svm: march svm_fifo take 2

Change-Id: Ifa4fceef7edbe43d444790a624957db0817064de
Signed-off-by: Florin Coras <fcoras@cisco.com>

2 files changed, 46 insertions, 71 deletions

diff --git a/src/svm/svm_fifo.c b/src/svm/svm_fifo.c
index 6a9c0df676f..ac368dddb2c 100644
--- a/src/svm/svm_fifo.c
+++ b/src/svm/svm_fifo.c
@@ -16,41 +16,6 @@
 #include <svm/svm_fifo.h>
 #include <vppinfra/cpu.h>
 
-#if __x86_64__ && CLIB_DEBUG == 0
-#define foreach_march_variant_runtime(macro, _args...) 			\
-  macro(avx512, avx512f, _args)						\
-  macro(avx2, avx2, _args)
-#else
-#define foreach_march_variant_runtime(macro, _args...)
-#endif
-
-#define CLIB_MARCH_ARCH_CHECK(arch, archname, fn)			\
-  if (clib_cpu_supports_ ## archname ())				\
-    return & fn ## _ ##arch;
-
-#define CLIB_MARCH_SELECT_FN(fn,...)                               	\
-  __VA_ARGS__ void * fn ## _multiarch_select(void)                     	\
-{                                                                      	\
-  foreach_march_variant_runtime(CLIB_MARCH_ARCH_CHECK, fn)              \
-  return & fn;                                                         	\
-}
-
-#define DEFINE_WEAK_FN(_arch, _fn, _args...) 				\
-  int __attribute__((weak)) _fn##_ma_##_arch(_args);
-#define DEFINE_FN_HELPER(arch, archname, macro, _args...)		\
-  macro(arch, _args)
-
-#ifndef CLIB_MARCH_VARIANT
-#define MARCH_FN(fn, _args...)						\
-  static void * (*fn ## _selected) (void);				\
-  foreach_march_variant_runtime (DEFINE_FN_HELPER, DEFINE_WEAK_FN, fn,	\
-				  _args);				\
-  static inline int CLIB_CPU_OPTIMIZED CLIB_MARCH_SFX (fn ## _ma)(_args)
-#else
-#define MARCH_FN(fn, _args...)						\
- int CLIB_CPU_OPTIMIZED CLIB_MARCH_SFX (fn ## _ma)(_args)
-#endif
-
 static inline u8
 position_lt (svm_fifo_t * f, u32 a, u32 b)
 {
@@ -489,8 +454,8 @@ ooo_segment_try_collect (svm_fifo_t * f, u32 n_bytes_enqueued)
   return bytes;
 }
 
-MARCH_FN (svm_fifo_enqueue_nowait, svm_fifo_t * f, u32 max_bytes,
-	  const u8 * copy_from_here)
+CLIB_MARCH_FN (svm_fifo_enqueue_nowait, int, svm_fifo_t * f, u32 max_bytes,
+	       const u8 * copy_from_here)
 {
   u32 total_copy_bytes, first_copy_bytes, second_copy_bytes;
   u32 cursize, nitems;
@@ -557,8 +522,8 @@ int
 svm_fifo_enqueue_nowait (svm_fifo_t * f, u32 max_bytes,
 			 const u8 * copy_from_here)
 {
-  return ((int (*)(svm_fifo_t * f, u32, const u8 *))
-	  (*svm_fifo_enqueue_nowait_selected)) (f, max_bytes, copy_from_here);
+  return CLIB_MARCH_FN_SELECT (svm_fifo_enqueue_nowait) (f, max_bytes,
+							 copy_from_here);
 }
 #endif
 
@@ -569,8 +534,8 @@ svm_fifo_enqueue_nowait (svm_fifo_t * f, u32 max_bytes,
  * Returns 0 of the entire segment was copied
  * Returns -1 if none of the segment was copied due to lack of space
  */
-MARCH_FN (svm_fifo_enqueue_with_offset, svm_fifo_t * f,
-	  u32 offset, u32 required_bytes, u8 * copy_from_here)
+CLIB_MARCH_FN (svm_fifo_enqueue_with_offset, int, svm_fifo_t * f,
+	       u32 offset, u32 required_bytes, u8 * copy_from_here)
 {
   u32 total_copy_bytes, first_copy_bytes, second_copy_bytes;
   u32 cursize, nitems, normalized_offset;
@@ -624,10 +589,9 @@ int
 svm_fifo_enqueue_with_offset (svm_fifo_t * f, u32 offset, u32 required_bytes,
 			      u8 * copy_from_here)
 {
-  return ((int (*)(svm_fifo_t * f, u32, u32, u8 *))
-	  (*svm_fifo_enqueue_with_offset_selected)) (f, offset,
-						     required_bytes,
-						     copy_from_here);
+  return CLIB_MARCH_FN_SELECT (svm_fifo_enqueue_with_offset) (f, offset,
+							      required_bytes,
+							      copy_from_here);
 }
 
 void
@@ -646,8 +610,8 @@ svm_fifo_overwrite_head (svm_fifo_t * f, u8 * data, u32 len)
 }
 #endif
 
