Merge pull request #1630 from nico/neon-reversible

NEON-optimize 5-3 IDWT

Author: rouault

src/lib/openjp2/dwt.c

@@ -76,7 +76,7 @@
 /** Number of int32 values in a AVX2 register */
 #define VREG_INT_COUNT       8
 #else
-/** Number of int32 values in a SSE2 register */
+/** Number of int32 values in a SSE2 or NEON register */
 #define VREG_INT_COUNT       4
 #endif
 
@@ -702,7 +702,7 @@ static void opj_idwt53_h(const opj_dwt_t *dwt,
 #endif
 }
 
-#if (defined(__SSE2__) || defined(__AVX2__) || defined(__AVX512F__)) && !defined(STANDARD_SLOW_VERSION)
+#if (defined(__ARM_NEON) || defined(__SSE2__) || defined(__AVX2__) || defined(__AVX512F__)) && !defined(STANDARD_SLOW_VERSION)
 
 /* Conveniency macros to improve the readability of the formulas */
 #if defined(__AVX512F__)
@@ -725,6 +725,16 @@ static void opj_idwt53_h(const opj_dwt_t *dwt,
 #define ADD(x,y)    _mm256_add_epi32((x),(y))
 #define SUB(x,y)    _mm256_sub_epi32((x),(y))
 #define SAR(x,y)    _mm256_srai_epi32((x),(y))
+#elif defined(__ARM_NEON)
+#define VREG        int32x4_t
+#define LOAD_CST(x) vdupq_n_s32(x)
+#define LOAD(x)     vld1q_s32((const int32_t*)(x))
+#define LOADU(x)    vld1q_s32((const int32_t*)(x))
+#define STORE(x,y)  vst1q_s32((int32_t*)(x),(y))
+#define STOREU(x,y) vst1q_s32((int32_t*)(x),(y))
+#define ADD(x,y)    vaddq_s32((x),(y))
+#define SUB(x,y)    vsubq_s32((x),(y))
+#define SAR(x,y)    vshrq_n_s32((x),(y))
 #else
 #define VREG        __m128i
 #define LOAD_CST(x) _mm_set1_epi32(x)
@@ -758,9 +768,9 @@ void opj_idwt53_v_final_memcpy(OPJ_INT32* tiledp_col,
     }
 }
 
-/** Vertical inverse 5x3 wavelet transform for 8 columns in SSE2, or
- * 16 in AVX2, when top-most pixel is on even coordinate */
-static void opj_idwt53_v_cas0_mcols_SSE2_OR_AVX2(
+/** Vertical inverse 5x3 wavelet transform for 8 columns in SSE2 and NEON,
+ * or 16 in AVX2, when top-most pixel is on even coordinate */
+static void opj_idwt53_v_cas0_mcols_SIMD(
     OPJ_INT32* tmp,
     const OPJ_INT32 sn,
     const OPJ_INT32 len,
@@ -865,9 +875,9 @@ static void opj_idwt53_v_cas0_mcols_SSE2_OR_AVX2(
 }
 
 
-/** Vertical inverse 5x3 wavelet transform for 8 columns in SSE2, or
- * 16 in AVX2, when top-most pixel is on odd coordinate */
-static void opj_idwt53_v_cas1_mcols_SSE2_OR_AVX2(
+/** Vertical inverse 5x3 wavelet transform for 8 columns in SSE2 and NEON,
+ * or 16 in AVX2, when top-most pixel is on odd coordinate */
+static void opj_idwt53_v_cas1_mcols_SIMD(
     OPJ_INT32* tmp,
     const OPJ_INT32 sn,
     const OPJ_INT32 len,
@@ -1107,11 +1117,11 @@ static void opj_idwt53_v(const opj_dwt_t *dwt,
     if (dwt->cas == 0) {
         /* If len == 1, unmodified value */
 
-#if (defined(__SSE2__) || defined(__AVX2__))
+#if (defined(__ARM_NEON) || defined(__SSE2__) || defined(__AVX2__))
         if (len > 1 && nb_cols == PARALLEL_COLS_53) {
-            /* Same as below general case, except that thanks to SSE2/AVX2 */
+            /* Same as below general case, except that thanks to SIMD */
             /* we can efficiently process 8/16 columns in parallel */
-            opj_idwt53_v_cas0_mcols_SSE2_OR_AVX2(dwt->mem, sn, len, tiledp_col, stride);
+            opj_idwt53_v_cas0_mcols_SIMD(dwt->mem, sn, len, tiledp_col, stride);
             return;
         }
 #endif
@@ -1150,11 +1160,11 @@ static void opj_idwt53_v(const opj_dwt_t *dwt,
             return;
         }
 
-#if (defined(__SSE2__) || defined(__AVX2__))
+#if (defined(__ARM_NEON) || defined(__SSE2__) || defined(__AVX2__))
         if (len > 2 && nb_cols == PARALLEL_COLS_53) {
-            /* Same as below general case, except that thanks to SSE2/AVX2 */
+            /* Same as below general case, except that thanks to SIMD */
             /* we can efficiently process 8/16 columns in parallel */
-            opj_idwt53_v_cas1_mcols_SSE2_OR_AVX2(dwt->mem, sn, len, tiledp_col, stride);
+            opj_idwt53_v_cas1_mcols_SIMD(dwt->mem, sn, len, tiledp_col, stride);
             return;
         }
 #endif