Hexagon (target/hexagon) Make generators object oriented - gen_tcg_funcs

The generators are generally a bunch of Python if-then-else
statements based on the regtype and regid.  Encapsulate regtype/regid
into a class hierarchy.  Clients lookup the register and invoke
methods.

This has several advantages for making the code easier to read,
understand, and maintain
- The class name makes it more clear what the operand does
- All the methods for a given type of operand are together
- Don't need hex_common.bad_register
  If a regtype/regid is missing, the lookup in hex_common.get_register
  will fail
- We can remove the functions in hex_common that use regtype/regid
  (e.g., is_read)

This patch creates the class hierarchy in hex_common and converts
gen_tcg_funcs.py.  The other scripts will be converted in subsequent
patches in this series.

Signed-off-by: Taylor Simpson <ltaylorsimpson@gmail.com>
Reviewed-by: Brian Cain <bcain@quicinc.com>
Message-Id: <20231210220712.491494-3-ltaylorsimpson@gmail.com>
Signed-off-by: Brian Cain <bcain@quicinc.com>

1 files changed, 659 insertions, 0 deletions

diff --git a/target/hexagon/hex_common.py b/target/hexagon/hex_common.py
index 0da65d6dd6..979f198a30 100755
--- a/target/hexagon/hex_common.py
+++ b/target/hexagon/hex_common.py
@@ -20,12 +20,15 @@
 import sys
 import re
 import string
+import textwrap
 
 behdict = {}  # tag ->behavior
 semdict = {}  # tag -> semantics
 attribdict = {}  # tag -> attributes
 macros = {}  # macro -> macro information...
 attribinfo = {}  # Register information and misc
+registers = {}  # register -> register functions
+new_registers = {}
 tags = []  # list of all tags
 overrides = {}  # tags with helper overrides
 idef_parser_enabled = {}  # tags enabled for idef-parser
@@ -276,6 +279,10 @@ def helper_needs_next_PC(tag):
     return "A_CALL" in attribdict[tag]
 
 
+def need_next_PC(tag):
+    return "A_CALL" in attribdict[tag]
+
+
 def need_pkt_has_multi_cof(tag):
     return "A_COF" in attribdict[tag]
 
@@ -350,3 +357,655 @@ def read_idef_parser_enabled_file(name):
     with open(name, "r") as idef_parser_enabled_file:
         lines = idef_parser_enabled_file.read().strip().split("\n")
         idef_parser_enabled = set(lines)
+
+
+def is_predicated(tag):
+    return "A_CONDEXEC" in attribdict[tag]
+
+
+def code_fmt(txt):
+    return textwrap.indent(textwrap.dedent(txt), "    ")
+
+
+def hvx_newv(tag):
+    if "A_CVI_NEW" in attribdict[tag]:
+        return "EXT_NEW"
+    elif "A_CVI_TMP" in attribdict[tag] or "A_CVI_TMP_DST" in attribdict[tag]:
+        return "EXT_TMP"
+    else:
+        return "EXT_DFL"
+
+def vreg_offset_func(tag):
+    if "A_CVI_TMP" in attribdict[tag] or "A_CVI_TMP_DST" in attribdict[tag]:
+        return "ctx_tmp_vreg_off"
+    else:
+        return "ctx_future_vreg_off"
+
+class HelperArg:
+    def __init__(self, proto_arg, call_arg, func_arg):
+        self.proto_arg = proto_arg
+        self.call_arg = call_arg
+        self.func_arg = func_arg
+
+class Register:
+    def __init__(self, regtype, regid):
+        self.regtype = regtype
+        self.regid = regid
+        self.reg_num = f"{regtype}{regid}N"
+    def decl_reg_num(self, f, regno):
+        f.write(code_fmt(f"""\
+            const int {self.reg_num} = insn->regno[{regno}];
+        """))
+    def idef_arg(self, declared):
+        declared.append(self.reg_tcg())
+    def helper_arg(self):
