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Diffstat (limited to 'libFDK/include/arm/scramble.h')
| -rw-r--r-- | libFDK/include/arm/scramble.h | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/libFDK/include/arm/scramble.h b/libFDK/include/arm/scramble.h new file mode 100644 index 0000000..9143155 --- /dev/null +++ b/libFDK/include/arm/scramble.h @@ -0,0 +1,98 @@ +/*************************** Fraunhofer IIS FDK Tools ********************** + + (C) Copyright Fraunhofer IIS (2005) + All Rights Reserved + + Please be advised that this software and/or program delivery is + Confidential Information of Fraunhofer and subject to and covered by the + + Fraunhofer IIS Software Evaluation Agreement + between Google Inc. and Fraunhofer + effective and in full force since March 1, 2012. + + You may use this software and/or program only under the terms and + conditions described in the above mentioned Fraunhofer IIS Software + Evaluation Agreement. Any other and/or further use requires a separate agreement. + + + $Id$ + Author(s): + Description: bitreversal of input data + + This software and/or program is protected by copyright law and international + treaties. Any reproduction or distribution of this software and/or program, + or any portion of it, may result in severe civil and criminal penalties, and + will be prosecuted to the maximum extent possible under law. + +******************************************************************************/ + + + +#if defined(FUNCTION_scramble) +#if defined(__GNUC__) /* cppp replaced: elif */ + +#define FUNCTION_scramble + +#if defined(__ARM_ARCH_5TE__) +#define USE_LDRD_STRD /* LDRD requires 8 byte data alignment. */ +#endif + +inline void scramble(FIXP_DBL x [], INT n) { + FDK_ASSERT(!(((INT)x)&(ALIGNMENT_DEFAULT-1))); + asm("mov r2, #1;\n" /* r2(m) = 1; */ + "sub r3, %1, #1;\n" /* r3 = n-1; */ + "mov r4, #0;\n" /* r4(j) = 0; */ + +"scramble_m_loop%=:\n" /* { */ + "mov r5, %1;\n" /* r5(k) = 1; */ + +"scramble_k_loop%=:\n" /* { */ + "mov r5, r5, lsr #1;\n" /* k >>= 1; */ + "eor r4, r4, r5;\n" /* j ^=k; */ + "ands r10, r4, r5;\n" /* r10 = r4 & r5; */ + "beq scramble_k_loop%=;\n" /* } while (r10 == 0); */ + + "cmp r4, r2;\n" /* if (r4 < r2) break; */ + "bcc scramble_m_loop_end%=;\n" + +#ifdef USE_LDRD_STRD + "mov r5, r2, lsl #3;\n" /* m(r5) = r2*4*2 */ + "ldrd r10, [%0, r5];\n" /* r10 = x[r5], x7 = x[r5+1] */ + "mov r6, r4, lsl #3;\n" /* j(r6) = r4*4*2 */ + "ldrd r8, [%0, r6];\n" /* r8 = x[r6], r9 = x[r6+1]; */ + "strd r10, [%0, r6];\n" /* x[r6,r6+1] = r10,r11; */ + "strd r8, [%0, r5];\n" /* x[r5,r5+1] = r8,r9; */ +#else + "mov r5, r2, lsl #3;\n" /* m(r5) = r2*4*2 */ + "ldr r10, [%0, r5];\n" + "mov r6, r4, lsl #3;\n" /* j(r6) = r4*4*2 */ + "ldr r11, [%0, r6];\n" + + "str r10, [%0, r6];\n" + "str r11, [%0, r5];\n" + + "add r5, r5, #4;" + "ldr r10, [%0, r5];\n" + "add r6, r6, #4;" + "ldr r11, [%0, r6];\n" + "str r10, [%0, r6];\n" + "str r11, [%0, r5];\n" +#endif +"scramble_m_loop_end%=:\n" + "add r2, r2, #1;\n" /* r2++; */ + "cmp r2, r3;\n" + "bcc scramble_m_loop%=;\n" /* } while (r2(m) < r3(n-1)); */ + : + : "r"(x), "r"(n) +#ifdef USE_LDRD_STRD + : "r2","r3", "r4","r5", "r10","r11", "r8","r9", "r6" ); +#else + : "r2","r3", "r4","r5", "r10","r11", "r6" ); +#endif +} +#else +/* Force C implementation if no assembler version available. */ +#undef FUNCTION_scramble +#endif /* Toolchain selection. */ + +#endif /* defined(FUNCTION_scramble) */ |