xl: Use C11 builtin atomics if available.

config/opal_setup_cc.m4

@@ -47,10 +47,46 @@ AC_DEFUN([OPAL_PROG_CC_C11_HELPER],[
 
     opal_prog_cc_c11_helper_CFLAGS_save=$CFLAGS
     CFLAGS="$CFLAGS $1"
+    OPAL_C_COMPILER_VENDOR([opal_c_vendor])
 
     OPAL_CC_HELPER([if $CC $1 supports C11 _Thread_local], [opal_prog_cc_c11_helper__Thread_local_available],
                    [],[[static _Thread_local int  foo = 1;++foo;]])
 
+
+    OPAL_CC_HELPER([if $CC $1 has stdatomic.h], [opal_prog_cc_c11_helper_atomic_has_stdatomic_h],
+                   [[#include <stdatomic.h>]], [])
+    if test $opal_prog_cc_c11_helper_atomic_has_stdatomic_h -eq 0; then
+        if test "$opal_cv_c_compiler_vendor" = "ibm"; then
+            AC_REQUIRE([AC_PROG_GREP])
+            tmp=`which gcc`
+            if test $? -eq 0; then
+                stdatomic_include_path=""
+                AC_MSG_CHECKING([if gcc has stdatomic.h])
+                AC_LANG_CONFTEST([AC_LANG_SOURCE([
+                                                  #include<stdatomic.h>
+                                                  int main() { }
+                                                 ]
+                                                )])
+                stdatomic_include_path=`gcc -M conftest.c | $GREP stdatomic.h`
+                if test -z "$stdatomic_include_path"; then
+                    AC_MSG_WARN([stdatomic.h cannot be found. Fallback to C99 atomics.])
+                else
+                    stdatomic_include_path="${stdatomic_include_path#"${stdatomic_include_path%%[![:space:]]*}"}"
+                    stdatomic_include_path=${stdatomic_include_path%stdatomic.h}
+                    CFLAGS="$CFLAGS -I$stdatomic_include_path"
+                    opal_prog_cc_c11_helper_CFLAGS_save="$opal_prog_cc_c11_helper_CFLAGS -I$stdatomic_include_path"
+                    opal_prog_cc_c11_helper_atomic_has_stdatomic_h=1
+                    AC_MSG_RESULT([stdatomic.h is available])
+                    AC_MSG_RESULT([Adding $stdatomic_include_path to include path. Using C11 atomics.])
+                fi
+            else
+                AC_MSG_WARN([No gcc found. Not checking for stdatomic.h include. Fallback to C99 atomics.])
+            fi
+        else
+            AC_MSG_WARN([Not checking for gcc stdatomic.h include. Fallback to C99 atomics.])
+        fi
+    fi
+
     OPAL_CC_HELPER([if $CC $1 supports C11 atomic variables], [opal_prog_cc_c11_helper_atomic_var_available],
                    [[#include <stdatomic.h>]], [[static atomic_long foo = 1;++foo;]])
 
@@ -65,9 +101,9 @@ AC_DEFUN([OPAL_PROG_CC_C11_HELPER],[
 
     OPAL_CC_HELPER([if $CC $1 supports C11 atomic_fetch_xor_explicit], [opal_prog_cc_c11_helper_atomic_fetch_xor_explicit_available],
                    [[#include <stdatomic.h>
-#include <stdint.h>]],[[_Atomic uint32_t a; uint32_t b; atomic_fetch_xor_explicit(&a, b, memory_order_relaxed);]])
+                     #include <stdint.h>]],[[_Atomic uint32_t a; uint32_t b; atomic_fetch_xor_explicit(&a, b, memory_order_relaxed);]])
 
-    AS_IF([test $opal_prog_cc_c11_helper__Thread_local_available -eq 1 && test $opal_prog_cc_c11_helper_atomic_var_available -eq 1 && test $opal_prog_cc_c11_helper_atomic_fetch_xor_explicit_available -eq 1],
+    AS_IF([test $opal_prog_cc_c11_helper__Thread_local_available -eq 1 && test $opal_prog_cc_c11_helper_atomic_var_available -eq 1],
           [$2],
           [$3])
 
