Refactor macros for accessing Beam instructions

The BeamOp() macro in erl_vm.h is clumsy to use. All users
cast the return value to BeamInstr.

Define new macros that are easier to use. In the future,
we might want to pack an operand into the same word as
the pointer to the instruction, so we will define two macros.

BeamIsOpCode() is used to rewrite code like this:

  if (Instr == (BeamInstr) BeamOp(op_i_func_info_IaaI) {
    ...
  }

to:

  if (BeamIsOpCode(Instr, op_i_func_info_IaaI)) {
    ...
  }

BeamOpCodeAddr(op_apply_bif) is used when we need the address
for an instruction.

Also elimiminate the global variables em_* in beam_emu.c.
They are not really needed. Use the BeamOpCodeAddr() macro
instead.

1 files changed, 5 insertions, 6 deletions

diff --git a/erts/emulator/beam/erl_nif.c b/erts/emulator/beam/erl_nif.c
index 43441e0228..f7f12efe28 100644
--- a/erts/emulator/beam/erl_nif.c
+++ b/erts/emulator/beam/erl_nif.c
@@ -292,7 +292,7 @@ schedule(ErlNifEnv* env, NativeFunPtr direct_fp, NativeFunPtr indirect_fp,
     ep = erts_nif_export_schedule(c_p, dirty_shadow_proc,
 				  c_p->current,
 				  c_p->cp,
-				  (BeamInstr) em_call_nif,
+				  BeamOpCodeAddr(op_call_nif),
 				  direct_fp, indirect_fp,
 				  mod, func_name,
 				  argc, (const Eterm *) argv);
@@ -3613,7 +3613,7 @@ static ErtsCodeInfo** get_func_pp(BeamCodeHeader* mod_code, Eterm f_atom, unsign
     int j;
     for (j = 0; j < n; ++j) {
 	ErtsCodeInfo* ci = mod_code->functions[j];
-	ASSERT(ci->op == (BeamInstr) BeamOp(op_i_func_info_IaaI));
+	ASSERT(BeamIsOpCode(ci->op, op_i_func_info_IaaI));
 	if (f_atom == ci->mfa.function
 	    && arity == ci->mfa.arity) {
 	    return mod_code->functions+j;
@@ -3982,13 +3982,12 @@ BIF_RETTYPE load_nif_2(BIF_ALIST_2)
             code_ptr = erts_codeinfo_to_code(ci);
 
 	    if (ci->u.gen_bp == NULL) {
-		code_ptr[0] = (BeamInstr) BeamOp(op_call_nif);
+		code_ptr[0] = BeamOpCodeAddr(op_call_nif);
 	    }
 	    else { /* Function traced, patch the original instruction word */
 		GenericBp* g = ci->u.gen_bp;
-		ASSERT(code_ptr[0] ==
-		       (BeamInstr) BeamOp(op_i_generic_breakpoint));
-		g->orig_instr = (BeamInstr) BeamOp(op_call_nif);
+		ASSERT(BeamIsOpCode(code_ptr[0], op_i_generic_breakpoint));
+		g->orig_instr = BeamOpCodeAddr(op_call_nif);
 	    }
 	    if (f->flags) {
 		code_ptr[3] = (BeamInstr) f->fptr;