py/emitinlinerv32: Refactor load/store opcodes validation.

This commit minimises the amount of code required to perform validation
of load/store opcodes, streamlining their validation and serialisation.

Load/store opcodes used to be handled as a special case due to how its
peculiar syntax yields parse node arguments that cannot be handled by
the regular validation and serialisation functions.

The changes in this commit attempt to reduce the amount of special code
needed for those opcodes to its bare minimum, by removing the special
opcode handling step, merging the validation and serialisation pass for
the combined offset + base register operand, and integrate said changes
in the existing argument handling structure.

That allowed to rework the special operand parsing function to make it
smaller, and remove the code that performed the special case validation
and emitted the opcode.

Signed-off-by: Alessandro Gatti <a.gatti@frob.it>

1 files changed, 52 insertions, 88 deletions

diff --git a/py/emitinlinerv32.c b/py/emitinlinerv32.c
index 948b69317..a5f4c49c2 100644
--- a/py/emitinlinerv32.c
+++ b/py/emitinlinerv32.c
@@ -223,7 +223,7 @@ typedef struct _opcode_t {
     uint16_t argument1_mask : 4;
     uint16_t argument2_mask : 4;
     uint16_t argument3_mask : 4;
-    uint16_t arguments_count : 2;
+    uint16_t parse_nodes : 2;
     // 2 bits available here
     uint32_t calling_convention : 4;
     uint32_t argument1_kind : 4;
@@ -327,7 +327,7 @@ static const opcode_t OPCODES[] = {
     { MP_QSTR_c_jr,       MASK_FFFFFFFE, MASK_NOT_USED, MASK_NOT_USED, 1, CALL_R,   R,  0, N,   0,  N,  0, RV32_EXT_NONE, asm_rv32_opcode_cjr       },
     { MP_QSTR_c_li,       MASK_FFFFFFFE, MASK_0000003F, MASK_NOT_USED, 2, CALL_RI,  R,  0, I,   0,  N,  0, RV32_EXT_NONE, asm_rv32_opcode_cli       },
     { MP_QSTR_c_lui,      MASK_FFFFFFFA, MASK_0001F800, MASK_NOT_USED, 2, CALL_RI,  R,  0, IUZ, 12, N,  0, RV32_EXT_NONE, asm_rv32_opcode_clui      },
-    { MP_QSTR_c_lw,       MASK_0000FF00, MASK_0000007C, MASK_0000FF00, 3, CALL_RIR, RC, 0, I,   0,  RC, 0, RV32_EXT_NONE, asm_rv32_opcode_clw       },
+    { MP_QSTR_c_lw,       MASK_0000FF00, MASK_0000007C, MASK_0000FF00, 2, CALL_RIR, RC, 0, I,   0,  RC, 0, RV32_EXT_NONE, asm_rv32_opcode_clw       },
     { MP_QSTR_c_lwsp,     MASK_FFFFFFFE, MASK_000000FC, MASK_NOT_USED, 2, CALL_RI,  R,  0, I,   0,  N,  0, RV32_EXT_NONE, asm_rv32_opcode_clwsp     },