@@ -166,7 +202,7 @@ AC_DEFUN([OPAL_SETUP_CC],[
     if test $opal_cv_c11_supported = no ; then
         # It is not currently an error if C11 support is not available. Uncomment the
         # following lines and update the warning when we require a C11 compiler.
-        # AC_MSG_WARNING([Open MPI requires a C11 (or newer) compiler])
+        # AC_MSG_WARN([Open MPI requires a C11 (or newer) compiler])
         # AC_MSG_ERROR([Aborting.])
         # From Open MPI 1.7 on we require a C99 compiant compiler
         AC_PROG_CC_C99
@@ -287,16 +323,20 @@ AC_DEFUN([OPAL_SETUP_CC],[
     OPAL_CFLAGS_BEFORE_PICKY="$CFLAGS"
 
     if test $WANT_PICKY_COMPILER -eq 1; then
-        _OPAL_CHECK_SPECIFIC_CFLAGS(-Wundef, Wundef)
+        if test "$opal_cv_c_compiler_vendor" != "portland group"; then
+            _OPAL_CHECK_SPECIFIC_CFLAGS(-Wundef, Wundef)
+            _OPAL_CHECK_SPECIFIC_CFLAGS(-Wmissing-prototypes, Wmissing_prototypes)
+            _OPAL_CHECK_SPECIFIC_CFLAGS(-Wstrict-prototypes, Wstrict_prototypes)
+        fi
         _OPAL_CHECK_SPECIFIC_CFLAGS(-Wno-long-long, Wno_long_long, int main() { long long x; })
         _OPAL_CHECK_SPECIFIC_CFLAGS(-Wsign-compare, Wsign_compare)
-        _OPAL_CHECK_SPECIFIC_CFLAGS(-Wmissing-prototypes, Wmissing_prototypes)
-        _OPAL_CHECK_SPECIFIC_CFLAGS(-Wstrict-prototypes, Wstrict_prototypes)
         _OPAL_CHECK_SPECIFIC_CFLAGS(-Wcomment, Wcomment)
         _OPAL_CHECK_SPECIFIC_CFLAGS(-Werror-implicit-function-declaration, Werror_implicit_function_declaration)
         _OPAL_CHECK_SPECIFIC_CFLAGS(-Wno-long-double, Wno_long_double, int main() { long double x; })
         _OPAL_CHECK_SPECIFIC_CFLAGS(-fno-strict-aliasing, fno_strict_aliasing, int main() { long double x; })
-        _OPAL_CHECK_SPECIFIC_CFLAGS(-pedantic, pedantic)
+        if test "$opal_cv_c_compiler_vendor" != "ibm" && test "$opal_cv_c_compiler_vendor" != "portland group"; then
+            _OPAL_CHECK_SPECIFIC_CFLAGS(-pedantic, pedantic)
+        fi
         _OPAL_CHECK_SPECIFIC_CFLAGS(-Wall, Wall)
     fi
 

ompi/mca/osc/rdma/osc_rdma_active_target.c

@@ -240,6 +240,20 @@ static void ompi_osc_rdma_check_posts (ompi_osc_rdma_module_t *module)
     }
 }
 
+#if defined(__ibmxl__)
+// Work around an xl optimization bug that would cause the compiler to segv.
+//
+// xl doesn't like something about caching and checking the return value of
+// ompi_osc_rdma_lock_compare_exchange() below when the opt-level is high.
+// For now work around this bug by lowering the optimization on this function
+// with xl compilers.
+//
+// Found on:
+// $. xlc --version
+//   IBM XL C/C++ for Linux, V16.1.1 (5725-C73, 5765-J13)
+//   Version: 16.01.0001.0008
+#pragma option_override(ompi_osc_rdma_post_peer, "opt(level,0)")
+#endif
 static int ompi_osc_rdma_post_peer (ompi_osc_rdma_module_t *module, ompi_osc_rdma_peer_t *peer)
 {
     uint64_t target = (uint64_t) (intptr_t) peer->state + offsetof (ompi_osc_rdma_state_t, post_index);

