Add the 'S' type for a register source

The type 'd' could be used both for destination registers and
source register.

Restrict the 'd' type to only be used for destinations, and
introduce the new 'S' type to be used when a source must be
a register.

4 files changed, 11 insertions, 6 deletions

diff --git a/erts/emulator/beam/beam_emu.c b/erts/emulator/beam/beam_emu.c
index badfe62aa9..482f99cb78 100644
--- a/erts/emulator/beam/beam_emu.c
+++ b/erts/emulator/beam/beam_emu.c
@@ -153,7 +153,7 @@ do {                                     \
  * Register target (X or Y register).
  */
 
-#define REG_TARGET_PTR(Target) (((Target) & 1) ? &yb(Target-1) : &xb(Target))
+#define REG_TARGET_PTR(Target) (((Target) & 1) ? &yb((Target)-1) : &xb(Target))
 
 /*
  * Special Beam instructions.
@@ -242,6 +242,7 @@ void** beam_ops;
 #define tb(N) (N)
 #define xb(N) (*(Eterm *) (((unsigned char *)reg) + (N)))
 #define yb(N) (*(Eterm *) (((unsigned char *)E) + (N)))
+#define Sb(N) (*REG_TARGET_PTR(N))
 #define lb(N) (*(double *) (((unsigned char *)&(freg[0].fd)) + (N)))
 #define Qb(N) (N)
 #define Ib(N) (N)
diff --git a/erts/emulator/beam/beam_load.c b/erts/emulator/beam/beam_load.c
index 982f998ae3..9ff32e30f3 100644
--- a/erts/emulator/beam/beam_load.c
+++ b/erts/emulator/beam/beam_load.c
@@ -2374,7 +2374,8 @@ load_code(LoaderState* stp)
 		    break;
 		}
 		break;
-	    case 'd':	/* Destination (x(0), x(N), y(N) */
+	    case 'd':	/* Destination (x(N), y(N) */
+            case 'S':   /* Source (x(N), y(N)) */
 		switch (tag) {
 		case TAG_x:
 		    code[ci++] = tmp_op->a[arg].val * sizeof(Eterm);
diff --git a/erts/emulator/beam/ops.tab b/erts/emulator/beam/ops.tab
index 4f79177c89..b6e995fdbe 100644
--- a/erts/emulator/beam/ops.tab
+++ b/erts/emulator/beam/ops.tab
@@ -192,7 +192,7 @@ try_case_end s
 
 # Destructive set tuple element
 
-set_tuple_element s d P
+set_tuple_element s S P
 
 # Get tuple element
 
@@ -1272,9 +1272,9 @@ fmove Arg=l Dst=d => fstore Arg Dst
 fmove Arg=dq Dst=l => fload Arg Dst
 
 fstore l d
-fload dq l
+fload Sq l
 
-fconv d l
+fconv S l
 
 i_fadd l l l
 i_fsub l l l
diff --git a/erts/emulator/utils/beam_makeops b/erts/emulator/utils/beam_makeops
index fcbd3de4c1..ee8b12681f 100755
--- a/erts/emulator/utils/beam_makeops
+++ b/erts/emulator/utils/beam_makeops
@@ -139,6 +139,7 @@ my %arg_size = ('r' => 0,	# x(0) - x register zero
 		'n' => 0,	# NIL (implicit)
 		'c' => 1,	# tagged constant (integer, atom, nil)
 		's' => 1,	# tagged source; any of the above
+                'S' => 1,       # tagged source register (x or y)
 		'd' => 1,	# tagged destination register (r, x, y)
 		'f' => 1,	# failure label
 		'j' => 1,	# either 'f' or 'p'
@@ -188,6 +189,7 @@ sub define_type_bit {
     define_type_bit('s', $type_bit{'d'} | $type_bit{'i'} |
 		    $type_bit{'a'} | $type_bit{'n'} |
 		    $type_bit{'q'});
+    define_type_bit('S', $type_bit{'d'});
     define_type_bit('j', $type_bit{'f'} | $type_bit{'p'});
 
     # Aliases (for matching purposes).
@@ -1258,7 +1260,7 @@ sub basic_generator {
                 push(@f, "r(0)");
                 last SWITCH;
             };
-	    /[lxy]/ and do {
+	    /[lxyS]/ and do {
                 push(@f, $_ . "b(Arg($arg_offset))");
                 last SWITCH;
             };
@@ -1462,6 +1464,7 @@ sub do_pack {
                        'y' => 10,
                        'Q' => 10,
                        'l' => 10,
+                       'S' => 16,
                        'd' => 16,
                        't' => 16);
     if ($wordsize == 64) {