+        return HelperArg(
+            self.helper_proto_type(),
+            self.reg_tcg(),
+            f"{self.helper_arg_type()} {self.helper_arg_name()}"
+        )
+
+#
+# Every register is either Single or Pair or Hvx
+#
+class Scalar:
+    def is_scalar_reg(self):
+        return True
+    def is_hvx_reg(self):
+        return False
+    def helper_arg_name(self):
+        return self.reg_tcg()
+
+class Single(Scalar):
+    def helper_proto_type(self):
+        return "s32"
+    def helper_arg_type(self):
+        return "int32_t"
+
+class Pair(Scalar):
+    def helper_proto_type(self):
+        return "s64"
+    def helper_arg_type(self):
+        return "int64_t"
+
+class Hvx:
+    def is_scalar_reg(self):
+        return False
+    def is_hvx_reg(self):
+        return True
+    def hvx_off(self):
+        return f"{self.reg_tcg()}_off"
+    def helper_proto_type(self):
+        return "ptr"
+    def helper_arg_type(self):
+        return "void *"
+    def helper_arg_name(self):
+        return f"{self.reg_tcg()}_void"
+
+#
+# Every register is either Dest or OldSource or NewSource or ReadWrite
+#
+class Dest:
+    def reg_tcg(self):
+        return f"{self.regtype}{self.regid}V"
+    def is_written(self):
+        return True
+    def is_writeonly(self):
+        return True
+    def is_read(self):
+        return False
+    def is_readwrite(self):
+        return False
+
+class Source:
+    def is_written(self):
+        return False
+    def is_writeonly(self):
+        return False
+    def is_read(self):
+        return True
+    def is_readwrite(self):
+        return False
+
+class OldSource(Source):
+    def reg_tcg(self):
+        return f"{self.regtype}{self.regid}V"
+
+class NewSource(Source):
+    def reg_tcg(self):
+        return f"{self.regtype}{self.regid}N"
+
+class ReadWrite:
+    def reg_tcg(self):
+        return f"{self.regtype}{self.regid}V"
+    def is_written(self):
+        return True
+    def is_writeonly(self):
+        return False
+    def is_read(self):
+        return True
+    def is_readwrite(self):
+        return True
+
+class GprDest(Register, Single, Dest):
+    def decl_tcg(self, f, tag, regno):
+        self.decl_reg_num(f, regno)
+        f.write(code_fmt(f"""\
+            TCGv {self.reg_tcg()} = get_result_gpr(ctx, {self.reg_num});
+        """))
+    def log_write(self, f, tag):
+        f.write(code_fmt(f"""\
+            gen_log_reg_write(ctx, {self.reg_num}, {self.reg_tcg()});
+        """))
+
+class GprSource(Register, Single, OldSource):
+    def decl_tcg(self, f, tag, regno):
+        self.decl_reg_num(f, regno)
+        f.write(code_fmt(f"""\
+            TCGv {self.reg_tcg()} = hex_gpr[{self.reg_num}];
+        """))
+
+class GprNewSource(Register, Single, NewSource):
+    def decl_tcg(self, f, tag, regno):
+        f.write(code_fmt(f"""\
+            TCGv {self.reg_tcg()} = get_result_gpr(ctx, insn->regno[{regno}]);
+        """))
+
+class GprReadWrite(Register, Single, ReadWrite):
+    def decl_tcg(self, f, tag, regno):
+        self.decl_reg_num(f, regno)
+        f.write(code_fmt(f"""\
+            TCGv {self.reg_tcg()} = get_result_gpr(ctx, {self.reg_num});
+        """))
+        ## For read/write registers, we need to get the original value into
+        ## the result TCGv.  For predicated instructions, this is done in
+        ## gen_start_packet.  For un-predicated instructions, we do it here.
