[PATCH] RX add control register PC

[Darius Galis]

Hello,

The following patch is adding the PC control register.
It also updates the __builtin_rx_mvfc() function, since
according to the documentation, the PC register cannot be specified
as dest.
The regression was tested with the following command:

make -k check-gcc RUNTESTFLAGS=--target_board=rx-sim

There were no additionals failures.

Please let me know if this is OK, Thank you!
Darius Galis

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index b834a2c..3436c25 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2020-08-17  Darius Galis  <darius.ga...@cyberthorstudios.com>
+
+       * config/rx/rx.md (CTRLREG_PC): Add.
+       * config/rx/rx.c (CTRLREG_PC): Add
+       (rx_expand_builtin_mvtc): Add warning: PC register cannot
+       be used as dest.
+
 2020-08-03  Jonathan Wakely  <jwak...@redhat.com>
 
 	* doc/cpp.texi (Variadic Macros): Use the exact ... token in
diff --git a/gcc/config/rx/rx.c b/gcc/config/rx/rx.c
index 151ad39..1cc88d9 100644
--- a/gcc/config/rx/rx.c
+++ b/gcc/config/rx/rx.c
@@ -639,6 +639,7 @@ rx_print_operand (FILE * file, rtx op, int letter)
       switch (INTVAL (op))
        {
        case CTRLREG_PSW:   fprintf (file, "psw"); break;
+       case CTRLREG_PC:    fprintf (file, "pc"); break;
        case CTRLREG_USP:   fprintf (file, "usp"); break;
        case CTRLREG_FPSW:  fprintf (file, "fpsw"); break;
        case CTRLREG_BPSW:  fprintf (file, "bpsw"); break;
@@ -2474,6 +2475,14 @@ rx_expand_builtin_mvtc (tree exp)
   if (! REG_P (arg2))
     arg2 = force_reg (SImode, arg2);
 
+  if (INTVAL(arg1) == 1/*PC*/)
+  {
+       warning (0, "invalid control register for mvtc : %d - using 'psw'",
+               (int) INTVAL (arg1));
+       arg1 = const0_rtx;
+  }
+
+
   emit_insn (gen_mvtc (arg1, arg2));
 
   return NULL_RTX;
diff --git a/gcc/config/rx/rx.md b/gcc/config/rx/rx.md
index df08a9e..0739f58 100644
--- a/gcc/config/rx/rx.md
+++ b/gcc/config/rx/rx.md
@@ -77,6 +77,7 @@
    (UNSPEC_PID_ADDR       52)
 
    (CTRLREG_PSW		    0)
+   (CTRLREG_PC                     1)
    (CTRLREG_USP                    2)
    (CTRLREG_FPSW           3)
    (CTRLREG_BPSW           8)

--
Ing. Darius Galiș
Software Engineer - CyberTHOR Studios Ltd.