add missing bit from commit r7423

Originally committed as revision 7424 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/armv4l/mpegvideo_armv5te.c

+/*
+ * Optimization of some functions from mpegvideo.c for armv5te
+ * Copyright (c) 2007 Siarhei Siamashka <ssvb@users.sourceforge.net>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/*
+ * Some useful links for those who may be interested in optimizing code for ARM.
+ * ARM Architecture Reference Manual: http://www.arm.com/community/academy/resources.html
+ * Instructions timings and optimization guide for ARM9E: http://www.arm.com/pdfs/DDI0222B_9EJS_r1p2.pdf
+ */
+
+#include "../dsputil.h"
+#include "../mpegvideo.h"
+#include "../avcodec.h"
+
+
+#ifdef ENABLE_ARM_TESTS
+/**
+ * h263 dequantizer supplementary function, it is performance critical and needs to
+ * have optimized implementations for each architecture. Is also used as a reference
+ * implementation in regression tests
+ */
+static inline void dct_unquantize_h263_helper_c(DCTELEM *block, int qmul, int qadd, int count)
+{
+    int i, level;
+    for (i = 0; i < count; i++) {
+        level = block[i];
+        if (level) {
+            if (level < 0) {
+                level = level * qmul - qadd;
+            } else {
+                level = level * qmul + qadd;
+            }
+            block[i] = level;
+        }
+    }
+}
+#endif
+
+/* GCC 3.1 or higher is required to support symbolic names in assembly code */
+#if (__GNUC__ > 3) || ((__GNUC__ == 3) && (__GNUC_MINOR__ >= 1))
+
+/**
+ * Special optimized version of dct_unquantize_h263_helper_c, it requires the block
+ * to be at least 8 bytes aligned, and may process more elements than requested.
+ * But it is guaranteed to never process more than 64 elements provided that
+ * xxcount argument is <= 64, so it is safe. This macro is optimized for a common
+ * distribution of values for nCoeffs (they are mostly multiple of 8 plus one or
+ * two extra elements). So this macro processes data as 8 elements per loop iteration
+ * and contains optional 2 elements processing in the end.
+ *
+ * Inner loop should take 6 cycles per element on arm926ej-s (Nokia 770)
+ */
+#define dct_unquantize_h263_special_helper_armv5te(xxblock, xxqmul, xxqadd, xxcount) \
+({ DCTELEM *xblock = xxblock; \
+   int xqmul = xxqmul, xqadd = xxqadd, xcount = xxcount, xtmp; \
+   int xdata1, xdata2; \
+__asm__ __volatile__( \
+        "subs %[count], #2                 \n\t" \
+        "ble 2f                            \n\t" \
+        "ldrd r4, [%[block], #0]           \n\t" \
+        "1:                                \n\t" \
+        "ldrd r6, [%[block], #8]           \n\t" \
+\
+        "rsbs %[data1], %[zero], r4, asr #16 \n\t" \
+        "addgt %[data1], %[qadd], #0       \n\t" \
+        "rsblt %[data1], %[qadd], #0       \n\t" \
+        "smlatbne %[data1], r4, %[qmul], %[data1] \n\t" \
+\
+        "rsbs %[data2], %[zero], r5, asr #16 \n\t" \
+        "addgt %[data2], %[qadd], #0       \n\t" \
+        "rsblt %[data2], %[qadd], #0       \n\t" \
+        "smlatbne %[data2], r5, %[qmul], %[data2] \n\t" \
+\
+        "rsbs %[tmp], %[zero], r4, asl #16 \n\t" \
+        "addgt %[tmp], %[qadd], #0         \n\t" \
+        "rsblt %[tmp], %[qadd], #0         \n\t" \
+        "smlabbne r4, r4, %[qmul], %[tmp]  \n\t" \
+\
+        "rsbs %[tmp], %[zero], r5, asl #16 \n\t" \
+        "addgt %[tmp], %[qadd], #0         \n\t" \
+        "rsblt %[tmp], %[qadd], #0         \n\t" \
+        "smlabbne r5, r5, %[qmul], %[tmp]  \n\t" \
+\
+        "strh r4, [%[block]], #2           \n\t" \
+        "strh %[data1], [%[block]], #2     \n\t" \
+        "strh r5, [%[block]], #2           \n\t" \
+        "strh %[data2], [%[block]], #2     \n\t" \
+\
+        "rsbs %[data1], %[zero], r6, asr #16 \n\t" \
+        "addgt %[data1], %[qadd], #0        \n\t" \