+        if not is_predicated(tag):
+            f.write(code_fmt(f"""\
+                tcg_gen_mov_tl({self.reg_tcg()}, hex_gpr[{self.reg_num}]);
+            """))
+    def log_write(self, f, tag):
+        f.write(code_fmt(f"""\
+            gen_log_reg_write(ctx, {self.reg_num}, {self.reg_tcg()});
+        """))
+
+class ControlDest(Register, Single, Dest):
+    def decl_reg_num(self, f, regno):
+        f.write(code_fmt(f"""\
+            const int {self.reg_num} = insn->regno[{regno}]  + HEX_REG_SA0;
+        """))
+    def decl_tcg(self, f, tag, regno):
+        self.decl_reg_num(f, regno)
+        f.write(code_fmt(f"""\
+            TCGv {self.reg_tcg()} = get_result_gpr(ctx, {self.reg_num});
+        """))
+    def log_write(self, f, tag):
+        f.write(code_fmt(f"""\
+            gen_write_ctrl_reg(ctx, {self.reg_num}, {self.reg_tcg()});
+        """))
+
+class ControlSource(Register, Single, OldSource):
+    def decl_reg_num(self, f, regno):
+        f.write(code_fmt(f"""\
+            const int {self.reg_num} = insn->regno[{regno}]  + HEX_REG_SA0;
+        """))
+    def decl_tcg(self, f, tag, regno):
+        self.decl_reg_num(f, regno);
+        f.write(code_fmt(f"""\
+            TCGv {self.reg_tcg()} = tcg_temp_new();
+            gen_read_ctrl_reg(ctx, {self.reg_num}, {self.reg_tcg()});
+        """))
+
+class ModifierSource(Register, Single, OldSource):
+    def decl_reg_num(self, f, regno):
+        f.write(code_fmt(f"""\
+            const int {self.reg_num} = insn->regno[{regno}] + HEX_REG_M0;
+        """))
+    def decl_tcg(self, f, tag, regno):
+        self.decl_reg_num(f, regno)
+        f.write(code_fmt(f"""\
+            TCGv {self.reg_tcg()} = hex_gpr[{self.reg_num}];
+            TCGv CS G_GNUC_UNUSED =
+                hex_gpr[{self.reg_num} - HEX_REG_M0 + HEX_REG_CS0];
+        """))
+    def idef_arg(self, declared):
+        declared.append(self.reg_tcg())
+        declared.append("CS")
+
+class PredDest(Register, Single, Dest):
+    def decl_tcg(self, f, tag, regno):
+        self.decl_reg_num(f, regno)
+        f.write(code_fmt(f"""\
+            TCGv {self.reg_tcg()} = tcg_temp_new();
+        """))
+    def log_write(self, f, tag):
+        f.write(code_fmt(f"""\
+            gen_log_pred_write(ctx, {self.reg_num}, {self.reg_tcg()});
+        """))
+
+class PredSource(Register, Single, OldSource):
+    def decl_tcg(self, f, tag, regno):
+        self.decl_reg_num(f, regno)
+        f.write(code_fmt(f"""\
+            TCGv {self.reg_tcg()} = hex_pred[{self.reg_num}];
+        """))
+
+class PredNewSource(Register, Single, NewSource):
+    def decl_tcg(self, f, tag, regno):
+        f.write(code_fmt(f"""\
+            TCGv {self.reg_tcg()} = get_result_pred(ctx, insn->regno[{regno}]);
+        """))
+
+class PredReadWrite(Register, Single, ReadWrite):
+    def decl_tcg(self, f, tag, regno):
+        self.decl_reg_num(f, regno)
+        f.write(code_fmt(f"""\
+            TCGv {self.reg_tcg()} = tcg_temp_new();
+            tcg_gen_mov_tl({self.reg_tcg()}, hex_pred[{self.reg_num}]);
+        """))
+    def log_write(self, f, tag):
+        f.write(code_fmt(f"""\
+            gen_log_pred_write(ctx, {self.reg_num}, {self.reg_tcg()});
+        """))
+
+class PairDest(Register, Pair, Dest):
+    def decl_tcg(self, f, tag, regno):
+        self.decl_reg_num(f, regno)
+        f.write(code_fmt(f"""\
+            TCGv_i64 {self.reg_tcg()} =
+                get_result_gpr_pair(ctx, {self.reg_num});
+        """))
+    def log_write(self, f, tag):
+        f.write(code_fmt(f"""\
+            gen_log_reg_write_pair(ctx, {self.reg_num}, {self.reg_tcg()});
