uatomic/x86: Remove redundant memory barriers

[urcu.git] / configure.ac

diff --git a/configure.ac b/configure.ac
index 7045cdc066660ed78fe93385fbbef89821fcbcd2..2807932258549ab93b012862a8063785748a16fa 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -239,6 +239,11 @@ AE_FEATURE([cds-lfht-iter-debug], [Enable extra debugging checks for lock-free h
 AE_FEATURE_DEFAULT_DISABLE
 AE_FEATURE([compiler-atomic-builtins], [Enable the use of compiler atomic builtins.])
 
+# emit legacy memory barriers
+# Enable by default
+AE_FEATURE_DEFAULT_ENABLE
+AE_FEATURE([legacy-mb], [Disable legacy memory barriers.])
+
 # When given, add -Werror to WARN_CFLAGS and WARN_CXXFLAGS.
 # Disabled by default
 AE_FEATURE_DEFAULT_DISABLE
@@ -272,6 +277,10 @@ AE_IF_FEATURE_ENABLED([compiler-atomic-builtins], [
   AC_DEFINE([CONFIG_RCU_USE_ATOMIC_BUILTINS], [1], [Use compiler atomic builtins.])
 ])
 
+AE_IF_FEATURE_ENABLED([legacy-mb], [
+  AC_DEFINE([CONFIG_RCU_EMIT_LEGACY_MB], [1], [Emit legacy memory barriers that were documented in the APIs.])
+])
+
 ##                                                                          ##
 ## Set automake variables for optional feature conditionnals in Makefile.am ##
 ##                                                                          ##
@@ -336,7 +345,6 @@ AC_CONFIG_FILES([
        src/liburcu-qsbr.pc
        src/liburcu-mb.pc
        src/liburcu-memb.pc
-       src/liburcu-signal.pc
 ])
 
 AC_CONFIG_FILES([tests/utils/env.sh],[chmod +x tests/utils/env.sh])
@@ -390,6 +398,10 @@ AE_PPRINT_PROP_BOOL([Multi-flavor support], 1)
 AE_IS_FEATURE_ENABLED([compiler-atomic-builtins]) && value=1 || value=0
 AE_PPRINT_PROP_BOOL([Use compiler atomic builtins], $value)
 
+# legacy memory barriers
+AE_IS_FEATURE_ENABLED([legacy-mb]) && value=1 || value=0
+AE_PPRINT_PROP_BOOL([Emit legacy memory barriers], $value)
+
 report_bindir="`eval eval echo $bindir`"
 report_libdir="`eval eval echo $libdir`"