[PATCH V2 4/7] aarch64: Add basic target_print_operand support for CONST_STRING

[Victor Do Nascimento]

Motivated by the need to print system register names in output
assembly, this patch adds the required logic to
`aarch64_print_operand' to accept rtxs of type CONST_STRING and
process these accordingly.

Consequently, an rtx such as:

  (set (reg/i:DI 0 x0)
         (unspec:DI [(const_string ("s3_3_c13_c2_2"))])

can now be output correctly using the following output pattern when
composing `define_insn's:

  "mrs\t%x0, %1"

gcc/ChangeLog

        * gcc/config/aarch64/aarch64.cc (aarch64_print_operand): Add
        support for CONST_STRING.
---
 gcc/config/aarch64/aarch64.cc | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/gcc/config/aarch64/aarch64.cc b/gcc/config/aarch64/aarch64.cc
index 816c4b69fc8..d187e171beb 100644
--- a/gcc/config/aarch64/aarch64.cc
+++ b/gcc/config/aarch64/aarch64.cc
@@ -12430,6 +12430,12 @@ aarch64_print_operand (FILE *f, rtx x, int code)
 
       switch (GET_CODE (x))
        {
+       case CONST_STRING:
+         {
+           const char *output_op = XSTR (x, 0);
+           asm_fprintf (f, "%s", output_op);
+           break;
+         }
        case REG:
          if (aarch64_sve_data_mode_p (GET_MODE (x)))
            {
-- 
2.41.0