+        """))
+
+class PairSource(Register, Pair, OldSource):
+    def decl_tcg(self, f, tag, regno):
+        self.decl_reg_num(f, regno)
+        f.write(code_fmt(f"""\
+            TCGv_i64 {self.reg_tcg()} = tcg_temp_new_i64();
+            tcg_gen_concat_i32_i64({self.reg_tcg()},
+                                    hex_gpr[{self.reg_num}],
+                                    hex_gpr[{self.reg_num} + 1]);
+        """))
+
+class PairReadWrite(Register, Pair, ReadWrite):
+    def decl_tcg(self, f, tag, regno):
+        self.decl_reg_num(f, regno)
+        f.write(code_fmt(f"""\
+            TCGv_i64 {self.reg_tcg()} =
+                get_result_gpr_pair(ctx, {self.reg_num});
+            tcg_gen_concat_i32_i64({self.reg_tcg()},
+                                   hex_gpr[{self.reg_num}],
+                                   hex_gpr[{self.reg_num} + 1]);
+        """))
+    def log_write(self, f, tag):
+        f.write(code_fmt(f"""\
+            gen_log_reg_write_pair(ctx, {self.reg_num}, {self.reg_tcg()});
+        """))
+
+class ControlPairDest(Register, Pair, Dest):
+    def decl_reg_num(self, f, regno):
+        f.write(code_fmt(f"""\
+            const int {self.reg_num} = insn->regno[{regno}] + HEX_REG_SA0;
+        """))
+    def decl_tcg(self, f, tag, regno):
+        self.decl_reg_num(f, regno)
+        f.write(code_fmt(f"""\
+            TCGv_i64 {self.reg_tcg()} =
+                get_result_gpr_pair(ctx, {self.reg_num});
+        """))
+    def log_write(self, f, tag):
+        f.write(code_fmt(f"""\
+            gen_write_ctrl_reg_pair(ctx, {self.reg_num}, {self.reg_tcg()});
+        """))
+
+class ControlPairSource(Register, Pair, OldSource):
+    def decl_reg_num(self, f, regno):
+        f.write(code_fmt(f"""\
+            const int {self.reg_num} = insn->regno[{regno}] + HEX_REG_SA0;
+        """))
+    def decl_tcg(self, f, tag, regno):
+        self.decl_reg_num(f, regno)
+        f.write(code_fmt(f"""\
+            TCGv_i64 {self.reg_tcg()} = tcg_temp_new_i64();
+            gen_read_ctrl_reg_pair(ctx, {self.reg_num}, {self.reg_tcg()});
+        """))
+
+class VRegDest(Register, Hvx, Dest):
+    def decl_tcg(self, f, tag, regno):
+        self.decl_reg_num(f, regno)
+        f.write(code_fmt(f"""\
+            const intptr_t {self.hvx_off()} =
+                {vreg_offset_func(tag)}(ctx, {self.reg_num}, 1, true);
+        """))
+        if not skip_qemu_helper(tag):
+            f.write(code_fmt(f"""\
+                TCGv_ptr {self.reg_tcg()} = tcg_temp_new_ptr();
+                tcg_gen_addi_ptr({self.reg_tcg()}, tcg_env, {self.hvx_off()});
+            """))
+    def log_write(self, f, tag):
+        pass
+
+class VRegSource(Register, Hvx, OldSource):
+    def decl_tcg(self, f, tag, regno):
+        self.decl_reg_num(f, regno)
+        f.write(code_fmt(f"""\
+            const intptr_t {self.hvx_off()} = vreg_src_off(ctx, {self.reg_num});
+        """))
+        if not skip_qemu_helper(tag):
+            f.write(code_fmt(f"""\
+                TCGv_ptr {self.reg_tcg()} = tcg_temp_new_ptr();
+                tcg_gen_addi_ptr({self.reg_tcg()}, tcg_env, {self.hvx_off()});
+            """))
+
+class VRegNewSource(Register, Hvx, NewSource):
+    def decl_tcg(self, f, tag, regno):
+        self.decl_reg_num(f, regno)
+        if skip_qemu_helper(tag):
+            f.write(code_fmt(f"""\
+                const intptr_t {self.hvx_off()} =
+                    ctx_future_vreg_off(ctx, {self.reg_num}, 1, true);
+            """))
+
+class VRegReadWrite(Register, Hvx, ReadWrite):
+    def decl_tcg(self, f, tag, regno):
+        self.decl_reg_num(f, regno)
