commit 1c9caceab03b9d04a4981fe242e5b03c816b1edb
author Willy Tarreau <w@1wt.eu> Fri Feb 21 15:40:58 2020 +0100
committer Christopher Faulet <cfaulet@haproxy.com> Fri Feb 28 11:22:37 2020 +0100
tree de408124cfada3cab7448e790d44025e0b1c0949
parent feceffcd780e20c6c52cfaedd96a186003385465

MINOR: compiler: move CPU capabilities definition from config.h and complete them

These ones are irrelevant to the config but rather to the platform, and
as such are better placed in compiler.h.

Here we take the opportunity for declaring a few extra capabilities:
 - HA_UNALIGNED         : CPU supports unaligned accesses
 - HA_UNALIGNED_LE      : CPU supports unaligned accesses in little endian
 - HA_UNALIGNED_FAST    : CPU supports fast unaligned accesses
 - HA_UNALIGNED_ATOMIC  : CPU supports unaligned accesses in atomics

This will help remove a number of #ifdefs with arch-specific statements.

(cherry picked from commit 0e2686762fa6b6fe51690cdca4273b799c6f2193)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit f75fd4f6e5f26c9528f9573dd7c59e901243a8f2)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>

include/common/compiler.h

diff --git a/include/common/compiler.h b/include/common/compiler.h
index b6f5af6..179b318 100644
--- a/include/common/compiler.h
+++ b/include/common/compiler.h
@@ -151,5 +151,36 @@
 #endif
 #endif
 
+/* Some architectures have a double-word CAS, sometimes even dual-8 bytes.
+ * Some architectures support unaligned accesses, others are fine with them
+ * but only for non-atomic operations. Also mention those supporting unaligned
+ * accesses and being little endian, and those where unaligned accesses are
+ * known to be fast (almost as fast as aligned ones).
+ */
+#if defined(__x86_64__)
+#define HA_UNALIGNED
+#define HA_UNALIGNED_LE
+#define HA_UNALIGNED_LE64
+#define HA_UNALIGNED_FAST
+#define HA_UNALIGNED_ATOMIC
+#define HA_HAVE_CAS_DW
+#define HA_CAS_IS_8B
+#elif defined(__i386__) || defined(__i486__) || defined(__i586__) || defined(__i686__)
+#define HA_UNALIGNED
+#define HA_UNALIGNED_LE
+#define HA_UNALIGNED_ATOMIC
+#elif defined (__aarch64__) || defined(__ARM_ARCH_8A)
+#define HA_UNALIGNED
+#define HA_UNALIGNED_LE
+#define HA_UNALIGNED_LE64
+#define HA_UNALIGNED_FAST
+#define HA_HAVE_CAS_DW
+#define HA_CAS_IS_8B
+#elif defined(__arm__) && (defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__))
+#define HA_UNALIGNED
+#define HA_UNALIGNED_LE
+#define HA_UNALIGNED_FAST
+#define HA_HAVE_CAS_DW
+#endif
 
 #endif /* _COMMON_COMPILER_H */