[PATCH 17/17] sh: Add string-fzb.h

[Adhemerval Zanella]

Use the SH cmp/str on has_{zero,eq,zero_eq}.

Checked on sh4-linux-gnu.
---
 sysdeps/sh/string-fzb.h | 53 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)
 create mode 100644 sysdeps/sh/string-fzb.h

diff --git a/sysdeps/sh/string-fzb.h b/sysdeps/sh/string-fzb.h
new file mode 100644
index 0000000000..62823b4d0e
--- /dev/null
+++ b/sysdeps/sh/string-fzb.h
@@ -0,0 +1,53 @@
+/* Zero byte detection; boolean.  SH4 version.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef STRING_FZB_H
+#define STRING_FZB_H 1
+
+#include <string-optype.h>
+
+/* Determine if any byte within X is zero.  This is a pure boolean test.  */
+
+static inline _Bool
+has_zero (op_t x)
+{
+  op_t zero = 0x0, ret;
+  asm volatile ("cmp/str %1,%2\n"
+		"movt %0\n"
+		: "=r" (ret)
+		: "r" (zero), "r" (x));
+  return ret;
+}
+
+/* Likewise, but for byte equality between X1 and X2.  */
+
+static inline _Bool
+has_eq (op_t x1, op_t x2)
+{
+  return has_zero (x1 ^ x2);
+}
+
+/* Likewise, but for zeros in X1 and equal bytes between X1 and X2.  */
+
+static inline _Bool
+has_zero_eq (op_t x1, op_t x2)
+{
+  return has_zero (x1) | has_eq (x1, x2);
+}
+
+#endif /* STRING_FZB_H */
-- 
2.34.1