[PATCH v7 14/39] acl: use C11 alignas

[Tyler Retzlaff <roretzla@linux.microsoft.com>]

The current location used for __rte_aligned(a) for alignment of types
and variables is not compatible with MSVC. There is only a single
location accepted by both toolchains.

For variables standard C11 offers alignas(a) supported by conformant
compilers i.e. both MSVC and GCC.

For types the standard offers no alignment facility that compatibly
interoperates with C and C++ but may be achieved by relocating the
placement of __rte_aligned(a) to the aforementioned location accepted
by all currently supported toolchains.

To allow alignment for both compilers do the following:

* Move __rte_aligned from the end of {struct,union} definitions to
  be between {struct,union} and tag.

  The placement between {struct,union} and the tag allows the desired
  alignment to be imparted on the type regardless of the toolchain being
  used for all of GCC, LLVM, MSVC compilers building both C and C++.

* Replace use of __rte_aligned(a) on variables/fields with alignas(a).

Signed-off-by: Tyler Retzlaff <roretzla@linux.microsoft.com>
Acked-by: Morten Brørup <mb@smartsharesystems.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev@huawei.com>
---
 lib/acl/acl_run.h         | 4 ++--
 lib/acl/acl_run_altivec.h | 6 ++++--
 lib/acl/acl_run_neon.h    | 6 ++++--
 3 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/lib/acl/acl_run.h b/lib/acl/acl_run.h
index 7d215de..7f09241 100644
--- a/lib/acl/acl_run.h
+++ b/lib/acl/acl_run.h
@@ -55,12 +55,12 @@ struct acl_flow_data {
  * Structure to maintain running results for
  * a single packet (up to 4 tries).
  */
-struct completion {
+struct __rte_aligned(XMM_SIZE) completion {
 	uint32_t *results;                          /* running results. */
 	int32_t   priority[RTE_ACL_MAX_CATEGORIES]; /* running priorities. */
 	uint32_t  count;                            /* num of remaining tries */
 	/* true for allocated struct */
-} __rte_aligned(XMM_SIZE);
+};
 
 /*
  * One parms structure for each slot in the search engine.
diff --git a/lib/acl/acl_run_altivec.h b/lib/acl/acl_run_altivec.h
index 3c30466..2d398ff 100644
--- a/lib/acl/acl_run_altivec.h
+++ b/lib/acl/acl_run_altivec.h
@@ -3,15 +3,17 @@
  * Copyright (C) IBM Corporation 2016.
  */
 
+#include <stdalign.h>
+
 #include "acl_run.h"
 #include "acl_vect.h"
 
-struct _altivec_acl_const {
+alignas(RTE_CACHE_LINE_SIZE) struct _altivec_acl_const {
 	rte_xmm_t xmm_shuffle_input;
 	rte_xmm_t xmm_index_mask;
 	rte_xmm_t xmm_ones_16;
 	rte_xmm_t range_base;
-} altivec_acl_const __rte_cache_aligned = {
+} altivec_acl_const = {
 	{
 		.u32 = {0x00000000, 0x04040404, 0x08080808, 0x0c0c0c0c}
 	},
diff --git a/lib/acl/acl_run_neon.h b/lib/acl/acl_run_neon.h
index 69d1b6d..63074f8 100644
--- a/lib/acl/acl_run_neon.h
+++ b/lib/acl/acl_run_neon.h
@@ -2,14 +2,16 @@
  * Copyright(c) 2015 Cavium, Inc
  */
 
+#include <stdalign.h>
+
 #include "acl_run.h"
 #include "acl_vect.h"
 
-struct _neon_acl_const {
+alignas(RTE_CACHE_LINE_SIZE) struct _neon_acl_const {
 	rte_xmm_t xmm_shuffle_input;
 	rte_xmm_t xmm_index_mask;
 	rte_xmm_t range_base;
-} neon_acl_const __rte_cache_aligned = {
+} neon_acl_const = {
 	{
 		.u32 = {0x00000000, 0x04040404, 0x08080808, 0x0c0c0c0c}
 	},
-- 
1.8.3.1