From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
To: libc-alpha@sourceware.org
Cc: Richard Henderson <rth@twiddle.net>
Subject: [PATCH v5 13/17] hppa: Add string-fzb.h and string-fzi.h
Date: Mon, 19 Sep 2022 16:59:16 -0300 [thread overview]
Message-ID: <20220919195920.956393-14-adhemerval.zanella@linaro.org> (raw)
In-Reply-To: <20220919195920.956393-1-adhemerval.zanella@linaro.org>
From: Richard Henderson <rth@twiddle.net>
Use UXOR,SBZ to test for a zero byte within a word. While we can
get semi-decent code out of asm-goto, we would do slightly better
with a compiler builtin.
For index_zero et al, sequential testing of bytes is less expensive than
any tricks that involve a count-leading-zeros insn that we don't have.
Checked on hppa-linux-gnu.
---
sysdeps/hppa/string-fzb.h | 69 +++++++++++++++++++
sysdeps/hppa/string-fzi.h | 135 ++++++++++++++++++++++++++++++++++++++
2 files changed, 204 insertions(+)
create mode 100644 sysdeps/hppa/string-fzb.h
create mode 100644 sysdeps/hppa/string-fzi.h
diff --git a/sysdeps/hppa/string-fzb.h b/sysdeps/hppa/string-fzb.h
new file mode 100644
index 0000000000..dc02757522
--- /dev/null
+++ b/sysdeps/hppa/string-fzb.h
@@ -0,0 +1,69 @@
+/* Zero byte detection, boolean. HPPA 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)
+{
+ _Static_assert (sizeof (op_t) == 4, "64-bit not supported");
+
+ /* It's more useful to expose a control transfer to the compiler
+ than to expose a proper boolean result. */
+ asm goto ("uxor,sbz %%r0,%0,%%r0\n\t"
+ "b,n %l1" : : "r"(x) : : nbz);
+ return 1;
+ nbz:
+ return 0;
+}
+
+/* Likewise, but for byte equality between X1 and X2. */
+
+static inline _Bool
+has_eq (op_t x1, op_t x2)
+{
+ _Static_assert (sizeof (op_t) == 4, "64-bit not supported");
+
+ asm goto ("uxor,sbz %0,%1,%%r0\n\t"
+ "b,n %l2" : : "r"(x1), "r"(x2) : : nbz);
+ return 1;
+ nbz:
+ return 0;
+}
+
+/* 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)
+{
+ _Static_assert (sizeof (op_t) == 4, "64-bit not supported");
+
+ asm goto ("uxor,sbz %%r0,%0,%%r0\n\t"
+ "uxor,nbz %0,%1,%%r0\n\t"
+ "b,n %l2" : : "r"(x1), "r"(x2) : : sbz);
+ return 0;
+ sbz:
+ return 1;
+}
+
+#endif /* _STRING_FZB_H */
diff --git a/sysdeps/hppa/string-fzi.h b/sysdeps/hppa/string-fzi.h
new file mode 100644
index 0000000000..2b8747ddbd
--- /dev/null
+++ b/sysdeps/hppa/string-fzi.h
@@ -0,0 +1,135 @@
+/* string-fzi.h -- zero byte detection; indexes. HPPA 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_FZI_H
+#define _STRING_FZI_H 1
+
+#include <string-optype.h>
+
+/* Given a word X that is known to contain a zero byte, return the
+ index of the first such within the long in memory order. */
+
+static inline unsigned int
+index_first_zero (op_t x)
+{
+ unsigned int ret;
+
+ _Static_assert (sizeof (op_t) == 4, "64-bit not supported");
+
+ /* Since we have no clz insn, direct tests of the bytes is faster
+ than loading up the constants to do the masking. */
+ asm ("extrw,u,<> %1,23,8,%%r0\n\t"
+ "ldi 2,%0\n\t"
+ "extrw,u,<> %1,15,8,%%r0\n\t"