     { MP_QSTR_c_mv,       MASK_FFFFFFFE, MASK_FFFFFFFE, MASK_NOT_USED, 2, CALL_RR,  R,  0, R,   0,  N,  0, RV32_EXT_NONE, asm_rv32_opcode_cmv       },
     { MP_QSTR_c_nop,      MASK_NOT_USED, MASK_NOT_USED, MASK_NOT_USED, 0, CALL_N,   N,  0, N,   0,  N,  0, RV32_EXT_NONE, asm_rv32_opcode_cnop      },
@@ -336,7 +336,7 @@ static const opcode_t OPCODES[] = {
     { MP_QSTR_c_srai,     MASK_0000FF00, MASK_0000001F, MASK_NOT_USED, 2, CALL_RI,  RC, 0, IU,  0,  N,  0, RV32_EXT_NONE, asm_rv32_opcode_csrai     },
     { MP_QSTR_c_srli,     MASK_0000FF00, MASK_0000001F, MASK_NOT_USED, 2, CALL_RI,  RC, 0, IU,  0,  N,  0, RV32_EXT_NONE, asm_rv32_opcode_csrli     },
     { MP_QSTR_c_sub,      MASK_0000FF00, MASK_0000FF00, MASK_NOT_USED, 2, CALL_RR,  RC, 0, RC,  0,  N,  0, RV32_EXT_NONE, asm_rv32_opcode_csub      },
-    { MP_QSTR_c_sw,       MASK_0000FF00, MASK_0000007C, MASK_0000FF00, 3, CALL_RIR, RC, 0, I,   0,  RC, 0, RV32_EXT_NONE, asm_rv32_opcode_csw       },
+    { MP_QSTR_c_sw,       MASK_0000FF00, MASK_0000007C, MASK_0000FF00, 2, CALL_RIR, RC, 0, I,   0,  RC, 0, RV32_EXT_NONE, asm_rv32_opcode_csw       },
     { MP_QSTR_c_swsp,     MASK_FFFFFFFF, MASK_000000FC, MASK_NOT_USED, 2, CALL_RI,  R,  0, I,   0,  N,  0, RV32_EXT_NONE, asm_rv32_opcode_cswsp     },
     { MP_QSTR_c_xor,      MASK_0000FF00, MASK_0000FF00, MASK_NOT_USED, 2, CALL_RR,  RC, 0, RC,  0,  N,  0, RV32_EXT_NONE, asm_rv32_opcode_cxor      },
     { MP_QSTR_div,        MASK_FFFFFFFF, MASK_FFFFFFFF, MASK_FFFFFFFF, 3, CALL_RRR, R,  0, R,   0,  R,  0, RV32_EXT_NONE, asm_rv32_opcode_div       },
@@ -346,13 +346,13 @@ static const opcode_t OPCODES[] = {
     { MP_QSTR_jal,        MASK_FFFFFFFF, MASK_001FFFFE, MASK_NOT_USED, 2, CALL_RL,  R,  0, L,   0,  N,  0, RV32_EXT_NONE, asm_rv32_opcode_jal       },
     { MP_QSTR_jalr,       MASK_FFFFFFFF, MASK_FFFFFFFF, MASK_00000FFF, 3, CALL_RRI, R,  0, R,   0,  I,  0, RV32_EXT_NONE, asm_rv32_opcode_jalr      },
     { MP_QSTR_la,         MASK_FFFFFFFF, MASK_FFFFFFFF, MASK_NOT_USED, 2, CALL_RL,  R,  0, L,   0,  N,  0, RV32_EXT_NONE, opcode_la                 },
-    { MP_QSTR_lb,         MASK_FFFFFFFF, MASK_00000FFF, MASK_FFFFFFFF, 3, CALL_RIR, R,  0, I,   0,  R,  0, RV32_EXT_NONE, asm_rv32_opcode_lb        },
-    { MP_QSTR_lbu,        MASK_FFFFFFFF, MASK_00000FFF, MASK_FFFFFFFF, 3, CALL_RIR, R,  0, I,   0,  R,  0, RV32_EXT_NONE, asm_rv32_opcode_lbu       },
