Allow X and Y registers to be overloaded with any literal

Consider the try_case_end instruction:

  try_case_end s

The 's' operand type means that the operand can either be a
literal of one of the types atom, integer, or empty list, or
a register. That worked well before R12. In R12 additional
types of literals where introduced. Because of way the
overloading was done, an 's' operand cannot handle the
new types of literals. Therefore, code such as the following
is necessary in ops.tab to avoid giving an 's' operand a
literal:

  try_case_end Literal=q => move Literal x | try_case_end x

While this work, it is error-prone in that it is easy to
forget to add that kind of rule. It would also be complicated
in case we wanted to introduce a new kind of addition operator
such as:

  i_plus jssd

Since there are two 's' operands, two scratch registers and
two 'move' instructions would be needed.

Therefore, we'll need to find a smarter way to find tag
register operands. We will overload the pid and port tags
for X and Y register, respectively. That works because pids
and port are immediate values (fit in one word), and there
are no literals for pids and ports.

1 files changed, 2 insertions, 27 deletions

diff --git a/erts/emulator/beam/ops.tab b/erts/emulator/beam/ops.tab
index 1d32e72247..4fa6a087e2 100644
--- a/erts/emulator/beam/ops.tab
+++ b/erts/emulator/beam/ops.tab
@@ -237,12 +237,10 @@ try Y F => catch Y F
 try_case Y => try_end Y
 try_end y
 
-try_case_end Literal=q => move Literal x | try_case_end x
 try_case_end s
 
 # Destructive set tuple element
 
-set_tuple_element Lit=q Tuple Pos => move Lit x | set_tuple_element x Tuple Pos
 set_tuple_element s d P
 
 # Get tuple element
@@ -273,8 +271,8 @@ is_number Fail Literal=q => move Literal x | is_number Fail x
 
 jump f
 
-case_end Literal=cq => move Literal x | case_end x
-badmatch Literal=cq => move Literal x | badmatch x
+case_end Literal=c => move Literal x | case_end x
+badmatch Literal=c => move Literal x | badmatch x
 
 case_end r
 case_end x
@@ -849,7 +847,6 @@ is_boolean f y
 
 is_function2 Fail=f acq Arity => jump Fail
 is_function2 Fail=f Fun a => jump Fail
-is_function2 Fail Fun Literal=q => move Literal x | is_function2 Fail Fun x
 
 is_function2 f s s
 %macro: is_function2 IsFunction2 -fail_action
@@ -1122,11 +1119,8 @@ bif1 Fail Bif=u$bif:erlang:get/1 Src=s Dst=d => i_get Src Dst
 
 bif2 Jump=j u$bif:erlang:element/2 S1=s S2=rxy Dst=d => gen_element(Jump, S1, S2, Dst)
 
-bif1 Fail Bif Literal=q Dst => move Literal x | bif1 Fail Bif x Dst
 bif1 p Bif S1 Dst => bif1_body Bif S1 Dst
 
-bif1_body Bif Literal=q Dst => move Literal x | bif1_body Bif x Dst
-
 bif2 p Bif S1 S2 Dst => i_fetch S1 S2 | i_bif2_body Bif Dst
 bif2 Fail Bif S1 S2 Dst => i_fetch S1 S2 | i_bif2 Fail Bif Dst
 
@@ -1439,8 +1433,6 @@ i_bs_private_append j I d
 # Storing integers into binaries.
 #
 
-bs_put_integer Fail=j Sz=s Unit=u Flags=u Literal=q => \
-	move Literal x | bs_put_integer Fail Sz Unit Flags x
 bs_put_integer Fail=j Sz=sq Unit=u Flags=u Src=s => \
 			gen_put_integer(Fail, Sz, Unit, Flags, Src)
 
@@ -1454,32 +1446,22 @@ i_new_bs_put_integer_imm j I I s
 # Utf8/utf16/utf32 support. (R12B-5)
 #
 
-bs_utf8_size Fail Literal=q Dst=d => \
-	move Literal x | bs_utf8_size Fail x Dst
 bs_utf8_size j Src=s Dst=d => i_bs_utf8_size Src Dst
 
 i_bs_utf8_size s d
 
-bs_utf16_size Fail Literal=q Dst=d => \
-	move Literal x | bs_utf16_size Fail x Dst
 bs_utf16_size j Src=s Dst=d => i_bs_utf16_size Src Dst
 
 i_bs_utf16_size s d
 
-bs_put_utf8 Fail=j Flags=u Literal=q => \
-	move Literal x | bs_put_utf8 Fail Flags x
 bs_put_utf8 Fail u Src=s => i_bs_put_utf8 Fail Src
 
 i_bs_put_utf8 j s
 
-bs_put_utf16 Fail=j Flags=u Literal=q => \
-	move Literal x | bs_put_utf16 Fail Flags x
 bs_put_utf16 Fail Flags=u Src=s => i_bs_put_utf16 Fail Flags Src
 
 i_bs_put_utf16 j I s
 
-bs_put_utf32 Fail=j Flags=u Literal=q => \
-	move Literal x | bs_put_utf32 Fail Flags x
 bs_put_utf32 Fail=j Flags=u Src=s => \
    i_bs_validate_unicode Fail Src | bs_put_integer Fail i=32 u=1 Flags Src
 
@@ -1490,9 +1472,6 @@ i_bs_validate_unicode j s
 #
 bs_put_float Fail Sz=q Unit Flags Val => badarg Fail
 
-bs_put_float Fail=j Sz Unit=u Flags=u Literal=q => \
-	move Literal x | bs_put_float Fail Sz Unit Flags x
-
 bs_put_float Fail=j Sz=s Unit=u Flags=u Src=s => \
 			gen_put_float(Fail, Sz, Unit, Flags, Src)
 
@@ -1506,8 +1485,6 @@ i_new_bs_put_float_imm j I I s
 # Storing binaries into binaries.
 #
 
-bs_put_binary Fail Sz Unit Flags Literal=q => \
- 	move Literal x | bs_put_binary Fail Sz Unit Flags x
 bs_put_binary Fail=j Sz=s Unit=u Flags=u Src=s => \
 			gen_put_binary(Fail, Sz, Unit, Flags, Src)
 
@@ -1731,8 +1708,6 @@ gc_bif2 Fail I Bif S1 S2 Dst => \
 gc_bif3 Fail I Bif S1 S2 S3 Dst => \
 	gen_guard_bif3(Fail, I, Bif, S1, S2, S3, Dst)
 
-i_gc_bif1 Fail Bif V=q Live D => move V x | i_gc_bif1 Fail Bif x Live D
-
 i_gc_bif1 j I s I d
 
 ii_gc_bif2/6