+        f.write(code_fmt(f"""\
+            const intptr_t {self.hvx_off()} =
+                {vreg_offset_func(tag)}(ctx, {self.reg_num}, 1, true);
+            tcg_gen_gvec_mov(MO_64, {self.hvx_off()},
+                             vreg_src_off(ctx, {self.reg_num}),
+                             sizeof(MMVector), sizeof(MMVector));
+        """))
+        if not skip_qemu_helper(tag):
+            f.write(code_fmt(f"""\
+                TCGv_ptr {self.reg_tcg()} = tcg_temp_new_ptr();
+                tcg_gen_addi_ptr({self.reg_tcg()}, tcg_env, {self.hvx_off()});
+            """))
+    def log_write(self, f, tag):
+        pass
+
+class VRegTmp(Register, Hvx, ReadWrite):
+    def decl_tcg(self, f, tag, regno):
+        self.decl_reg_num(f, regno)
+        f.write(code_fmt(f"""\
+            const intptr_t {self.hvx_off()} = offsetof(CPUHexagonState, vtmp);
+        """))
+        if not skip_qemu_helper(tag):
+            f.write(code_fmt(f"""\
+                TCGv_ptr {self.reg_tcg()} = tcg_temp_new_ptr();
+                tcg_gen_addi_ptr({self.reg_tcg()}, tcg_env, {self.hvx_off()});
+                tcg_gen_gvec_mov(MO_64, {self.hvx_off()},
+                                 vreg_src_off(ctx, {self.reg_num}),
+                                 sizeof(MMVector), sizeof(MMVector));
+            """))
+    def log_write(self, f, tag):
+        f.write(code_fmt(f"""\
+            gen_log_vreg_write(ctx, {self.hvx_off()}, {self.reg_num},
+                               {hvx_newv(tag)});
+        """))
+
+class VRegPairDest(Register, Hvx, Dest):
+    def decl_tcg(self, f, tag, regno):
+        self.decl_reg_num(f, regno)
+        f.write(code_fmt(f"""\
+            const intptr_t {self.hvx_off()} =
+                {vreg_offset_func(tag)}(ctx, {self.reg_num}, 2, true);
+        """))
+        if not skip_qemu_helper(tag):
+            f.write(code_fmt(f"""\
+                TCGv_ptr {self.reg_tcg()} = tcg_temp_new_ptr();
+                tcg_gen_addi_ptr({self.reg_tcg()}, tcg_env, {self.hvx_off()});
+            """))
+    def log_write(self, f, tag):
+        pass
+
+class VRegPairSource(Register, Hvx, OldSource):
+    def decl_tcg(self, f, tag, regno):
+        self.decl_reg_num(f, regno)
+        f.write(code_fmt(f"""\
+            const intptr_t {self.hvx_off()} =
+                offsetof(CPUHexagonState, {self.reg_tcg()});
+            tcg_gen_gvec_mov(MO_64, {self.hvx_off()},
+                             vreg_src_off(ctx, {self.reg_num}),
+                             sizeof(MMVector), sizeof(MMVector));
+            tcg_gen_gvec_mov(MO_64, {self.hvx_off()} + sizeof(MMVector),
+                             vreg_src_off(ctx, {self.reg_num} ^ 1),
+                             sizeof(MMVector), sizeof(MMVector));
+        """))
+        if not skip_qemu_helper(tag):
+            f.write(code_fmt(f"""\
+                TCGv_ptr {self.reg_tcg()} = tcg_temp_new_ptr();
+                tcg_gen_addi_ptr({self.reg_tcg()}, tcg_env, {self.hvx_off()});
+            """))
+
+class VRegPairReadWrite(Register, Hvx, ReadWrite):
+    def decl_tcg(self, f, tag, regno):
+        self.decl_reg_num(f, regno)
+        f.write(code_fmt(f"""\
+            const intptr_t {self.hvx_off()} =
+                offsetof(CPUHexagonState, {self.reg_tcg()});
+            tcg_gen_gvec_mov(MO_64, {self.hvx_off()},
+                             vreg_src_off(ctx, {self.reg_num}),
+                             sizeof(MMVector), sizeof(MMVector));
+            tcg_gen_gvec_mov(MO_64, {self.hvx_off()} + sizeof(MMVector),
+                             vreg_src_off(ctx, {self.reg_num} ^ 1),