-    { MP_QSTR_lh,         MASK_FFFFFFFF, MASK_00000FFF, MASK_FFFFFFFF, 3, CALL_RIR, R,  0, I,   0,  R,  0, RV32_EXT_NONE, asm_rv32_opcode_lh        },
-    { MP_QSTR_lhu,        MASK_FFFFFFFF, MASK_00000FFF, MASK_FFFFFFFF, 3, CALL_RIR, R,  0, I,   0,  R,  0, RV32_EXT_NONE, asm_rv32_opcode_lhu       },
+    { MP_QSTR_lb,         MASK_FFFFFFFF, MASK_00000FFF, MASK_FFFFFFFF, 2, CALL_RIR, R,  0, I,   0,  R,  0, RV32_EXT_NONE, asm_rv32_opcode_lb        },
+    { MP_QSTR_lbu,        MASK_FFFFFFFF, MASK_00000FFF, MASK_FFFFFFFF, 2, CALL_RIR, R,  0, I,   0,  R,  0, RV32_EXT_NONE, asm_rv32_opcode_lbu       },
+    { MP_QSTR_lh,         MASK_FFFFFFFF, MASK_00000FFF, MASK_FFFFFFFF, 2, CALL_RIR, R,  0, I,   0,  R,  0, RV32_EXT_NONE, asm_rv32_opcode_lh        },
+    { MP_QSTR_lhu,        MASK_FFFFFFFF, MASK_00000FFF, MASK_FFFFFFFF, 2, CALL_RIR, R,  0, I,   0,  R,  0, RV32_EXT_NONE, asm_rv32_opcode_lhu       },
     { MP_QSTR_li,         MASK_FFFFFFFF, MASK_FFFFFFFF, MASK_NOT_USED, 2, CALL_RI,  R,  0, I,   0,  N,  0, RV32_EXT_NONE, opcode_li                 },
     { MP_QSTR_lui,        MASK_FFFFFFFF, MASK_FFFFF000, MASK_NOT_USED, 2, CALL_RI,  R,  0, I,   12, N,  0, RV32_EXT_NONE, asm_rv32_opcode_lui       },
-    { MP_QSTR_lw,         MASK_FFFFFFFF, MASK_00000FFF, MASK_FFFFFFFF, 3, CALL_RIR, R,  0, I,   0,  R,  0, RV32_EXT_NONE, asm_rv32_opcode_lw        },
+    { MP_QSTR_lw,         MASK_FFFFFFFF, MASK_00000FFF, MASK_FFFFFFFF, 2, CALL_RIR, R,  0, I,   0,  R,  0, RV32_EXT_NONE, asm_rv32_opcode_lw        },
     { MP_QSTR_mv,         MASK_FFFFFFFF, MASK_FFFFFFFF, MASK_NOT_USED, 2, CALL_RR,  R,  0, R,   0,  N,  0, RV32_EXT_NONE, asm_rv32_opcode_cmv       },
     { MP_QSTR_mul,        MASK_FFFFFFFF, MASK_FFFFFFFF, MASK_FFFFFFFF, 3, CALL_RRR, R,  0, R,   0,  R,  0, RV32_EXT_NONE, asm_rv32_opcode_mul       },
     { MP_QSTR_mulh,       MASK_FFFFFFFF, MASK_FFFFFFFF, MASK_FFFFFFFF, 3, CALL_RRR, R,  0, R,   0,  R,  0, RV32_EXT_NONE, asm_rv32_opcode_mulh      },
@@ -362,8 +362,8 @@ static const opcode_t OPCODES[] = {
     { MP_QSTR_ori,        MASK_FFFFFFFF, MASK_FFFFFFFF, MASK_00000FFF, 3, CALL_RRI, R,  0, R,   0,  I,  0, RV32_EXT_NONE, asm_rv32_opcode_ori       },
     { MP_QSTR_rem,        MASK_FFFFFFFF, MASK_FFFFFFFF, MASK_FFFFFFFF, 3, CALL_RRR, R,  0, R,   0,  R,  0, RV32_EXT_NONE, asm_rv32_opcode_rem       },
