 */
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"ldr r11, [%0, r6];\n"
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"str r10, [%0, r6];\n"
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"str r11, [%0, r5];\n"
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"add r5, r5, #4;"
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"ldr r10, [%0, r5];\n"
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"add r6, r6, #4;"
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"ldr r11, [%0, r6];\n"
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"str r10, [%0, r6];\n"
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"str r11, [%0, r5];\n"
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#endif
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"scramble_m_loop_end%=:\n"
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"add r2, r2, #1;\n" /* r2++; */
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"cmp r2, r3;\n"
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"bcc scramble_m_loop%=;\n" /* } while (r2(m) < r3(n-1)); */
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:
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: "r"(x), "r"(n)
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#ifdef USE_LDRD_STRD
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: "r2","r3", "r4","r5", "r10","r11", "r8","r9", "r6" );
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#else
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: "r2","r3", "r4","r5", "r10","r11", "r6" );
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#endif
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}
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#else
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/* Force C implementation if no assembler version available. */
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#undef FUNCTION_scramble
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#endif /* Toolchain selection. */
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#endif /* defined(FUNCTION_scramble) */
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