Eliminate unused C DSP functions at compile time

When compiling with asm enabled there's no point in compiling
C versions of DSP functions that have asm implementations using
instruction sets that the compiler can unconditionally use.

E.g. when compiling with -mssse3 we can remove the C version
of all functions with SSSE3 implementations.

This is accomplished using the compiler's dead code elimination
functionality.

Can be configured using the new 'trim_dsp' meson option, which
by default is enabled when compiling in release mode.

4 files changed, 127 insertions, 55 deletions

diff --git a/src/ppc/cdef.h b/src/ppc/cdef.h
new file mode 100644
index 0000000..b794ba5
--- /dev/null
+++ b/src/ppc/cdef.h
@@ -0,0 +1,61 @@
+/*
+ * Copyright © 2019, Luca Barbato
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stdlib.h>
+
+#include "common/bitdepth.h"
+#include "common/intops.h"
+
+#include "src/cdef.h"
+#include "src/cpu.h"
+
+#define cdef_vsx_fn(w, h) \
+void dav1d_cdef_filter_##w##x##h##_vsx(pixel *const dst, \
+                                       const ptrdiff_t dst_stride, \
+                                       const pixel (*left)[2], \
+                                       const pixel *const top, \
+                                       const pixel *const bottom, \
+                                       const int pri_strength, \
+                                       const int sec_strength, \
+                                       const int dir, \
+                                       const int damping, \
+                                       const enum CdefEdgeFlags edges)
+
+cdef_vsx_fn(4, 4);
+cdef_vsx_fn(4, 8);
+cdef_vsx_fn(8, 8);
+
+static ALWAYS_INLINE void cdef_dsp_init_ppc(Dav1dCdefDSPContext *const c) {
+    const unsigned flags = dav1d_get_cpu_flags();
+
+    if (!(flags & DAV1D_PPC_CPU_FLAG_VSX)) return;
+
+#if BITDEPTH == 8
+    c->fb[0] = dav1d_cdef_filter_8x8_vsx;
+    c->fb[1] = dav1d_cdef_filter_4x8_vsx;
+    c->fb[2] = dav1d_cdef_filter_4x4_vsx;
+#endif
+}
diff --git a/src/ppc/cdef_init_tmpl.c b/src/ppc/cdef_tmpl.c
index 12e4a66..020e17b 100644
--- a/src/ppc/cdef_init_tmpl.c
+++ b/src/ppc/cdef_tmpl.c
@@ -24,15 +24,8 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include <stdlib.h>
-
-#include "common/bitdepth.h"
-#include "common/intops.h"
-
-#include "src/cdef.h"
-#include "src/cpu.h"
-
 #include "src/ppc/dav1d_types.h"
+#include "src/ppc/cdef.h"
 
 #if BITDEPTH == 8
 static inline i16x8 vconstrain(const i16x8 diff, const int16_t threshold,
@@ -451,18 +444,17 @@ filter_8xN(pixel *dst, const ptrdiff_t dst_stride,
 
