--- a/FEATURES.txt	Wed May 22 15:10:16 2019 -0400
+++ b/FEATURES.txt	Wed May 22 19:55:32 2019 -0400
@@ -13,7 +13,8 @@
  - /etc/[uw]tmpx symlink
  - /usr/adm symlink
  - legacy accounting and reporting
- - libm's __libm_errno symbol
+ - libm's symbols:
+   - __libm_errno, __mt_fex_sync, __libm_mt_fex_sync
  * moved all /var/adm files to /var/log
  * moved /var/svc/log to /var/log/svc
 

--- a/lib/libm/common/m9x/__fex_hdlr.c	Wed May 22 15:10:16 2019 -0400
+++ b/lib/libm/common/m9x/__fex_hdlr.c	Wed May 22 19:55:32 2019 -0400
@@ -49,13 +49,6 @@
 extern int sigemptyset(sigset_t *);
 extern int sigismember(const sigset_t *, int);
 
-/* external globals */
-void (*__mt_fex_sync)() = NULL; /* for synchronization with libmtsk */
-#pragma weak __mt_fex_sync
-
-void (*__libm_mt_fex_sync)() = NULL; /* new, improved version of above */
-#pragma weak __libm_mt_fex_sync
-
 /* private variables */
 static fex_handler_t main_handlers;
 static int handlers_initialized = 0;
@@ -115,89 +108,6 @@
 	return te;
 }
 
-/*
-*  The following function synchronizes with libmtsk (SPARC only, for now)
-*/
-static void
-__fex_sync_with_libmtsk(int begin, int master)
-{
-	static fenv_t master_env;
-	static int env_initialized = 0;
-	static mutex_t env_lock = DEFAULTMUTEX;
-
-	if (begin) {
-		mutex_lock(&env_lock);
-		if (master) {
-			(void) fegetenv(&master_env);
-			env_initialized = 1;
-		}
-		else if (env_initialized)
-			(void) fesetenv(&master_env);
-		mutex_unlock(&env_lock);
-	}
-	else if (master && fex_get_log())
-		__fex_update_te();
-}
-
-/*
-*  The following function may be used for synchronization with any
-*  internal project that manages multiple threads
-*/
-enum __libm_mt_fex_sync_actions {
-	__libm_mt_fex_start_master = 0,
-	__libm_mt_fex_start_slave,
-	__libm_mt_fex_finish_master,
-	__libm_mt_fex_finish_slave
-};
-
-struct __libm_mt_fex_sync_data {
-	fenv_t	master_env;
-	int		initialized;
-	mutex_t	lock;
-};
-
-static void
-__fex_sync_with_threads(enum __libm_mt_fex_sync_actions action,
-	struct __libm_mt_fex_sync_data *thr_env)
-{
-	switch (action) {
-	case __libm_mt_fex_start_master:
-		mutex_lock(&thr_env->lock);
-		(void) fegetenv(&thr_env->master_env);
-		thr_env->initialized = 1;
-		mutex_unlock(&thr_env->lock);
-		break;
-
-	case __libm_mt_fex_start_slave:
-		mutex_lock(&thr_env->lock);
-		if (thr_env->initialized)
-			(void) fesetenv(&thr_env->master_env);
-		mutex_unlock(&thr_env->lock);
-		break;
-
-	case __libm_mt_fex_finish_master:
-#if defined(__x86)
-		__fex_update_te();
-#else
-		if (fex_get_log())
-			__fex_update_te();
-#endif
-		break;
-
-	case __libm_mt_fex_finish_slave:
-#if defined(__x86)
-		/* clear traps, making all accrued flags visible in status word */
-		{
-			unsigned long   fsr;
-			__fenv_getfsr(&fsr);
-			__fenv_set_te(fsr, 0);
-			__fenv_setfsr(&fsr);
-		}
-#endif
-		break;
-	}
-}
-
 #if defined(__sparc)
 
 /*
@@ -826,10 +736,4 @@
 		__fenv_set_te(fsr, te);
 		__fenv_setfsr(&fsr);
 	}
-
-	/* synchronize with libmtsk */
-	__mt_fex_sync = __fex_sync_with_libmtsk;
-
-	/* synchronize with other projects */
-	__libm_mt_fex_sync = __fex_sync_with_threads;
 }

--- a/lib/libm/common/mapfile-vers	Wed May 22 15:10:16 2019 -0400
+++ b/lib/libm/common/mapfile-vers	Wed May 22 19:55:32 2019 -0400
@@ -687,9 +687,6 @@
 };
 
 SYMBOL_VERSION SUNWprivate_1.3 {
-	global:
-		__libm_mt_fex_sync;		# -lmtsk
-		__mt_fex_sync;			# -lmtsk
 } SUNWprivate_1.2;
 
 SYMBOL_VERSION SUNWprivate_1.2 {