ck_pr: Add basic ck_pr_rfo interface.

This leverages prefetchw that is now finally available on both AMD and Intel
processors. Additional ports coming.

configure

@@ -103,6 +103,7 @@ generate()
 	    -e "s#@GZIP_SUFFIX@#$GZIP_SUFFIX#g"			\
 	    -e "s#@POINTER_PACK_ENABLE@#$POINTER_PACK_ENABLE#g"	\
 	    -e "s#@RTM_ENABLE@#$RTM_ENABLE#g"			\
+	    -e "s#@RFO_ENABLE@#$RFO_ENABLE#g"			\
 	    -e "s#@VMA_BITS@#$VMA_BITS_R#g"			\
 	    -e "s#@VMA_BITS_VALUE@#$VMA_BITS_VALUE_R#g"		\
 	    -e "s#@MM@#$MM#g"					\
@@ -137,6 +138,7 @@ generate_stdout()
 	echo "      POINTER_PACK = $POINTER_PACK_ENABLE"
 	echo "          VMA_BITS = $VMA_BITS"
 	echo "      MEMORY_MODEL = $MM"
+	echo "               RFO = $RFO_ENABLE"
 	echo "               RTM = $RTM_ENABLE"
 	echo
 	echo "Headers will be installed in $HEADERS"
@@ -170,13 +172,16 @@ for option; do
 		echo "  --mandir=N               Manual pages directory (default is ${PREFIX}/man)"
 		echo "  --prefix=N               Installs library files in N (default is $PREFIX)"
 		echo
-		echo "The following options will modify code generation."
-		echo "  --cores=N                Specify number of cores available on target machine"
+		echo "The following options will affect generated code."
 		echo "  --enable-pointer-packing Assumes address encoding is subset of pointer range"
-		echo "  --enable-rtm             Enable restricted transactional memory (x86_64 only)"
+		echo "  --enable-rtm             Enable restricted transactional memory (power, x86_64)"
+		echo "  --enable-rfo             Enable read-for-ownership interface (power, x86_64)"
 		echo "  --memory-model=N         Specify memory model (currently tso, pso or rmo)"
 		echo "  --vma-bits=N             Specify valid number of VMA bits"
 		echo
+		echo "The following options affect regression testing."
+		echo "  --cores=N                Specify number of cores available on target machine"
+		echo
 		echo "The following environment variables may be used:"
 		echo "   CC       C compiler command"
 		echo "   CFLAGS   C compiler flags"
@@ -212,6 +217,9 @@ for option; do
 	--enable-rtm)
 		RTM_ENABLE_SET="CK_MD_RTM_ENABLE"
 		;;
+	--enable-rfo)
+		RFO_ENABLE_SET="CK_MD_RFO_ENABLE"
+		;;
 	--cores=*)
 		CORES=$value
 		;;
@@ -272,6 +280,7 @@ MANDIR=${MANDIR:-"${PREFIX}/share/man"}
 GZIP=${GZIP:-"gzip -c"}
 POINTER_PACK_ENABLE=${POINTER_PACK_ENABLE:-"CK_MD_POINTER_PACK_DISABLE"}
 RTM_ENABLE=${RTM_ENABLE_SET:-"CK_MD_RTM_DISABLE"}
+RFO_ENABLE=${RFO_ENABLE_SET:-"CK_MD_RFO_DISABLE"}
 VMA_BITS=${VMA_BITS:-"unknown"}
 
 if test "$PROFILE"; then

include/ck_md.h.in

@@ -39,6 +39,10 @@
 #define @RTM_ENABLE@
 #endif /* @RTM_ENABLE@ */
 
+#ifndef @RFO_ENABLE@
+#define @RFO_ENABLE@
+#endif /* @RFO_ENABLE@ */
+
 #ifndef @POINTER_PACK_ENABLE@
 #define @POINTER_PACK_ENABLE@
 #endif /* @POINTER_PACK_ENABLE@ */

include/ck_pr.h

@@ -138,6 +138,17 @@ CK_PR_FENCE_NOOP(release)
 #undef CK_PR_FENCE_EMIT
 #undef CK_PR_FENCE_NOOP
 
+#ifndef CK_F_PR_RFO
+#define CK_F_PR_RFO
+CK_CC_INLINE static void
+ck_pr_rfo(const void *m)
+{
+
+	(void)m;
+	return;
+}
+#endif /* CK_F_PR_RFO */
+
 #define CK_PR_BIN(K, S, M, T, P, C)					\
 	CK_CC_INLINE static void					\
 	ck_pr_##K##_##S(M *target, T value)				\

include/gcc/x86_64/ck_pr.h

@@ -91,6 +91,26 @@ CK_PR_FENCE(acquire, "mfence")
 
 #undef CK_PR_FENCE
 
+/*
+ * Read for ownership. Older compilers will generate the 32-bit
+ * 3DNow! variant which is binary compatible with x86-64 variant
+ * of prefetchw.
+ */
+#ifdef CK_MD_RFO_ENABLE
+#define CK_F_PR_RFO
+CK_CC_INLINE static void
+ck_pr_rfo(const void *m)
+{
+
+	__asm__ __volatile__("prefetchw (%0)"
+	    :
+	    : "r" (m)
+	    : "memory");
+
+	return;
+}
+#endif /* CD_MD_PREFETCHW_ENABLE */
+
 /*
  * Atomic fetch-and-store operations.
  */