dsputil: Split clear_block*/fill_block* off into a separate context

1 files changed, 169 insertions, 0 deletions

diff --git a/libavcodec/ppc/blockdsp.c b/libavcodec/ppc/blockdsp.c
new file mode 100644
index 0000000000..679bc0454f
--- /dev/null
+++ b/libavcodec/ppc/blockdsp.c
@@ -0,0 +1,169 @@
+/*
+ * Copyright (c) 2002 Brian Foley
+ * Copyright (c) 2002 Dieter Shirley
+ * Copyright (c) 2003-2004 Romain Dolbeau <romain@dolbeau.org>
+ *
+ * This file is part of Libav.
+ *
+ * Libav 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.
+ *
+ * Libav 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 Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "config.h"
+#if HAVE_ALTIVEC_H
+#include <altivec.h>
+#endif
+#include <string.h>
+
+#include "libavutil/attributes.h"
+#include "libavutil/cpu.h"
+#include "libavutil/mem.h"
+#include "libavutil/ppc/cpu.h"
+#include "libavutil/ppc/types_altivec.h"
+#include "libavcodec/blockdsp.h"
+
+/* ***** WARNING ***** WARNING ***** WARNING ***** */
+/*
+ * clear_blocks_dcbz32_ppc will not work properly on PowerPC processors with
+ * a cache line size not equal to 32 bytes. Fortunately all processors used
+ * by Apple up to at least the 7450 (AKA second generation G4) use 32-byte
+ * cache lines. This is due to the use of the 'dcbz' instruction. It simply
+ * clears a single cache line to zero, so you need to know the cache line
+ * size to use it! It's absurd, but it's fast...
+ *
+ * update 24/06/2003: Apple released the G5 yesterday, with a PPC970.
+ * cache line size: 128 bytes. Oups.
+ * The semantics of dcbz was changed, it always clears 32 bytes. So the function
+ * below will work, but will be slow. So I fixed check_dcbz_effect to use dcbzl,
+ * which is defined to clear a cache line (as dcbz before). So we can still
+ * distinguish, and use dcbz (32 bytes) or dcbzl (one cache line) as required.
+ *
+ * see <http://developer.apple.com/technotes/tn/tn2087.html>
+ * and <http://developer.apple.com/technotes/tn/tn2086.html>
+ */
+static void clear_blocks_dcbz32_ppc(int16_t *blocks)
+{
+    register int misal = (unsigned long) blocks & 0x00000010, i = 0;
+
+    if (misal) {
+        ((unsigned long *) blocks)[0] = 0L;
+        ((unsigned long *) blocks)[1] = 0L;
+        ((unsigned long *) blocks)[2] = 0L;
+        ((unsigned long *) blocks)[3] = 0L;
+        i += 16;
+    }
+    for (; i < sizeof(int16_t) * 6 * 64 - 31; i += 32)
+        __asm__ volatile ("dcbz %0,%1" :: "b" (blocks), "r" (i) : "memory");
+    if (misal) {
+        ((unsigned long *) blocks)[188] = 0L;
+        ((unsigned long *) blocks)[189] = 0L;
+        ((unsigned long *) blocks)[190] = 0L;
+        ((unsigned long *) blocks)[191] = 0L;
+        i += 16;
+    }
+}
+
+/* Same as above, when dcbzl clears a whole 128 bytes cache line
+ * i.e. the PPC970 AKA G5. */
+static void clear_blocks_dcbz128_ppc(int16_t *blocks)
+{
+#if HAVE_DCBZL
+    register int misal = (unsigned long) blocks & 0x0000007f, i = 0;
+
+    if (misal) {
+        /* We could probably also optimize this case,
+         * but there's not much point as the machines
+         * aren't available yet (2003-06-26). */
+        memset(blocks, 0, sizeof(int16_t) * 6 * 64);
+    } else {
+        for (; i < sizeof(int16_t) * 6 * 64; i += 128)
+            __asm__ volatile ("dcbzl %0,%1" :: "b" (blocks), "r" (i) : "memory");
+    }
+#else
+    memset(blocks, 0, sizeof(int16_t) * 6 * 64);
+#endif
+}
+
+/* Check dcbz report how many bytes are set to 0 by dcbz. */
+/* update 24/06/2003: Replace dcbz by dcbzl to get the intended effect
+ * (Apple "fixed" dcbz). Unfortunately this cannot be used unless the
+ * assembler knows about dcbzl ... */
+static long check_dcbzl_effect(void)
+{
+    long count = 0;
+#if HAVE_DCBZL
+    register char *fakedata = av_malloc(1024);
+    register char *fakedata_middle;
+    register long zero = 0, i = 0;
+
+    if (!fakedata)
+        return 0L;
+
+    fakedata_middle = fakedata + 512;
+
+    memset(fakedata, 0xFF, 1024);
+
+    /* Below the constraint "b" seems to mean "address base register"
+     * in gcc-3.3 / RS/6000 speaks. Seems to avoid using r0, so.... */
+    __asm__ volatile ("dcbzl %0, %1" :: "b" (fakedata_middle), "r" (zero));
+
+    for (i = 0; i < 1024; i++)
+        if (fakedata[i] == (char) 0)
+            count++;
+
+    av_free(fakedata);
+#endif
+
+    return count;
+}
+
+#if HAVE_ALTIVEC
+static void clear_block_altivec(int16_t *block)
+{
+    LOAD_ZERO;
+    vec_st(zero_s16v,   0, block);
+    vec_st(zero_s16v,  16, block);
+    vec_st(zero_s16v,  32, block);
+    vec_st(zero_s16v,  48, block);
+    vec_st(zero_s16v,  64, block);
+    vec_st(zero_s16v,  80, block);
+    vec_st(zero_s16v,  96, block);
+    vec_st(zero_s16v, 112, block);
+}
+#endif /* HAVE_ALTIVEC */
+
+av_cold void ff_blockdsp_init_ppc(BlockDSPContext *c, unsigned high_bit_depth)
+{
+    // common optimizations whether AltiVec is available or not
+    if (!high_bit_depth) {
+        switch (check_dcbzl_effect()) {
+        case 32:
+            c->clear_blocks = clear_blocks_dcbz32_ppc;
+            break;
+        case 128:
+            c->clear_blocks = clear_blocks_dcbz128_ppc;
+            break;
+        default:
+            break;
+        }
+    }
+
+#if HAVE_ALTIVEC
+    if (!PPC_ALTIVEC(av_get_cpu_flags()))
+        return;
+
+    if (!high_bit_depth)
+        c->clear_block = clear_block_altivec;
+#endif /* HAVE_ALTIVEC */
+}