Renesas
Fork of mbed-dsp. CMSIS-DSP library of supporting NEON
Dependents: mbed-os-example-cmsis_dsp_neon
Fork of
mbed-dsp
by 
mbed official
Information
Japanese version is available in lower part of this page.
このページの後半に日本語版が用意されています．
CMSIS-DSP of supporting NEON
What is this ?
A library for CMSIS-DSP of supporting NEON.
We supported the NEON to CMSIS-DSP Ver1.4.3(CMSIS V4.1) that ARM supplied, has achieved the processing speed improvement.
If you use the mbed-dsp library, you can use to replace this library.
CMSIS-DSP of supporting NEON is provied as a library.
Library Creation environment
CMSIS-DSP library of supporting NEON was created by the following environment.
- Compiler
ARMCC Version 5.03 - Compile option switch[C Compiler]
-DARM_MATH_MATRIX_CHECK -DARM_MATH_ROUNDING -O3 -Otime --cpu=Cortex-A9 --littleend --arm --apcs=/interwork --no_unaligned_access --fpu=vfpv3_fp16 --fpmode=fast --apcs=/hardfp --vectorize --asm
- Compile option switch[Assembler]
--cpreproc --cpu=Cortex-A9 --littleend --arm --apcs=/interwork --no_unaligned_access --fpu=vfpv3_fp16 --fpmode=fast --apcs=/hardfp
Effects of NEON support
In the data which passes to each function, large size will be expected more effective than small size.
Also if the data is a multiple of 16, effect will be expected in every function in the CMSIS-DSP.
NEON対応CMSIS-DSP
概要
NEON対応したCMSIS-DSPのライブラリです。
ARM社提供のCMSIS-DSP Ver1.4.3(CMSIS V4.1)をターゲットにNEON対応を行ない、処理速度向上を実現しております。
mbed-dspライブラリを使用している場合は、本ライブラリに置き換えて使用することができます。
NEON対応したCMSIS-DSPはライブラリで提供します。
ライブラリ作成環境
NEON対応CMSIS-DSPライブラリは、以下の環境で作成しています。
- コンパイラ
ARMCC Version 5.03 - コンパイルオプションスイッチ[C Compiler]
-DARM_MATH_MATRIX_CHECK -DARM_MATH_ROUNDING -O3 -Otime --cpu=Cortex-A9 --littleend --arm --apcs=/interwork --no_unaligned_access --fpu=vfpv3_fp16 --fpmode=fast --apcs=/hardfp --vectorize --asm
- コンパイルオプションスイッチ[Assembler]
--cpreproc --cpu=Cortex-A9 --littleend --arm --apcs=/interwork --no_unaligned_access --fpu=vfpv3_fp16 --fpmode=fast --apcs=/hardfp
NEON対応による効果について
CMSIS-DSP内の各関数へ渡すデータは、小さいサイズよりも大きいサイズの方が効果が見込めます。
また、16の倍数のデータであれば、CMSIS-DSP内のどの関数でも効果が見込めます。
Diff: cmsis_dsp/BasicMathFunctions/arm_abs_q7.c
- Revision:
- 1:fdd22bb7aa52
- Child:
- 2:da51fb522205
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/cmsis_dsp/BasicMathFunctions/arm_abs_q7.c Wed Nov 28 12:30:09 2012 +0000
@@ -0,0 +1,152 @@
+/* ----------------------------------------------------------------------
+* Copyright (C) 2010 ARM Limited. All rights reserved.
+*
+* $Date: 15. February 2012
+* $Revision: V1.1.0
+*
+* Project: CMSIS DSP Library
+* Title: arm_abs_q7.c
+*
+* Description: Q7 vector absolute value.
+*
+* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
+*
+* Version 1.1.0 2012/02/15
+* Updated with more optimizations, bug fixes and minor API changes.
+*
+* Version 1.0.10 2011/7/15
+* Big Endian support added and Merged M0 and M3/M4 Source code.
+*
+* Version 1.0.3 2010/11/29
+* Re-organized the CMSIS folders and updated documentation.