     { MP_QSTR_remu,       MASK_FFFFFFFF, MASK_FFFFFFFF, MASK_FFFFFFFF, 3, CALL_RRR, R,  0, R,   0,  R,  0, RV32_EXT_NONE, asm_rv32_opcode_remu      },
-    { MP_QSTR_sb,         MASK_FFFFFFFF, MASK_00000FFF, MASK_FFFFFFFF, 3, CALL_RIR, R,  0, I,   0,  R,  0, RV32_EXT_NONE, asm_rv32_opcode_sb        },
-    { MP_QSTR_sh,         MASK_FFFFFFFF, MASK_00000FFF, MASK_FFFFFFFF, 3, CALL_RIR, R,  0, I,   0,  R,  0, RV32_EXT_NONE, asm_rv32_opcode_sh        },
+    { MP_QSTR_sb,         MASK_FFFFFFFF, MASK_00000FFF, MASK_FFFFFFFF, 2, CALL_RIR, R,  0, I,   0,  R,  0, RV32_EXT_NONE, asm_rv32_opcode_sb        },
+    { MP_QSTR_sh,         MASK_FFFFFFFF, MASK_00000FFF, MASK_FFFFFFFF, 2, CALL_RIR, R,  0, I,   0,  R,  0, RV32_EXT_NONE, asm_rv32_opcode_sh        },
     { MP_QSTR_sh1add,     MASK_FFFFFFFF, MASK_FFFFFFFF, MASK_FFFFFFFF, 3, CALL_RRR, R,  0, R,   0,  R,  0, RV32_EXT_ZBA,  asm_rv32_opcode_sh1add    },
     { MP_QSTR_sh2add,     MASK_FFFFFFFF, MASK_FFFFFFFF, MASK_FFFFFFFF, 3, CALL_RRR, R,  0, R,   0,  R,  0, RV32_EXT_ZBA,  asm_rv32_opcode_sh2add    },
     { MP_QSTR_sh3add,     MASK_FFFFFFFF, MASK_FFFFFFFF, MASK_FFFFFFFF, 3, CALL_RRR, R,  0, R,   0,  R,  0, RV32_EXT_ZBA,  asm_rv32_opcode_sh3add    },
@@ -378,7 +378,7 @@ static const opcode_t OPCODES[] = {
     { MP_QSTR_srl,        MASK_FFFFFFFF, MASK_FFFFFFFF, MASK_FFFFFFFF, 3, CALL_RRR, R,  0, R,   0,  R,  0, RV32_EXT_NONE, asm_rv32_opcode_srl       },
     { MP_QSTR_srli,       MASK_FFFFFFFF, MASK_FFFFFFFF, MASK_0000001F, 3, CALL_RRI, R,  0, R,   0,  IU, 0, RV32_EXT_NONE, asm_rv32_opcode_srli      },
     { MP_QSTR_sub,        MASK_FFFFFFFF, MASK_FFFFFFFF, MASK_FFFFFFFF, 3, CALL_RRR, R,  0, R,   0,  R,  0, RV32_EXT_NONE, asm_rv32_opcode_sub       },
-    { MP_QSTR_sw,         MASK_FFFFFFFF, MASK_00000FFF, MASK_FFFFFFFF, 3, CALL_RIR, R,  0, I,   0,  R,  0, RV32_EXT_NONE, asm_rv32_opcode_sw        },
+    { MP_QSTR_sw,         MASK_FFFFFFFF, MASK_00000FFF, MASK_FFFFFFFF, 2, CALL_RIR, R,  0, I,   0,  R,  0, RV32_EXT_NONE, asm_rv32_opcode_sw        },
     { MP_QSTR_xor,        MASK_FFFFFFFF, MASK_FFFFFFFF, MASK_FFFFFFFF, 3, CALL_RRR, R,  0, R,   0,  R,  0, RV32_EXT_NONE, asm_rv32_opcode_xor       },
     { MP_QSTR_xori,       MASK_FFFFFFFF, MASK_FFFFFFFF, MASK_00000FFF, 3, CALL_RRI, R,  0, R,   0,  I,  0, RV32_EXT_NONE, asm_rv32_opcode_xori      },
 };
@@ -439,6 +439,7 @@ static bool validate_integer(mp_uint_t value, mp_uint_t mask, mp_uint_t flags) {
 
