DSP: Fine tune fixed-point non-power-of-2 CFFT for GCC 4.9.0

    Now Ne10 provides inline assembly for fixed-point non-power-of-2
    Complex FFT, on AArch64. For GCC 4.9.0, user can define
    NE10_INLINE_ASM_OPT to enable this optimization.
    Below is performance data with or without this
    optimization.

    Cortex-A53 AArch64 mode (1.69GHz)
    GCC 4.9.0, with -O2
    Android-21, AArch64

    | C2C FFT Time Cost|
    |             in ms|
    |size|         Ne10|
    |    |Without| With|
    |  60|   4.67| 2.91|
    | 120|   5.79| 3.37|
    | 240|   5.57| 3.30|
    | 480|   6.76| 3.87|
    | 970|   6.89| 4.00|

Change-Id: I4f74217b026d8ef6ab6af4e1fb178ce4f1398b50

diff --git a/modules/dsp/NE10_fft_generic_int32.neonintrinsic.h b/modules/dsp/NE10_fft_generic_int32.neonintrinsic.h
index 8b244cb..c28265d 100644 (file)
--- a/modules/dsp/NE10_fft_generic_int32.neonintrinsic.h
+++ b/modules/dsp/NE10_fft_generic_int32.neonintrinsic.h
@@ -59,11 +59,47 @@ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 typedef int32x4x2_t CPLX;
 typedef int32x4_t   REAL;
 #define NE10_REAL_DUP_NEON_S32 vdupq_n_s32
+
+#ifndef NE10_INLINE_ASM_OPT
 #define NE10_CPLX_LOAD(PTR) vld2q_s32 ((ne10_int32_t*) (PTR))
 #define NE10_CPLX_STORE(PTR,OUT) \
     do { \
         vst2q_s32 ((ne10_int32_t*) (PTR), OUT); \
     } while (0)
+#else // NE10_INLINE_ASM_OPT
+#ifndef __aarch64__
+#error Currently, inline assembly optimizations are only available on AArch64.
+#else // __aarch64__
+template<class T>
+inline static int32x4x2_t NE10_CPLX_LOAD(T *ptr)
+{
+    int32x4x2_t result;
+    asm volatile (
+        "ld2 {v0.4s, v1.4s}, [%[pin]] \n\t"
+        "mov %[r].16b, v0.16b \n\t"
+        "mov %[i].16b, v1.16b \n\t"
+    : [r]"+w"(result.val[0]),
+      [i]"+w"(result.val[1])
+    : [pin]"r"(ptr)
+    : "memory", "v0", "v1");
+    return result;
+}
+
+template<class T>
+inline static void NE10_CPLX_STORE(T *ptr, int32x4x2_t out)
+{
+    asm volatile (
+        "mov v0.16b, %[r].16b  \n\t"
+        "mov v1.16b, %[i].16b  \n\t"
+        "st2 {v0.4s, v1.4s}, [%[pout]] \n\t"
+    : [r]"+w"(out.val[0]),
+      [i]"+w"(out.val[1])
+    : [pout]"r"(ptr)
+    : "memory", "v0", "v1");
+}
+
+#endif // __aarch64__
+#endif // NE10_INLINE_ASM_OPT
 
 template<>
 inline CPLX NE10_CPX_LOAD_S<CPLX> (const CPLX *ptr)