Add ldxr tests

tests/ldxr_l.c

@@ -0,0 +1,33 @@
+#include "test.h"
+
+static uint64_t data[] = { 0xffffffffffffffff, 0, 0x4242424212345678 };
+
+static void
+run_test(jit_state_t *j, uint8_t *arena_base, size_t arena_size)
+{
+#if __WORDSIZE > 32
+  jit_begin(j, arena_base, arena_size);
+
+  const jit_arg_abi_t abi[] = { JIT_ARG_ABI_POINTER, JIT_ARG_ABI_INTMAX };
+  jit_arg_t args[2];
+  const jit_anyreg_t regs[] = { { .gpr=JIT_R0 }, { .gpr=JIT_R1 } };
+
+  jit_receive(j, 2, abi, args);
+  jit_load_args(j, 2, abi, args, regs);
+
+  jit_ldxr_l(j, JIT_R0, JIT_R0, JIT_R1);
+  jit_retr(j, JIT_R0);
+
+  uintmax_t (*f)(void*, uintmax_t) = jit_end(j, NULL);
+
+  ASSERT(f(data, 0) == -1);
+  ASSERT(f(data, 8) == 0);
+  ASSERT(f(data, 16) == data[2]);
+#endif
+}
+
+int
+main (int argc, char *argv[])
+{
+  return main_helper(argc, argv, run_test);
+}