opal/include/opal/opal_portable_platform.h

@@ -180,7 +180,7 @@
 #    else
 #        define PLATFORM_COMPILER_XLC_C  1
 #    endif
-#    define PLATFORM_COMPILER_VERSION __xlC__
+#    define PLATFORM_COMPILER_VERSION __ibmxl_version__
 #    define PLATFORM_COMPILER_VERSION_INT(maj,min,pat) \
          ( ((maj) << 8) | ((min) << 4) | (pat) )
 

opal/include/opal/sys/atomic.h

@@ -97,6 +97,7 @@ BEGIN_C_DECLS
  * to use an int or unsigned char as the lock value - the user is not
  * informed either way.
  */
+#ifndef OPAL_USE_ATOMIC_FLAG_OPAL_LOCK
 struct opal_atomic_lock_t {
     union {
         opal_atomic_int32_t lock;     /**< The lock address (an integer) */
@@ -105,7 +106,7 @@ struct opal_atomic_lock_t {
     } u;
 };
 typedef struct opal_atomic_lock_t opal_atomic_lock_t;
-
+#endif
 /**********************************************************************
  *
  * Set or unset these macros in the architecture-specific atomic.h
@@ -164,7 +165,7 @@ enum {
  *********************************************************************/
 #if defined(DOXYGEN)
 /* don't include system-level gorp when generating doxygen files */
-#elif OPAL_ASSEMBLY_BUILTIN == OPAL_BUILTIN_GCC
+#elif OPAL_ASSEMBLY_BUILTIN == OPAL_BUILTIN_GCC || OPAL_ASSEMBLY_ARCH == OPAL_POWERPC32 || OPAL_ASSEMBLY_ARCH == OPAL_POWERPC64
 #include "opal/sys/gcc_builtin/atomic.h"
 #elif OPAL_ASSEMBLY_ARCH == OPAL_X86_64
 #include "opal/sys/x86_64/atomic.h"
@@ -174,10 +175,6 @@ enum {
 #include "opal/sys/arm64/atomic.h"
 #elif OPAL_ASSEMBLY_ARCH == OPAL_IA32
 #include "opal/sys/ia32/atomic.h"
-#elif OPAL_ASSEMBLY_ARCH == OPAL_POWERPC32
-#include "opal/sys/powerpc/atomic.h"
-#elif OPAL_ASSEMBLY_ARCH == OPAL_POWERPC64
-#include "opal/sys/powerpc/atomic.h"
 #endif
 
 #ifndef DOXYGEN

opal/include/opal/sys/atomic_stdc.h

@@ -97,10 +97,28 @@ static inline void opal_atomic_rmb (void)
 #define opal_atomic_compare_exchange_strong_acq(addr, oldval, newval)  atomic_compare_exchange_strong_explicit (addr, oldval, newval, memory_order_acquire, memory_order_relaxed)
 #define opal_atomic_compare_exchange_strong_rel(addr, oldval, newval)  atomic_compare_exchange_strong_explicit (addr, oldval, newval, memory_order_release, memory_order_relaxed)
 
+#if defined(__PGI) || defined(__ibmxl__)
+#define opal_atomic_swap_32(addr, value) atomic_exchange_explicit (addr, value, memory_order_relaxed)
+#define opal_atomic_swap_64(addr, value) atomic_exchange_explicit (addr, value, memory_order_relaxed)
+#define opal_atomic_swap_ptr(addr, value) atomic_exchange_explicit (addr, value, memory_order_relaxed)
+#else
 #define opal_atomic_swap_32(addr, value) atomic_exchange_explicit ((_Atomic unsigned int *)addr, value, memory_order_relaxed)
 #define opal_atomic_swap_64(addr, value) atomic_exchange_explicit ((_Atomic unsigned long *)addr, value, memory_order_relaxed)
 #define opal_atomic_swap_ptr(addr, value) atomic_exchange_explicit ((_Atomic unsigned long *)addr, value, memory_order_relaxed)
+#endif
 