+                             sizeof(MMVector), sizeof(MMVector));
+        """))
+        if not skip_qemu_helper(tag):
+            f.write(code_fmt(f"""\
+                TCGv_ptr {self.reg_tcg()} = tcg_temp_new_ptr();
+                tcg_gen_addi_ptr({self.reg_tcg()}, tcg_env, {self.hvx_off()});
+            """))
+    def log_write(self, f, tag):
+        f.write(code_fmt(f"""\
+            gen_log_vreg_write_pair(ctx, {self.hvx_off()}, {self.reg_num},
+                                    {hvx_newv(tag)});
+        """))
+
+class QRegDest(Register, Hvx, Dest):
+    def decl_tcg(self, f, tag, regno):
+        self.decl_reg_num(f, regno)
+        f.write(code_fmt(f"""\
+            const intptr_t {self.hvx_off()} =
+                get_result_qreg(ctx, {self.reg_num});
+        """))
+        if not skip_qemu_helper(tag):
+            f.write(code_fmt(f"""\
+                TCGv_ptr {self.reg_tcg()} = tcg_temp_new_ptr();
+                tcg_gen_addi_ptr({self.reg_tcg()}, tcg_env, {self.hvx_off()});
+            """))
+    def log_write(self, f, tag):
+        pass
+
+class QRegSource(Register, Hvx, OldSource):
+    def decl_tcg(self, f, tag, regno):
+        self.decl_reg_num(f, regno)
+        f.write(code_fmt(f"""\
+            const intptr_t {self.hvx_off()} =
+                offsetof(CPUHexagonState, QRegs[{self.reg_num}]);
+        """))
+        if not skip_qemu_helper(tag):
+            f.write(code_fmt(f"""\
+                TCGv_ptr {self.reg_tcg()} = tcg_temp_new_ptr();
+                tcg_gen_addi_ptr({self.reg_tcg()}, tcg_env, {self.hvx_off()});
+            """))
+
+class QRegReadWrite(Register, Hvx, ReadWrite):
+    def decl_tcg(self, f, tag, regno):
+        self.decl_reg_num(f, regno)
+        f.write(code_fmt(f"""\
+            const intptr_t {self.hvx_off()} =
+                get_result_qreg(ctx, {self.reg_num});
+            tcg_gen_gvec_mov(MO_64, {self.hvx_off()},
+                             offsetof(CPUHexagonState, QRegs[{self.reg_num}]),
+                             sizeof(MMQReg), sizeof(MMQReg));
+        """))
+        if not skip_qemu_helper(tag):
+            f.write(code_fmt(f"""\
+                TCGv_ptr {self.reg_tcg()} = tcg_temp_new_ptr();
+                tcg_gen_addi_ptr({self.reg_tcg()}, tcg_env, {self.hvx_off()});
+            """))
+    def log_write(self, f, tag):
+        pass
+
+def init_registers():
+    regs = {
+        GprDest("R", "d"),
+        GprDest("R", "e"),
+        GprSource("R", "s"),
+        GprSource("R", "t"),
+        GprSource("R", "u"),
+        GprSource("R", "v"),
+        GprReadWrite("R", "x"),
+        GprReadWrite("R", "y"),
+        ControlDest("C", "d"),
+        ControlSource("C", "s"),
+        ModifierSource("M", "u"),
+        PredDest("P", "d"),
+        PredDest("P", "e"),
+        PredSource("P", "s"),
+        PredSource("P", "t"),
+        PredSource("P", "u"),
+        PredSource("P", "v"),
+        PredReadWrite("P", "x"),
+        PairDest("R", "dd"),
+        PairDest("R", "ee"),
+        PairSource("R", "ss"),
+        PairSource("R", "tt"),
+        PairReadWrite("R", "xx"),
+        PairReadWrite("R", "yy"),
+        ControlPairDest("C", "dd"),
+        ControlPairSource("C", "ss"),
+        VRegDest("V", "d"),
+        VRegSource("V", "s"),
+        VRegSource("V", "u"),
+        VRegSource("V", "v"),
+        VRegSource("V", "w"),
+        VRegReadWrite("V", "x"),
+        VRegTmp("V", "y"),
+        VRegPairDest("V", "dd"),
+        VRegPairSource("V", "uu"),
+        VRegPairSource("V", "vv"),
+        VRegPairReadWrite("V", "xx"),
+        QRegDest("Q", "d"),
+        QRegDest("Q", "e"),