-MARCH_FN (svm_fifo_dequeue_nowait, svm_fifo_t * f, u32 max_bytes,
-	  u8 * copy_here)
+CLIB_MARCH_FN (svm_fifo_dequeue_nowait, int, svm_fifo_t * f, u32 max_bytes,
+	       u8 * copy_here)
 {
   u32 total_copy_bytes, first_copy_bytes, second_copy_bytes;
   u32 cursize, nitems;
@@ -704,13 +668,13 @@ MARCH_FN (svm_fifo_dequeue_nowait, svm_fifo_t * f, u32 max_bytes,
 int
 svm_fifo_dequeue_nowait (svm_fifo_t * f, u32 max_bytes, u8 * copy_here)
 {
-  return ((int (*)(svm_fifo_t * f, u32, u8 *))
-	  (*svm_fifo_dequeue_nowait_selected)) (f, max_bytes, copy_here);
+  return CLIB_MARCH_FN_SELECT (svm_fifo_dequeue_nowait) (f, max_bytes,
+							 copy_here);
 }
 #endif
 
-MARCH_FN (svm_fifo_peek, svm_fifo_t * f, u32 relative_offset, u32 max_bytes,
-	  u8 * copy_here)
+CLIB_MARCH_FN (svm_fifo_peek, int, svm_fifo_t * f, u32 relative_offset,
+	       u32 max_bytes, u8 * copy_here)
 {
   u32 total_copy_bytes, first_copy_bytes, second_copy_bytes;
   u32 cursize, nitems, real_head;
@@ -753,9 +717,8 @@ int
 svm_fifo_peek (svm_fifo_t * f, u32 relative_offset, u32 max_bytes,
 	       u8 * copy_here)
 {
-  return ((int (*)(svm_fifo_t * f, u32, u32, u8 *))
-	  (*svm_fifo_peek_selected)) (f, relative_offset, max_bytes,
-				      copy_here);
+  return CLIB_MARCH_FN_SELECT (svm_fifo_peek) (f, relative_offset, max_bytes,
+					       copy_here);
 }
 
 int
@@ -873,23 +836,6 @@ svm_fifo_init_pointers (svm_fifo_t * f, u32 pointer)
   f->head = f->tail = pointer % f->nitems;
 }
 
-#define foreach_svm_fifo_march_fn					\
-  _(svm_fifo_enqueue_nowait)						\
-  _(svm_fifo_enqueue_with_offset)					\
-  _(svm_fifo_dequeue_nowait)						\
-  _(svm_fifo_peek)							\
-
-#define _(_fn, _args...) CLIB_MARCH_SELECT_FN(_fn ## _ma);
-foreach_svm_fifo_march_fn
-#undef _
-void __clib_constructor
-svm_fifo_select_march_fns (void)
-{
-#define _(_fn, _args...) _fn ## _selected = _fn ## _ma_multiarch_select ();
-  foreach_svm_fifo_march_fn
-#undef _
-}
-
 #endif
 /*
  * fd.io coding-style-patch-verification: ON
diff --git a/src/vppinfra/cpu.h b/src/vppinfra/cpu.h
index 110815c9f87..c636cf8639c 100644
--- a/src/vppinfra/cpu.h
+++ b/src/vppinfra/cpu.h
@@ -190,6 +190,35 @@ clib_cpu_march_priority_avx2 ()
 #endif
 #endif /* included_clib_cpu_h */
 
+#define CLIB_MARCH_FN_CONSTRUCTOR(fn)					\
+static void __clib_constructor 						\
+CLIB_MARCH_SFX(fn ## _march_constructor) (void)				\
+{									\
+  if (CLIB_MARCH_FN_PRIORITY() > fn ## _selected_priority)		\
+    {									\
+      fn ## _selected = & CLIB_MARCH_SFX (fn ## _ma);			\
+      fn ## _selected_priority = CLIB_MARCH_FN_PRIORITY();		\
+    }									\
+}									\
+
+#ifndef CLIB_MARCH_VARIANT
+#define CLIB_MARCH_FN(fn, rtype, _args...)				\
+  static rtype CLIB_CPU_OPTIMIZED CLIB_MARCH_SFX (fn ## _ma)(_args);	\
+  rtype (*fn ## _selected) (_args) = & CLIB_MARCH_SFX (fn ## _ma);	\
+  int fn ## _selected_priority = 0;					\
+  static inline rtype CLIB_CPU_OPTIMIZED 				\
+  CLIB_MARCH_SFX (fn ## _ma)(_args)
+#else
+#define CLIB_MARCH_FN(fn, rtype, _args...)				\
+  static rtype CLIB_CPU_OPTIMIZED CLIB_MARCH_SFX (fn ## _ma)(_args);	\
+  extern int (*fn ## _selected) (_args);				\
+  extern int fn ## _selected_priority;					\
+  CLIB_MARCH_FN_CONSTRUCTOR (fn)					\
+  static rtype CLIB_CPU_OPTIMIZED CLIB_MARCH_SFX (fn ## _ma)(_args)
+#endif
+
+#define CLIB_MARCH_FN_SELECT(fn) (* fn ## _selected)
+
 format_function_t format_cpu_uarch;
 format_function_t format_cpu_model_name;
 format_function_t format_cpu_flags;