+#if defined(__PGI) || defined(__ibmxl__)
+#define OPAL_ATOMIC_STDC_DEFINE_FETCH_OP(op, bits, type, operator)      \
+    static inline type opal_atomic_fetch_ ## op ##_## bits (opal_atomic_ ## type *addr, type value) \
+    {                                                                   \
+        return atomic_fetch_ ## op ## _explicit ((type *)addr, value, memory_order_relaxed); \
+    }                                                                   \
+                                                                        \
+    static inline type opal_atomic_## op ## _fetch_ ## bits (opal_atomic_ ## type *addr, type value) \
+    {                                                                   \
+        return atomic_fetch_ ## op ## _explicit ((type *)addr, value, memory_order_relaxed) operator value; \
+    }
+#else
 #define OPAL_ATOMIC_STDC_DEFINE_FETCH_OP(op, bits, type, operator)      \
     static inline type opal_atomic_fetch_ ## op ##_## bits (opal_atomic_ ## type *addr, type value) \
     {                                                                   \
@@ -111,6 +129,7 @@ static inline void opal_atomic_rmb (void)
     {                                                                   \
         return atomic_fetch_ ## op ## _explicit (addr, value, memory_order_relaxed) operator value; \
     }
+#endif
 
 OPAL_ATOMIC_STDC_DEFINE_FETCH_OP(add, 32, int32_t, +)
 OPAL_ATOMIC_STDC_DEFINE_FETCH_OP(add, 64, int64_t, +)
@@ -206,22 +225,39 @@ static inline int64_t opal_atomic_max_fetch_64 (opal_atomic_int64_t *addr, int64
 #define OPAL_ATOMIC_LOCK_UNLOCKED false
 #define OPAL_ATOMIC_LOCK_LOCKED true
 
-#define OPAL_ATOMIC_LOCK_INIT ATOMIC_FLAG_INIT
+#define OPAL_USE_C11_ATOMIC_LOCK 1
 
+#define OPAL_USE_ATOMIC_FLAG_OPAL_LOCK 1
+#if defined(__ibmxl__) || defined(__PGI)
+#define OPAL_ATOMIC_LOCK_INIT 0
+typedef _Atomic bool opal_atomic_lock_t;
+#else
+#define OPAL_ATOMIC_LOCK_INIT ATOMIC_FLAG_INIT
 typedef atomic_flag opal_atomic_lock_t;
+#endif
 
 /*
  * Lock initialization function. It set the lock to UNLOCKED.
  */
 static inline void opal_atomic_lock_init (opal_atomic_lock_t *lock, bool value)
 {
+#if defined(__PGI)
+    atomic_flag_clear ((volatile void *) lock);
+#else
     atomic_flag_clear (lock);
+#endif
 }
 
 
 static inline int opal_atomic_trylock (opal_atomic_lock_t *lock)
 {
+
+#if defined(__PGI)
+    return (int) atomic_flag_test_and_set ((volatile void *) lock);
+#else
     return (int) atomic_flag_test_and_set (lock);
+#endif
+
 }
 
 
@@ -234,7 +270,11 @@ static inline void opal_atomic_lock(opal_atomic_lock_t *lock)
 
 static inline void opal_atomic_unlock (opal_atomic_lock_t *lock)
 {
+#if defined(__PGI)
+    atomic_flag_clear ((volatile void *) lock);
+#else
     atomic_flag_clear (lock);
+#endif
 }
 
 

opal/include/opal/sys/powerpc/Makefile.am

@@ -19,5 +19,4 @@
 # This makefile.am does not stand on its own - it is included from opal/include/Makefile.am
 
 headers += \
-	opal/sys/powerpc/atomic.h \
 	opal/sys/powerpc/timer.h