+        QRegSource("Q", "s"),
+        QRegSource("Q", "t"),
+        QRegSource("Q", "u"),
+        QRegSource("Q", "v"),
+        QRegReadWrite("Q", "x"),
+    }
+    for reg in regs:
+        registers[f"{reg.regtype}{reg.regid}"] = reg
+
+    new_regs = {
+        GprNewSource("N", "s"),
+        GprNewSource("N", "t"),
+        PredNewSource("P", "t"),
+        PredNewSource("P", "u"),
+        PredNewSource("P", "v"),
+        VRegNewSource("O", "s"),
+    }
+    for reg in new_regs:
+        new_registers[f"{reg.regtype}{reg.regid}"] = reg
+
+def get_register(tag, regtype, regid):
+    if f"{regtype}{regid}V" in semdict[tag]:
+        return registers[f"{regtype}{regid}"]
+    else:
+        return new_registers[f"{regtype}{regid}"]
+
+def helper_ret_type(tag, regs):
+    ## If there is a scalar result, it is the return type
+    return_type = HelperArg( "void", "void", "void")
+    numscalarresults = 0
+    for regtype, regid in regs:
+        reg = get_register(tag, regtype, regid)
+        if reg.is_written() and reg.is_scalar_reg():
+            return_type = HelperArg(
+                reg.helper_proto_type(),
+                reg.reg_tcg(),
+                reg.helper_arg_type()
+            )
+    if numscalarresults > 1:
+        raise Exception("numscalarresults > 1")
+    return return_type
+
+def helper_args(tag, regs, imms):
+    args = []
+
+    ## First argument is the CPU state
+    args.append(HelperArg(
+        "env",
+        "tcg_env",
+        "CPUHexagonState *env"
+    ))
+
+    ## For predicated instructions, we pass in the destination register
+    if is_predicated(tag):
+        for regtype, regid in regs:
+            reg = get_register(tag, regtype, regid)
+            if reg.is_writeonly() and not reg.is_hvx_reg():
+                args.append(reg.helper_arg())
+
+    ## Pass the HVX destination registers
+    for regtype, regid in regs:
+        reg = get_register(tag, regtype, regid)
+        if reg.is_written() and reg.is_hvx_reg():
+            args.append(reg.helper_arg())
+
+    ## Pass the source registers
+    for regtype, regid in regs:
+        reg = get_register(tag, regtype, regid)
+        if reg.is_read() and not (reg.is_hvx_reg() and reg.is_readwrite()):
+            args.append(reg.helper_arg())
+
+    ## Pass the immediates
+    for immlett, bits, immshift in imms:
+        args.append(HelperArg(
+            "s32",
+            f"tcg_constant_tl({imm_name(immlett)})",
+            f"int32_t {imm_name(immlett)}"
+        ))
+
+    ## Other stuff the helper might need
+    if need_pkt_has_multi_cof(tag):
+        args.append(HelperArg(
+            "i32",
+            "tcg_constant_tl(ctx->pkt->pkt_has_multi_cof)",
+            "uint32_t pkt_has_multi_cof"
+        ))
+    if need_pkt_need_commit(tag):
+        args.append(HelperArg(
+            "i32",
+            "tcg_constant_tl(ctx->need_commit)",
+            "uint32_t pkt_need_commit"
+        ))
+    if need_PC(tag):
+        args.append(HelperArg(
+            "i32",
+            "tcg_constant_tl(ctx->pkt->pc)",
+            "target_ulong PC"
+        ))
+    if need_next_PC(tag):
+        args.append(HelperArg(
+            "i32",
+            "tcg_constant_tl(ctx->next_PC)",
+            "target_ulong next_PC"
+        ))
+    if need_slot(tag):
+        args.append(HelperArg(
+            "i32",
+            "gen_slotval(ctx)",
+            "uint32_t slotval"
+        ))
+    if need_part1(tag):
+        args.append(HelperArg(
+            "i32",
+            "tcg_constant_tl(insn->part1)"
+            "uint32_t part1"
+        ))
+    return args