Hexagon (target/hexagon) Clean up handling of modifier registers

Currently, the register number (MuN) for modifier registers is the
modifier register number rather than the index into hex_gpr.  This
patch changes MuN to the hex_gpr index, which is consistent with
the handling of control registers.

Note that HELPER(fcircadd) needs the CS register corresponding to the
modifier register specified in the instruction.  We create a TCGv
variable "CS" to hold the value to pass to the helper.

Reviewed-by: Brian Cain <bcain@quicinc.com>
Signed-off-by: Taylor Simpson <ltaylorsimpson@gmail.com>
Message-Id: <20231210220712.491494-2-ltaylorsimpson@gmail.com>
Signed-off-by: Brian Cain <bcain@quicinc.com>

1 files changed, 9 insertions, 4 deletions

diff --git a/target/hexagon/gen_tcg_funcs.py b/target/hexagon/gen_tcg_funcs.py
index f5246cee6d..02d93bc5ce 100755
--- a/target/hexagon/gen_tcg_funcs.py
+++ b/target/hexagon/gen_tcg_funcs.py
@@ -99,10 +99,15 @@ def genptr_decl(f, tag, regtype, regid, regno):
             hex_common.bad_register(regtype, regid)
     elif regtype == "M":
         if regid == "u":
-            f.write(f"    const int {regtype}{regid}N = " f"insn->regno[{regno}];\n")
             f.write(
-                f"    TCGv {regtype}{regid}V = hex_gpr[{regtype}{regid}N + "
-                "HEX_REG_M0];\n"
+                f"    const int {regN} = insn->regno[{regno}] + HEX_REG_M0;\n"
+            )
+            f.write(
+                f"    TCGv {regtype}{regid}V = hex_gpr[{regN}];\n"
+            )
+            f.write(
+                f"    TCGv CS G_GNUC_UNUSED = "
+                f"hex_gpr[{regN} - HEX_REG_M0 + HEX_REG_CS0];\n"
             )
         else:
             hex_common.bad_register(regtype, regid)
@@ -528,7 +533,7 @@ def gen_tcg_func(f, tag, regs, imms):
             ):
                 declared.append(f"{regtype}{regid}V")
                 if regtype == "M":
-                    declared.append(f"{regtype}{regid}N")
+                    declared.append("CS")
             elif hex_common.is_new_val(regtype, regid, tag):
                 declared.append(f"{regtype}{regid}N")
             else: