diff --git a/runtime/src/env.c b/runtime/src/env.c
index 93c0a6e..60088d7 100644
--- a/runtime/src/env.c
+++ b/runtime/src/env.c
@@ -1,5 +1,6 @@
 /* https://github.com/gwsystems/silverfish/blob/master/runtime/libc/libc_backing.c */
 #include <runtime.h>
+#include <ck_pr.h>
 
 extern i32 inner_syscall_handler(i32 n, i32 a, i32 b, i32 c, i32 d, i32 e, i32 f);
 
@@ -33,7 +34,7 @@ INLINE void
 env_a_and_64(i32 p_off, u64 v)
 {
 	uint64_t *p = worker_thread_get_memory_ptr_void(p_off, sizeof(uint64_t));
-	*p &= v;
+	ck_pr_and_64(p, v);
 }
 
 INLINE void
@@ -41,37 +42,37 @@ env_a_or_64(i32 p_off, i64 v)
 {
 	assert(sizeof(i64) == sizeof(uint64_t));
 	uint64_t *p = worker_thread_get_memory_ptr_void(p_off, sizeof(i64));
-	*p |= v;
+	ck_pr_or_64(p, v);
 }
 
 i32
 env_a_cas(i32 p_off, i32 t, i32 s)
 {
 	assert(sizeof(i32) == sizeof(volatile int));
-	volatile int *p = worker_thread_get_memory_ptr_void(p_off, sizeof(i32));
+	int *p = worker_thread_get_memory_ptr_void(p_off, sizeof(i32));
 
-	return __sync_val_compare_and_swap(p, t, s);
+	return ck_pr_cas_int(p, t, s);
 }
 
 void
 env_a_or(i32 p_off, i32 v)
 {
-        assert(sizeof(i32) == sizeof(volatile int));
-        volatile int *p = worker_thread_get_memory_ptr_void(p_off, sizeof(i32));
-        //__asm__("lock ; or %1, %0" : "=m"(*p) : "r"(v) : "memory");
-	*p |= v;
+	assert(sizeof(i32) == sizeof(volatile int));
+	int *p = worker_thread_get_memory_ptr_void(p_off, sizeof(i32));
+	ck_pr_or_int(p, v);
 }
 
 i32
 env_a_swap(i32 x_off, i32 v)
 {
 	assert(sizeof(i32) == sizeof(volatile int));
-	volatile int *x = worker_thread_get_memory_ptr_void(x_off, sizeof(i32));
+	int *x = worker_thread_get_memory_ptr_void(x_off, sizeof(i32));
 
-	//__asm__("xchg %0, %1" : "=r"(v), "=m"(*x) : "0"(v) : "memory");
-	int t = *x;
-	*x = v;
-	v = t;
+	int p;
+	do {
+		p = ck_pr_load_int(x);
+	} while (!ck_pr_cas_int(x, p, v));
+	v = p;
 
 	return v;
 }
@@ -80,39 +81,32 @@ i32
 env_a_fetch_add(i32 x_off, i32 v)
 {
 	assert(sizeof(i32) == sizeof(volatile int));
-	volatile int *x = worker_thread_get_memory_ptr_void(x_off, sizeof(i32));
-
-	//__asm__("lock ; xadd %0, %1" : "=r"(v), "=m"(*x) : "0"(v) : "memory");
-	return __sync_fetch_and_add(x, v);
+	int *x = worker_thread_get_memory_ptr_void(x_off, sizeof(i32));
+	return ck_pr_faa_int(x, v);
 }
 
 void
 env_a_inc(i32 x_off)
 {
 	assert(sizeof(i32) == sizeof(volatile int));
-	volatile int *x = worker_thread_get_memory_ptr_void(x_off, sizeof(i32));
-	(*x)++;
-
-	//__asm__("lock ; incl %0" : "=m"(*x) : "m"(*x) : "memory");
+	int *x = worker_thread_get_memory_ptr_void(x_off, sizeof(i32));
+	ck_pr_inc_int(x);
 }
 
 void
 env_a_dec(i32 x_off)
 {
 	assert(sizeof(i32) == sizeof(volatile int));
-	volatile int *x = worker_thread_get_memory_ptr_void(x_off, sizeof(i32));
-	(*x)--;
-
-	//__asm__("lock ; decl %0" : "=m"(*x) : "m"(*x) : "memory");
+	int *x = worker_thread_get_memory_ptr_void(x_off, sizeof(i32));
+	ck_pr_dec_int(x);
 }
 
 void
 env_a_store(i32 p_off, i32 x)
 {
 	assert(sizeof(i32) == sizeof(volatile int));
-	volatile int *p = worker_thread_get_memory_ptr_void(p_off, sizeof(i32));
-	*p = x;
-	//__asm__ __volatile__("mov %1, %0 ; lock ; orl $0,(%%esp)" : "=m"(*p) : "r"(x) : "memory");
+	int *p = worker_thread_get_memory_ptr_void(p_off, sizeof(i32));
+	ck_pr_store_int(p, x);
 }
 
 int
@@ -124,8 +118,7 @@ env_a_ctz_32(i32 x)
 void
 env_do_spin(i32 i)
 {
-	printf("nope! not happening: %d\n", i);
-	assert(0);
+	ck_pr_stall();
 }
 
 void
@@ -138,7 +131,7 @@ env_do_crash(i32 i)
 void
 env_do_barrier(i32 x)
 {
-	__sync_synchronize();
+	ck_pr_barrier();
 }
 
 // Floating point routines