+        "rsblt %[data1], %[qadd], #0        \n\t" \
+        "smlatbne %[data1], r6, %[qmul], %[data1] \n\t" \
+\
+        "rsbs %[data2], %[zero], r7, asr #16 \n\t" \
+        "addgt %[data2], %[qadd], #0        \n\t" \
+        "rsblt %[data2], %[qadd], #0        \n\t" \
+        "smlatbne %[data2], r7, %[qmul], %[data2] \n\t" \
+\
+        "rsbs %[tmp], %[zero], r6, asl #16  \n\t" \
+        "addgt %[tmp], %[qadd], #0          \n\t" \
+        "rsblt %[tmp], %[qadd], #0          \n\t" \
+        "smlabbne r6, r6, %[qmul], %[tmp]   \n\t" \
+\
+        "rsbs %[tmp], %[zero], r7, asl #16  \n\t" \
+        "addgt %[tmp], %[qadd], #0          \n\t" \
+        "rsblt %[tmp], %[qadd], #0          \n\t" \
+        "smlabbne r7, r7, %[qmul], %[tmp]   \n\t" \
+\
+        "strh r6, [%[block]], #2            \n\t" \
+        "strh %[data1], [%[block]], #2      \n\t" \
+        "strh r7, [%[block]], #2            \n\t" \
+        "strh %[data2], [%[block]], #2      \n\t" \
+\
+        "subs %[count], #8                  \n\t" \
+        "ldrgtd r4, [%[block], #0]          \n\t" /* load data early to avoid load/use pipeline stall */ \
+        "bgt 1b                             \n\t" \
+\
+        "adds %[count], #2                  \n\t" \
+        "ble  3f                            \n\t" \
+        "2:                                 \n\t" \
+        "ldrsh %[data1], [%[block], #0]     \n\t" \
+        "ldrsh %[data2], [%[block], #2]     \n\t" \
+        "mov  %[tmp], %[qadd]               \n\t" \
+        "cmp  %[data1], #0                  \n\t" \
+        "rsblt %[tmp], %[qadd], #0          \n\t" \
+        "smlabbne %[data1], %[data1], %[qmul], %[tmp] \n\t" \
+        "mov  %[tmp], %[qadd]               \n\t" \
+        "cmp  %[data2], #0                  \n\t" \
+        "rsblt %[tmp], %[qadd], #0          \n\t" \
+        "smlabbne %[data2], %[data2], %[qmul], %[tmp] \n\t" \
+        "strh %[data1], [%[block]], #2      \n\t" \
+        "strh %[data2], [%[block]], #2      \n\t" \
+        "3:                                 \n\t" \
+        : [block] "+&r" (xblock), [count] "+&r" (xcount), [tmp] "=&r" (xtmp), \
+          [data1] "=&r" (xdata1), [data2] "=&r" (xdata2)  \
+        : [qmul] "r" (xqmul), [qadd] "r" (xqadd), [zero] "r" (0) \
+        : "r4", "r5", "r6", "r7", "cc", "memory" \
+); \
+})
+
+static void dct_unquantize_h263_intra_armv5te(MpegEncContext *s,
+                                  DCTELEM *block, int n, int qscale)
+{
+    int i, level, qmul, qadd;
+    int nCoeffs;
+
+    assert(s->block_last_index[n]>=0);
+
+    qmul = qscale << 1;
+
+    if (!s->h263_aic) {
+        if (n < 4)
+            level = block[0] * s->y_dc_scale;
+        else
+            level = block[0] * s->c_dc_scale;
+        qadd = (qscale - 1) | 1;
+    }else{
+        qadd = 0;
+        level = block[0];
+    }
+    if(s->ac_pred)
+        nCoeffs=63;
+    else
+        nCoeffs= s->inter_scantable.raster_end[ s->block_last_index[n] ];
+
+    dct_unquantize_h263_special_helper_armv5te(block, qmul, qadd, nCoeffs + 1);
+    block[0] = level;
+}
+
+static void dct_unquantize_h263_inter_armv5te(MpegEncContext *s,
+                                  DCTELEM *block, int n, int qscale)
+{
+    int i, level, qmul, qadd;
+    int nCoeffs;
+
+    assert(s->block_last_index[n]>=0);
+
+    qadd = (qscale - 1) | 1;
+    qmul = qscale << 1;
+
+    nCoeffs= s->inter_scantable.raster_end[ s->block_last_index[n] ];
+
+    dct_unquantize_h263_special_helper_armv5te(block, qmul, qadd, nCoeffs + 1);
+}
+
+#define HAVE_DCT_UNQUANTIZE_H263_ARMV5TE_OPTIMIZED
+
+#endif
+
+void MPV_common_init_armv5te(MpegEncContext *s)
+{
+#ifdef HAVE_DCT_UNQUANTIZE_H263_ARMV5TE_OPTIMIZED
+    s->dct_unquantize_h263_intra = dct_unquantize_h263_intra_armv5te;
+    s->dct_unquantize_h263_inter = dct_unquantize_h263_inter_armv5te;
+#endif
+}