[FFmpeg-devel] [PATCH] Properly mark sse2 instructions in emulated_edge_mc x86 simd as such.

[Ronald S. Bultje]

Should fix crashes or corrupt output on pre-SSE2 CPUs when they were
using SSE2-code (e.g. AMD Athlon XP 2400+ or Intel Pentium III) in
hfix or hvar single-edge (left/right) extension functions.
---
 libavcodec/x86/videodsp.asm    | 12 ++++++------
 libavcodec/x86/videodsp_init.c | 42 ++++++++++++++++++++++++++----------------
 2 files changed, 32 insertions(+), 22 deletions(-)

diff --git a/libavcodec/x86/videodsp.asm b/libavcodec/x86/videodsp.asm
index aa865f5..6d5b57e 100644
--- a/libavcodec/x86/videodsp.asm
+++ b/libavcodec/x86/videodsp.asm
@@ -100,10 +100,10 @@ cglobal emu_edge_hvar, 5, 6, 1, dst, dst_stride, start_x, n_words, h, w
     ; FIXME also write a ssse3 version using pshufb
     movzx            wd, byte [dstq+start_xq]   ;   w = read(1)
     imul             wd, 0x01010101             ;   w *= 0x01010101
-    movd             m0, wd                     ;   FIXME this is sse2, not sse
+    movd             m0, wd
     mov              wq, n_wordsq               ;   initialize w
-%if cpuflag(sse)
-    shufps           m0, m0, q0000              ;   splat
+%if cpuflag(sse2)
+    pshufd           m0, m0, q0000              ;   splat
 %else ; mmx
     punpckldq        m0, m0                     ;   splat
 %endif ; mmx/sse
@@ -124,7 +124,7 @@ INIT_MMX mmx
 hvar_fn
 %endif
 
-INIT_XMM sse
+INIT_XMM sse2
 hvar_fn
 
 ; macro to read/write a horizontal number of pixels (%2) to/from registers
@@ -353,7 +353,7 @@ VERTICAL_EXTEND 16, 22
 %if %1 >= 8
     movd             m0, vald
 %if mmsize == 16
-    shufps           m0, m0, q0000
+    pshufd           m0, m0, q0000
 %else
     punpckldq        m0, m0
 %endif
@@ -423,7 +423,7 @@ H_EXTEND 2, 14
 H_EXTEND 16, 22
 %endif
 
-INIT_XMM sse
+INIT_XMM sse2
 H_EXTEND 16, 22
 
 %macro PREFETCH_FN 1
diff --git a/libavcodec/x86/videodsp_init.c b/libavcodec/x86/videodsp_init.c
index b5bab72..0e6e0dd 100644
--- a/libavcodec/x86/videodsp_init.c
+++ b/libavcodec/x86/videodsp_init.c
@@ -117,17 +117,17 @@ static emu_edge_hfix_func *hfixtbl_mmx[11] = {
 };
 #endif
 extern emu_edge_hvar_func ff_emu_edge_hvar_mmx;
-extern emu_edge_hfix_func ff_emu_edge_hfix16_sse;
-extern emu_edge_hfix_func ff_emu_edge_hfix18_sse;
-extern emu_edge_hfix_func ff_emu_edge_hfix20_sse;
-extern emu_edge_hfix_func ff_emu_edge_hfix22_sse;
-static emu_edge_hfix_func *hfixtbl_sse[11] = {
+extern emu_edge_hfix_func ff_emu_edge_hfix16_sse2;
+extern emu_edge_hfix_func ff_emu_edge_hfix18_sse2;
+extern emu_edge_hfix_func ff_emu_edge_hfix20_sse2;
+extern emu_edge_hfix_func ff_emu_edge_hfix22_sse2;
+static emu_edge_hfix_func *hfixtbl_sse2[11] = {
     ff_emu_edge_hfix2_mmx,  ff_emu_edge_hfix4_mmx,  ff_emu_edge_hfix6_mmx,
     ff_emu_edge_hfix8_mmx,  ff_emu_edge_hfix10_mmx, ff_emu_edge_hfix12_mmx,
-    ff_emu_edge_hfix14_mmx, ff_emu_edge_hfix16_sse, ff_emu_edge_hfix18_sse,
-    ff_emu_edge_hfix20_sse, ff_emu_edge_hfix22_sse
+    ff_emu_edge_hfix14_mmx, ff_emu_edge_hfix16_sse2, ff_emu_edge_hfix18_sse2,
+    ff_emu_edge_hfix20_sse2, ff_emu_edge_hfix22_sse2
 };
-extern emu_edge_hvar_func ff_emu_edge_hvar_sse;
+extern emu_edge_hvar_func ff_emu_edge_hvar_sse2;
 
 static av_always_inline void emulated_edge_mc(uint8_t *dst, ptrdiff_t dst_stride,
                                               const uint8_t *src, ptrdiff_t src_stride,
@@ -212,21 +212,26 @@ static av_noinline void emulated_edge_mc_mmx(uint8_t *buf, ptrdiff_t buf_stride,
                      src_x, src_y, w, h, vfixtbl_mmx, &ff_emu_edge_vvar_mmx,
                      hfixtbl_mmx, &ff_emu_edge_hvar_mmx);
 }
-#endif
 
 static av_noinline void emulated_edge_mc_sse(uint8_t *buf, ptrdiff_t buf_stride,
                                              const uint8_t *src, ptrdiff_t src_stride,
                                              int block_w, int block_h,
                                              int src_x, int src_y, int w, int h)
 {
-    emulated_edge_mc(buf, buf_stride, src, src_stride, block_w, block_h, src_x,
-                     src_y, w, h, vfixtbl_sse, &ff_emu_edge_vvar_sse, hfixtbl_sse,
-#if ARCH_X86_64
-                     &ff_emu_edge_hvar_sse
-#else
-                     &ff_emu_edge_hvar_mmx
+    emulated_edge_mc(buf, buf_stride, src, src_stride, block_w, block_h,
+                     src_x, src_y, w, h, vfixtbl_sse, &ff_emu_edge_vvar_sse,
+                     hfixtbl_mmx, &ff_emu_edge_hvar_mmx);
+}
 #endif
-                     );
+
+static av_noinline void emulated_edge_mc_sse2(uint8_t *buf, ptrdiff_t buf_stride,
+                                              const uint8_t *src, ptrdiff_t src_stride,
+                                              int block_w, int block_h,
+                                              int src_x, int src_y, int w, int h)
+{
+    emulated_edge_mc(buf, buf_stride, src, src_stride, block_w, block_h, src_x,
+                     src_y, w, h, vfixtbl_sse, &ff_emu_edge_vvar_sse,
+                     hfixtbl_sse2, &ff_emu_edge_hvar_sse2);
 }
 #endif /* HAVE_YASM */
 
@@ -249,8 +254,13 @@ av_cold void ff_videodsp_init_x86(VideoDSPContext *ctx, int bpc)
     if (EXTERNAL_MMXEXT(cpu_flags)) {
         ctx->prefetch = ff_prefetch_mmxext;
     }
+#if ARCH_X86_32
     if (EXTERNAL_SSE(cpu_flags) && bpc <= 8) {
         ctx->emulated_edge_mc = emulated_edge_mc_sse;
     }
+#endif /* ARCH_X86_32 */
+    if (EXTERNAL_SSE2(cpu_flags) && bpc <= 8) {
+        ctx->emulated_edge_mc = emulated_edge_mc_sse2;
+    }
 #endif /* HAVE_YASM */
 }
-- 
1.8.4