 static bool serialise_argument(emit_inline_asm_t *emit, const opcode_t *opcode, mp_parse_node_t node, mp_uint_t node_index, mp_uint_t *serialised) {
     assert((node_index < 3) && "Invalid argument node number.");
+    assert(serialised && "Serialised value pointer is NULL.");
 
     uint32_t kind = 0;
     uint32_t shift = 0;
@@ -562,10 +563,7 @@ static bool serialise_argument(emit_inline_asm_t *emit, const opcode_t *opcode,
             break;
     }
 
-    if (serialised != NULL) {
-        *serialised = serialised_value;
-    }
-
+    *serialised = serialised_value;
     return true;
 
 out_of_range:
@@ -581,19 +579,18 @@ zero_immediate:
     return false;
 }
 
-static bool parse_register_offset_node(emit_inline_asm_t *emit, qstr opcode_qstr, const opcode_t *opcode_data, mp_parse_node_t node, mp_uint_t node_index, mp_parse_node_t *register_node, mp_parse_node_t *offset_node, bool *negative) {
-    assert(register_node != NULL && "Register node pointer is NULL.");
-    assert(offset_node != NULL && "Offset node pointer is NULL.");
-    assert(negative != NULL && "Negative pointer is NULL.");
+static bool serialise_register_offset_node(emit_inline_asm_t *emit, const opcode_t *opcode_data, mp_parse_node_t node, mp_uint_t node_index, mp_uint_t *offset, mp_uint_t *base) {
+    assert(offset && "Attempting to store the offset value into NULL.");
+    assert(base && "Attempting to store the base register into NULL.");
 
     if (!MP_PARSE_NODE_IS_STRUCT_KIND(node, PN_atom_expr_normal) && !MP_PARSE_NODE_IS_STRUCT_KIND(node, PN_factor_2)) {
         goto invalid_structure;
     }
     mp_parse_node_struct_t *node_struct = (mp_parse_node_struct_t *)node;
-    *negative = false;
+    bool negative = false;
     if (MP_PARSE_NODE_IS_STRUCT_KIND(node, PN_factor_2)) {
         if (MP_PARSE_NODE_IS_TOKEN_KIND(node_struct->nodes[0], MP_TOKEN_OP_MINUS)) {
-            *negative = true;
+            negative = true;
         } else {
             if (!MP_PARSE_NODE_IS_TOKEN_KIND(node_struct->nodes[0], MP_TOKEN_OP_PLUS)) {
                 goto invalid_structure;
@@ -605,41 +602,40 @@ static bool parse_register_offset_node(emit_inline_asm_t *emit, qstr opcode_qstr
         node_struct = (mp_parse_node_struct_t *)node_struct->nodes[1];
     }
 
-    if (*negative) {
+    if (negative) {
         // If the value is negative, RULE_atom_expr_normal's first token will be the
         // offset stripped of its negative marker; range check will then fail if the
         // default method is used, so a custom check is used instead.
         mp_obj_t object;
         if (!mp_parse_node_get_int_maybe(node_struct->nodes[0], &object)) {
             emit_inline_rv32_error_exc(emit,
-                mp_obj_new_exception_msg_varg(&mp_type_SyntaxError, ET_WRONG_ARGUMENT_KIND, opcode_qstr, 2, MP_QSTR_integer));
+                mp_obj_new_exception_msg_varg(&mp_type_SyntaxError, ET_WRONG_ARGUMENT_KIND, opcode_data->qstring, 2, MP_QSTR_integer));
             return false;
         }
         mp_uint_t value = mp_obj_get_int_truncated(object);
         value = (~value + 1) & (mp_uint_t)-1;
         if (!validate_integer(value << opcode_data->argument2_shift, OPCODE_MASKS[opcode_data->argument2_mask], opcode_data->argument2_kind)) {
             emit_inline_rv32_error_exc(emit,
-                mp_obj_new_exception_msg_varg(&mp_type_SyntaxError, ET_OUT_OF_RANGE, opcode_qstr, 2));
+                mp_obj_new_exception_msg_varg(&mp_type_SyntaxError, ET_OUT_OF_RANGE, opcode_data->qstring, 2));
             return false;
         }
+        *offset = value;
     } else {
-        if (!serialise_argument(emit, opcode_data, node_struct->nodes[0], 1, NULL)) {
+        if (!serialise_argument(emit, opcode_data, node_struct->nodes[0], 1, offset)) {
             return false;
         }
     }
 
