[PATCH 1/5] xtensa: Simplify EXTUI instruction maskimm validations

[Takayuki 'January June' Suwa via Gcc-patches]

No functional changes.

gcc/ChangeLog:
        * gcc/config/xtensa/predicates.md (extui_fldsz_operand): Simplify.
        * gcc/config/xtensa/xtensa.cc (xtensa_mask_immediate, print_operand):
        Ditto.
---
 gcc/config/xtensa/predicates.md |  2 +-
 gcc/config/xtensa/xtensa.cc     | 24 +++---------------------
 2 files changed, 4 insertions(+), 22 deletions(-)

diff --git a/gcc/config/xtensa/predicates.md 
b/gcc/config/xtensa/predicates.md
index 01226a2b3c7..daea63b182c 100644
--- a/gcc/config/xtensa/predicates.md
+++ b/gcc/config/xtensa/predicates.md
@@ -55,7 +55,7 @@

 (define_predicate "extui_fldsz_operand"
   (and (match_code "const_int")
-       (match_test "xtensa_mask_immediate ((1 << INTVAL (op)) - 1)")))
+       (match_test "IN_RANGE (INTVAL (op), 1, 16)")))

 (define_predicate "sext_operand"
   (if_then_else (match_test "TARGET_SEXT")
diff --git a/gcc/config/xtensa/xtensa.cc b/gcc/config/xtensa/xtensa.cc
index 7023badf0e2..a1f77b2bd35 100644
--- a/gcc/config/xtensa/xtensa.cc
+++ b/gcc/config/xtensa/xtensa.cc
@@ -456,19 +456,7 @@ xtensa_b4constu (HOST_WIDE_INT v)
 bool
 xtensa_mask_immediate (HOST_WIDE_INT v)
 {
-#define MAX_MASK_SIZE 16
-  int mask_size;
-
-  for (mask_size = 1; mask_size <= MAX_MASK_SIZE; mask_size++)
-    {
-      if ((v & 1) == 0)
-       return false;
-      v = v >> 1;
-      if (v == 0)
-       return true;
-    }
-
-  return false;
+  return IN_RANGE (exact_log2 (v + 1), 1, 16);
 }


@@ -2430,17 +2418,11 @@ print_operand (FILE *file, rtx x, int letter)
     case 'K':
       if (GET_CODE (x) == CONST_INT)
        {
-         int num_bits = 0;
          unsigned val = INTVAL (x);
-         while (val & 1)
-           {
-             num_bits += 1;
-             val = val >> 1;
-           }
-         if ((val != 0) || (num_bits == 0) || (num_bits > 16))
+         if (!xtensa_mask_immediate (val))
            fatal_insn ("invalid mask", x);

-         fprintf (file, "%d", num_bits);
+         fprintf (file, "%d", floor_log2 (val + 1));
        }
       else
        output_operand_lossage ("invalid %%K value");
--
2.20.1