Re-enable aarch64 neon instruction in vlib_buffer_free_inline

int vaddvq_u8 (uint8x16_t __a) is not appropriate to implement xxx_is_all_zero,
as there may be overflow causing incorrect return value.

Here's an example.
u8x16 x = {0 <repeats 12 times>, 1, 255, 0, 0};

Change-Id: Ia6a10bdf8da360dec12db902d028751a1a77e9a4
Signed-off-by: Lijian Zhang <Lijian.Zhang@arm.com>
Reviewed-by: Sirshak Das <Sirshak.Das@arm.com>

diff --git a/src/vlib/buffer_funcs.h b/src/vlib/buffer_funcs.h
index f2ac0bd..e7fd612 100644 (file)
--- a/src/vlib/buffer_funcs.h
+++ b/src/vlib/buffer_funcs.h
@@ -712,7 +712,7 @@ vlib_buffer_free_inline (vlib_main_t * vm, u32 * buffers, u32 n_buffers,
   u8 buffer_pool_index = ~0;
   u32 n_queue = 0, queue[queue_size + 4];
   vlib_buffer_t bt = { };
-#if defined(CLIB_HAVE_VEC128) && !__aarch64__
+#if defined(CLIB_HAVE_VEC128)
   vlib_buffer_t bpi_mask = {.buffer_pool_index = ~0 };
   vlib_buffer_t bpi_vec = {.buffer_pool_index = ~0 };
   vlib_buffer_t flags_refs_mask = {
@@ -737,7 +737,7 @@ vlib_buffer_free_inline (vlib_main_t * vm, u32 * buffers, u32 n_buffers,
       vlib_prefetch_buffer_header (b[6], LOAD);
       vlib_prefetch_buffer_header (b[7], LOAD);
 
-#if defined(CLIB_HAVE_VEC128) && !__aarch64__
+#if defined(CLIB_HAVE_VEC128)
       u8x16 p0, p1, p2, p3, r;
       p0 = u8x16_load_unaligned (b[0]);
       p1 = u8x16_load_unaligned (b[1]);
@@ -815,7 +815,7 @@ vlib_buffer_free_inline (vlib_main_t * vm, u32 * buffers, u32 n_buffers,
            }
 
          buffer_pool_index = b[0]->buffer_pool_index;
-#if defined(CLIB_HAVE_VEC128) && !__aarch64__
+#if defined(CLIB_HAVE_VEC128)
          bpi_vec.buffer_pool_index = buffer_pool_index;
 #endif
          bp = vlib_get_buffer_pool (vm, buffer_pool_index);

diff --git a/src/vppinfra/vector_neon.h b/src/vppinfra/vector_neon.h
index aef8365..9045160 100644 (file)
--- a/src/vppinfra/vector_neon.h
+++ b/src/vppinfra/vector_neon.h
@@ -22,6 +22,13 @@
 #define i16x8_sub_saturate(a,b) vsubq_s16(a,b)
 /* Dummy. Aid making uniform macros */
 #define vreinterpretq_u8_u8(a)  a
+/* Implement the missing intrinsics to make uniform macros */
+#define vminvq_u64(x)   \
+({  \
+  u64 x0 = vgetq_lane_u64(x, 0);    \
+  u64 x1 = vgetq_lane_u64(x, 1);    \
+  x0 < x1 ? x0 : x1;    \
+})
 
 /* Converts all ones/zeros compare mask to bitmap. */
 always_inline u32
@@ -62,11 +69,11 @@ t##s##x##c##_store_unaligned (t##s##x##c v, void *p)                        \
 \
 static_always_inline int                                               \
 t##s##x##c##_is_all_zero (t##s##x##c x)                                        \
-{ return !(vaddvq_##i (x)); }                                          \
+{ return !!(vminvq_u##s (vceqq_##i (vdupq_n_##i(0), x))); }                                            \
 \
 static_always_inline int                                               \
 t##s##x##c##_is_equal (t##s##x##c a, t##s##x##c b)                     \
-{ return t##s##x##c##_is_all_zero (a ^ b); }                           \
+{ return !!(vminvq_u##s (vceqq_##i (a, b))); }                         \
 \
 static_always_inline int                                               \
 t##s##x##c##_is_all_equal (t##s##x##c v, t##s x)                       \