-    *offset_node = node_struct->nodes[0];
     node_struct = (mp_parse_node_struct_t *)node_struct->nodes[1];
-    if (!serialise_argument(emit, opcode_data, node_struct->nodes[0], 2, NULL)) {
+    if (!serialise_argument(emit, opcode_data, node_struct->nodes[0], 2, base)) {
         return false;
     }
-    *register_node = node_struct->nodes[0];
     return true;
 
 invalid_structure:
     emit_inline_rv32_error_exc(emit,
         mp_obj_new_exception_msg_varg(&mp_type_SyntaxError,
-            ET_WRONG_ARGUMENT_KIND, opcode_qstr, node_index + 1, MP_QSTR_offset));
+            ET_WRONG_ARGUMENT_KIND, opcode_data->qstring, node_index + 1, MP_QSTR_offset));
     return false;
 }
 
@@ -685,6 +681,11 @@ static void handle_opcode(emit_inline_asm_t *emit, const opcode_t *opcode_data,
             ((call_rii_t)opcode_data->emitter)(&emit->as, arguments[0], arguments[1], arguments[2]);
             break;
 
+        case CALL_RIR:
+            // The last two arguments indices are swapped on purpose.
+            ((call_rri_t)opcode_data->emitter)(&emit->as, arguments[0], arguments[2], arguments[1]);
+            break;
+
         default:
             assert(!"Unhandled call convention.");
             MP_UNREACHABLE;
@@ -692,42 +693,6 @@ static void handle_opcode(emit_inline_asm_t *emit, const opcode_t *opcode_data,
     }
 }
 