+*
+* Version 1.0.2 2010/11/11
+* Documentation updated.
+*
+* Version 1.0.1 2010/10/05
+* Production release and review comments incorporated.
+*
+* Version 1.0.0 2010/09/20
+* Production release and review comments incorporated.
+*
+* Version 0.0.7 2010/06/10
+* Misra-C changes done
+* -------------------------------------------------------------------- */
+
+#include "arm_math.h"
+
+/**
+ * @ingroup groupMath
+ */
+
+/**
+ * @addtogroup BasicAbs
+ * @{
+ */
+
+/**
+ * @brief Q7 vector absolute value.
+ * @param[in] *pSrc points to the input buffer
+ * @param[out] *pDst points to the output buffer
+ * @param[in] blockSize number of samples in each vector
+ * @return none.
+ *
+ * \par Conditions for optimum performance
+ * Input and output buffers should be aligned by 32-bit
+ *
+ *
+ * <b>Scaling and Overflow Behavior:</b>
+ * \par
+ * The function uses saturating arithmetic.
+ * The Q7 value -1 (0x80) will be saturated to the maximum allowable positive value 0x7F.
+ */
+
+void arm_abs_q7(
+ q7_t * pSrc,
+ q7_t * pDst,
+ uint32_t blockSize)
+{
+ uint32_t blkCnt; /* loop counter */
+ q7_t in; /* Input value1 */
+
+#ifndef ARM_MATH_CM0
+
+ /* Run the below code for Cortex-M4 and Cortex-M3 */
+ q31_t in1, in2, in3, in4; /* temporary input variables */
+ q31_t out1, out2, out3, out4; /* temporary output variables */
+
+ /*loop Unrolling */
+ blkCnt = blockSize >> 2u;
+
+ /* First part of the processing with loop unrolling. Compute 4 outputs at a time.
+ ** a second loop below computes the remaining 1 to 3 samples. */
+ while(blkCnt > 0u)
+ {
+ /* C = |A| */
+ /* Read inputs */
+ in1 = (q31_t) * pSrc;
+ in2 = (q31_t) * (pSrc + 1);
+ in3 = (q31_t) * (pSrc + 2);
+
+ /* find absolute value */
+ out1 = (in1 > 0) ? in1 : __QSUB8(0, in1);
+
+ /* read input */
+ in4 = (q31_t) * (pSrc + 3);
+
+ /* find absolute value */
+ out2 = (in2 > 0) ? in2 : __QSUB8(0, in2);
+
+ /* store result to destination */
+ *pDst = (q7_t) out1;
+
+ /* find absolute value */
+ out3 = (in3 > 0) ? in3 : __QSUB8(0, in3);
+
+ /* find absolute value */
+ out4 = (in4 > 0) ? in4 : __QSUB8(0, in4);
+
+ /* store result to destination */
+ *(pDst + 1) = (q7_t) out2;
+
+ /* store result to destination */
+ *(pDst + 2) = (q7_t) out3;
+
+ /* store result to destination */
+ *(pDst + 3) = (q7_t) out4;
+
+ /* update pointers to process next samples */
+ pSrc += 4u;
+ pDst += 4u;
+
+ /* Decrement the loop counter */
+ blkCnt--;
+ }
+
+ /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
+ ** No loop unrolling is used. */
+ blkCnt = blockSize % 0x4u;
+#else
+
+ /* Run the below code for Cortex-M0 */
+ blkCnt = blockSize;
+
+#endif // #define ARM_MATH_CM0
+
+ while(blkCnt > 0u)
+ {
+ /* C = |A| */
+ /* Read the input */
+ in = *pSrc++;
+
+ /* Store the Absolute result in the destination buffer */
+ *pDst++ = (in > 0) ? in : ((in == (q7_t) 0x80) ? 0x7f : -in);
+
+ /* Decrement the loop counter */
+ blkCnt--;
+ }
+}
+
+/**
+ * @} end of BasicAbs group
+ */