 }
 
-
 #define cdef_fn(w, h, tmp_stride) \
-static void cdef_filter_##w##x##h##_vsx(pixel *const dst, \
-                                        const ptrdiff_t dst_stride, \
-                                        const pixel (*left)[2], \
-                                        const pixel *const top, \
-                                        const pixel *const bottom, \
-                                        const int pri_strength, \
-                                        const int sec_strength, \
-                                        const int dir, \
-                                        const int damping, \
-                                        const enum CdefEdgeFlags edges) \
+void dav1d_cdef_filter_##w##x##h##_vsx(pixel *const dst, \
+                                       const ptrdiff_t dst_stride, \
+                                       const pixel (*left)[2], \
+                                       const pixel *const top, \
+                                       const pixel *const bottom, \
+                                       const int pri_strength, \
+                                       const int sec_strength, \
+                                       const int dir, \
+                                       const int damping, \
+                                       const enum CdefEdgeFlags edges) \
 { \
     ALIGN_STK_16(uint16_t, tmp_buf, 12 * tmp_stride,); \
     uint16_t *tmp = tmp_buf + 2 * tmp_stride + 2; \
@@ -474,16 +466,3 @@ cdef_fn(4, 4, 8);
 cdef_fn(4, 8, 8);
 cdef_fn(8, 8, 16);
 #endif
-
-COLD void bitfn(dav1d_cdef_dsp_init_ppc)(Dav1dCdefDSPContext *const c) {
-    const unsigned flags = dav1d_get_cpu_flags();
-
-    if (!(flags & DAV1D_PPC_CPU_FLAG_VSX)) return;
-
-#if BITDEPTH == 8
-    // c->dir = dav1d_cdef_find_dir_vsx;
-    c->fb[0] = cdef_filter_8x8_vsx;
-    c->fb[1] = cdef_filter_4x8_vsx;
-    c->fb[2] = cdef_filter_4x4_vsx;
-#endif
-}
diff --git a/src/ppc/looprestoration.h b/src/ppc/looprestoration.h
new file mode 100644
index 0000000..3fe1631
--- /dev/null
+++ b/src/ppc/looprestoration.h
@@ -0,0 +1,48 @@
+/*
+ * Copyright © 2019, VideoLAN and dav1d authors
+ * Copyright © 2019, Michail Alvanos
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "common/intops.h"
+
+#include "src/cpu.h"
+#include "src/looprestoration.h"
+
+void dav1d_wiener_filter_vsx(uint8_t *p, const ptrdiff_t stride,
+                             const uint8_t (*const left)[4],
+                             const uint8_t *lpf,
+                             const int w, const int h,
+                             const LooprestorationParams *const params,
+                             const enum LrEdgeFlags edges HIGHBD_DECL_SUFFIX);
+
+static ALWAYS_INLINE void loop_restoration_dsp_init_ppc(Dav1dLoopRestorationDSPContext *const c, const int bpc) {
+    const unsigned flags = dav1d_get_cpu_flags();
+
+    if (!(flags & DAV1D_PPC_CPU_FLAG_VSX)) return;
+
+#if BITDEPTH == 8
+    c->wiener[0] = c->wiener[1] = dav1d_wiener_filter_vsx;
+#endif
+}
diff --git a/src/ppc/looprestoration_init_tmpl.c b/src/ppc/looprestoration_tmpl.c
index e9bc622..f64a963 100644
--- a/src/ppc/looprestoration_init_tmpl.c
+++ b/src/ppc/looprestoration_tmpl.c
@@ -25,10 +25,8 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include "common/intops.h"
 #include "src/ppc/dav1d_types.h"
-#include "src/cpu.h"
-#include "src/looprestoration.h"
+#include "src/ppc/looprestoration.h"
 
 #if BITDEPTH == 8
 
@@ -302,12 +300,12 @@ static inline void padding(uint8_t *dst, const uint8_t *p,
 // (since first and last tops are always 0 for chroma)
 // FIXME Could implement a version that requires less temporary memory
 // (should be possible to implement with only 6 rows of temp storage)
-static void wiener_filter_vsx(uint8_t *p, const ptrdiff_t stride,
-                              const uint8_t (*const left)[4],
-                              const uint8_t *lpf,
-                              const int w, const int h,
-                              const LooprestorationParams *const params,
-                              const enum LrEdgeFlags edges HIGHBD_DECL_SUFFIX)
+void dav1d_wiener_filter_vsx(uint8_t *p, const ptrdiff_t stride,
+                             const uint8_t (*const left)[4],
+                             const uint8_t *lpf,
+                             const int w, const int h,
+                             const LooprestorationParams *const params,
+                             const enum LrEdgeFlags edges HIGHBD_DECL_SUFFIX)
 {
     const int16_t (*const filter)[8] = params->filter;
 
@@ -321,17 +319,3 @@ static void wiener_filter_vsx(uint8_t *p, const ptrdiff_t stride,
     wiener_filter_v_vsx(p, stride, hor, filter[1], w, h);
 }
 #endif
-
-COLD void bitfn(dav1d_loop_restoration_dsp_init_ppc)(Dav1dLoopRestorationDSPContext *const c,
-                                                     const int bpc)
-{
-    const unsigned flags = dav1d_get_cpu_flags();
-
-    if (!(flags & DAV1D_PPC_CPU_FLAG_VSX)) return;
-
-#if BITDEPTH == 8
-    c->wiener[0] = c->wiener[1] = wiener_filter_vsx;
-#endif
-}
-
-