X-Git-Url: https://git.liburcu.org/?p=urcu.git;a=blobdiff_plain;f=include%2Furcu%2Farch.h;fp=include%2Furcu%2Farch.h;h=2bffdbe97d8e20339d1d06ea6ccb66e79b4d366c;hp=620743c0f68fb33dd004d3266bcf900e2a96b898;hb=101389e4df4a9661d22d9e9e7e15a7284ef06d0d;hpb=69fbb39e88b9ac568f0bdbf384932a0cc5c58a02

diff --git a/include/urcu/arch.h b/include/urcu/arch.h
index 620743c..2bffdbe 100644
--- a/include/urcu/arch.h
+++ b/include/urcu/arch.h
@@ -64,15 +64,25 @@
 #define URCU_ARCH_AMD64 1
 #include <urcu/arch/x86.h>
 
-#elif (defined(__i486__) || defined(__i586__) || defined(__i686__))
+#elif (defined(__i386__) || defined(__i386) || defined(__i486__) || defined(__i586__) || defined(__i686__))
 
 #define URCU_ARCH_X86 1
-#include <urcu/arch/x86.h>
-
-#elif (defined(__i386__) || defined(__i386))
 
-#define URCU_ARCH_X86 1
+/*
+ * URCU_ARCH_X86_NO_CAS enables a compat layer that will detect the presence of
+ * the cmpxchg instructions at runtime and provide a compat mode based on a
+ * pthread mutex when it isn't.
+ *
+ * __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4 was introduced in GCC 4.3 and Clang 3.3,
+ * building with older compilers will result in the compat layer always being
+ * used on x86-32.
+ */
+#ifndef __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4
+#define URCU_ARCH_X86_NO_CAS 1
+/* For backwards compat */
 #define URCU_ARCH_I386 1
+#endif
+
 #include <urcu/arch/x86.h>
 
 #elif (defined(__powerpc64__) || defined(__ppc64__))