-static bool handle_load_store_opcode_with_offset(emit_inline_asm_t *emit, qstr opcode, const opcode_t *opcode_data, mp_parse_node_t *argument_nodes) {
-    mp_parse_node_t nodes[3] = {0};
-    if (!serialise_argument(emit, opcode_data, argument_nodes[0], 0, NULL)) {
-        return false;
-    }
-    nodes[0] = argument_nodes[0];
-    bool negative = false;
-    if (!parse_register_offset_node(emit, opcode, opcode_data, argument_nodes[1], 1, &nodes[1], &nodes[2], &negative)) {
-        return false;
-    }
-
-    mp_uint_t rd = 0;
-    mp_uint_t rs1 = 0;
-    if (!parse_register_node(nodes[0], &rd, opcode_data->argument1_kind & C)) {
-        return false;
-    }
-    if (!parse_register_node(nodes[1], &rs1, opcode_data->argument3_kind & C)) {
-        return false;
-    }
-
-    mp_obj_t object;
-    mp_parse_node_get_int_maybe(nodes[2], &object);
-    mp_uint_t immediate = mp_obj_get_int_truncated(object) << opcode_data->argument2_shift;
-    if (negative) {
-        immediate = (~immediate + 1) & (mp_uint_t)-1;
-    }
-    if (!is_in_signed_mask(OPCODE_MASKS[opcode_data->argument2_mask], immediate)) {
-        emit_inline_rv32_error_exc(emit,
-            mp_obj_new_exception_msg_varg(&mp_type_SyntaxError, ET_OUT_OF_RANGE, opcode, 2));
-        return false;
-    }
-
-    ((call_rri_t)opcode_data->emitter)(&emit->as, rd, rs1, immediate);
-    return true;
-}
-
 static void emit_inline_rv32_opcode(emit_inline_asm_t *emit, qstr opcode, mp_uint_t arguments_count, mp_parse_node_t *argument_nodes) {
     const opcode_t *opcode_data = NULL;
     for (mp_uint_t index = 0; index < MP_ARRAY_SIZE(OPCODES); index++) {
@@ -747,37 +712,36 @@ static void emit_inline_rv32_opcode(emit_inline_asm_t *emit, qstr opcode, mp_uin
     assert((opcode_data->argument2_mask < MP_ARRAY_SIZE(OPCODE_MASKS)) && "Argument #2 opcode mask index out of bounds.");
     assert((opcode_data->argument3_mask < MP_ARRAY_SIZE(OPCODE_MASKS)) && "Argument #3 opcode mask index out of bounds.");
     assert((opcode_data->calling_convention < CALL_COUNT) && "Calling convention index out of bounds.");
-    if (opcode_data->calling_convention != CALL_RIR) {
-        if (opcode_data->arguments_count != arguments_count) {
-            emit_inline_rv32_error_exc(emit,
-                mp_obj_new_exception_msg_varg(&mp_type_SyntaxError,
-                    ET_WRONG_ARGUMENTS_COUNT, opcode, opcode_data->arguments_count));
-            return;
-        }
-        mp_uint_t serialised_arguments[3] = { 0 };
-        if (opcode_data->arguments_count >= 1 && !serialise_argument(emit, opcode_data, argument_nodes[0], 0, &serialised_arguments[0])) {
+    mp_uint_t serialised_arguments[3] = { 0 };
+    if (arguments_count != opcode_data->parse_nodes) {
+        emit_inline_rv32_error_exc(emit,
+            mp_obj_new_exception_msg_varg(&mp_type_SyntaxError,
+                ET_WRONG_ARGUMENTS_COUNT, opcode, opcode_data->parse_nodes));
+        return;
+    }
+
+    if (opcode_data->parse_nodes >= 1 && !serialise_argument(emit, opcode_data, argument_nodes[0], 0, &serialised_arguments[0])) {
+        return;
+    }
+    if (opcode_data->calling_convention == CALL_RIR) {
+        // "register, offset(base)" calls require some preprocessing to
+        // split the offset and base nodes - not to mention that if the offset
+        // is negative, the parser won't see the offset as a single node but as
+        // a sequence of the minus sign token followed by the number itself.
+
+        if (!serialise_register_offset_node(emit, opcode_data, argument_nodes[1], 1, &serialised_arguments[1], &serialised_arguments[2])) {
             return;
         }
-        if (opcode_data->arguments_count >= 2 && !serialise_argument(emit, opcode_data, argument_nodes[1], 1, &serialised_arguments[1])) {
+    } else {
+        if (opcode_data->parse_nodes >= 2 && !serialise_argument(emit, opcode_data, argument_nodes[1], 1, &serialised_arguments[1])) {
             return;
         }
-        if (opcode_data->arguments_count >= 3 && !serialise_argument(emit, opcode_data, argument_nodes[2], 2, &serialised_arguments[2])) {
+        if (opcode_data->parse_nodes >= 3 && !serialise_argument(emit, opcode_data, argument_nodes[2], 2, &serialised_arguments[2])) {
             return;
         }
-        handle_opcode(emit, opcode_data, serialised_arguments);
-        return;
-    }
-
-    assert((opcode_data->argument2_kind & U) == 0 && "Offset must not be unsigned.");
-    assert((opcode_data->argument2_kind & Z) == 0 && "Offset can be zero.");
-
-    if (arguments_count != 2) {
-        emit_inline_rv32_error_exc(emit,
-            mp_obj_new_exception_msg_varg(&mp_type_SyntaxError, ET_WRONG_ARGUMENTS_COUNT, opcode, 2));
-        return;
     }
 
-    handle_load_store_opcode_with_offset(emit, opcode, opcode_data, argument_nodes);
+    handle_opcode(emit, opcode_data, serialised_arguments);
 }
 
 #undef N