x86: Add asm for mbtree fixed point conversion

[x264] / common / cpu.h

diff --git a/common/cpu.h b/common/cpu.h
index 5438f920ae29238582e98ab5be63381e275afb62..138141946fc4ff6929a5aa7eed29bb95643478be 100644 (file)
--- a/common/cpu.h
+++ b/common/cpu.h
@@ -1,7 +1,7 @@
 /*****************************************************************************
  * cpu.h: cpu detection
  *****************************************************************************
- * Copyright (C) 2004-2011 x264 project
+ * Copyright (C) 2004-2016 x264 project
  *
  * Authors: Loren Merritt <lorenm@u.washington.edu>
  *
@@ -31,23 +31,33 @@ int      x264_cpu_num_processors( void );
 void     x264_cpu_emms( void );
 void     x264_cpu_sfence( void );
 #if HAVE_MMX
+/* There is no way to forbid the compiler from using float instructions
+ * before the emms so miscompilation could theoretically occur in the
+ * unlikely event that the compiler reorders emms and float instructions. */
+#if HAVE_X86_INLINE_ASM
+/* Clobbering memory makes the compiler less likely to reorder code. */
+#define x264_emms() asm volatile( "emms":::"memory","st","st(1)","st(2)", \
+                                  "st(3)","st(4)","st(5)","st(6)","st(7)" )
+#else
 #define x264_emms() x264_cpu_emms()
+#endif
 #else
 #define x264_emms()
 #endif
 #define x264_sfence x264_cpu_sfence
-void     x264_cpu_mask_misalign_sse( void );
 
-/* kluge:
+/* kludge:
  * gcc can't give variables any greater alignment than the stack frame has.
- * We need 16 byte alignment for SSE2, so here we make sure that the stack is
- * aligned to 16 bytes.
+ * We need 32 byte alignment for AVX2, so here we make sure that the stack is
+ * aligned to 32 bytes.
  * gcc 4.2 introduced __attribute__((force_align_arg_pointer)) to fix this
  * problem, but I don't want to require such a new version.
- * This applies only to x86_32, since other architectures that need alignment
- * either have ABIs that ensure aligned stack, or don't support it at all. */
-#if ARCH_X86 && HAVE_MMX
-int x264_stack_align( void (*func)(), ... );
+ * aligning to 32 bytes only works if the compiler supports keeping that
+ * alignment between functions (osdep.h handles manual alignment of arrays
+ * if it doesn't).
+ */
+#if (ARCH_X86 || STACK_ALIGNMENT > 16) && HAVE_MMX
+intptr_t x264_stack_align( void (*func)(), ... );
 #define x264_stack_align(func,...) x264_stack_align((void (*)())func, __VA_ARGS__)
 #else
 #define x264_stack_align(func,...) func(__VA_ARGS__)
@@ -56,7 +66,7 @@ int x264_stack_align( void (*func)(), ... );
 typedef struct
 {
     const char name[16];
-    int flags;
+    uint32_t flags;
 } x264_cpu_name_t;
 extern const x264_cpu_name_t x264_cpu_names[];