+ "ldi 1,%0\n\t"
+ "extrw,u,<> %1,7,8,%%r0\n\t"
+ "ldi 0,%0"
+ : "=r"(ret) : "r"(x), "0"(3));
+
+ return ret;
+}
+
+/* Similarly, but perform the search for byte equality between X1 and X2. */
+
+static inline unsigned int
+index_first_eq (op_t x1, op_t x2)
+{
+ return index_first_zero (x1 ^ x2);
+}
+
+/* Similarly, but perform the search for zero within X1 or
+ equality between X1 and X2. */
+
+static inline unsigned int
+index_first_zero_eq (op_t x1, op_t x2)
+{
+ unsigned int ret;
+
+ _Static_assert (sizeof (op_t) == 4, "64-bit not supported");
+
+ /* Since we have no clz insn, direct tests of the bytes is faster
+ than loading up the constants to do the masking. */
+ asm ("extrw,u,= %1,23,8,%%r0\n\t"
+ "extrw,u,<> %2,23,8,%%r0\n\t"
+ "ldi 2,%0\n\t"
+ "extrw,u,= %1,15,8,%%r0\n\t"
+ "extrw,u,<> %2,15,8,%%r0\n\t"
+ "ldi 1,%0\n\t"
+ "extrw,u,= %1,7,8,%%r0\n\t"
+ "extrw,u,<> %2,7,8,%%r0\n\t"
+ "ldi 0,%0"
+ : "=r"(ret) : "r"(x1), "r"(x1 ^ x2), "0"(3));
+
+ return ret;
+}
+
+/* Similarly, but perform the search for zero within X1 or
+ inequality between X1 and X2. */
+
+static inline unsigned int
+index_first_zero_ne (op_t x1, op_t x2)
+{
+ unsigned int ret;
+
+ _Static_assert (sizeof (op_t) == 4, "64-bit not supported");
+
+ /* Since we have no clz insn, direct tests of the bytes is faster
+ than loading up the constants to do the masking. */
+ asm ("extrw,u,<> %2,23,8,%%r0\n\t"
+ "extrw,u,<> %1,23,8,%%r0\n\t"
+ "ldi 2,%0\n\t"
+ "extrw,u,<> %2,15,8,%%r0\n\t"
+ "extrw,u,<> %1,15,8,%%r0\n\t"
+ "ldi 1,%0\n\t"
+ "extrw,u,<> %2,7,8,%%r0\n\t"
+ "extrw,u,<> %1,7,8,%%r0\n\t"
+ "ldi 0,%0"
+ : "=r"(ret) : "r"(x1), "r"(x1 ^ x2), "0"(3));
+
+ return ret;
+}
+
+/* Similarly, but search for the last zero within X. */
+
+static inline unsigned int
+index_last_zero (op_t x)
+{
+ unsigned int ret;
+
+ _Static_assert (sizeof (op_t) == 4, "64-bit not supported");
+
+ /* Since we have no ctz insn, direct tests of the bytes is faster
+ than loading up the constants to do the masking. */
+ asm ("extrw,u,<> %1,15,8,%%r0\n\t"
+ "ldi 1,%0\n\t"
+ "extrw,u,<> %1,23,8,%%r0\n\t"
+ "ldi 2,%0\n\t"
+ "extrw,u,<> %1,31,8,%%r0\n\t"
+ "ldi 3,%0"
+ : "=r"(ret) : "r"(x), "0"(0));
+
+ return ret;
+}
+
+static inline unsigned int
+index_last_eq (op_t x1, op_t x2)
+{
+ return index_last_zero (x1 ^ x2);
+}
+
+#endif /* _STRING_FZI_H */
--
2.34.1
next prev parent reply other threads:[~2022-09-19 19:59 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-19 19:59 [PATCH v5 00/17] Improve generic string routines Adhemerval Zanella
2022-09-19 19:59 ` [PATCH v5 01/17] Parameterize op_t from memcopy.h Adhemerval Zanella
2022-09-19 19:59 ` [PATCH v5 02/17] Parameterize OP_T_THRES " Adhemerval Zanella
2022-09-20 10:49 ` Carlos O'Donell
2022-09-19 19:59 ` [PATCH v5 03/17] Add string-maskoff.h generic header Adhemerval Zanella
2022-09-20 11:43 ` Carlos O'Donell
2022-09-22 17:31 ` Adhemerval Zanella Netto
2023-01-05 22:49 ` Noah Goldstein
2023-01-05 23:26 ` Alejandro Colomar
2023-01-09 18:19 ` Adhemerval Zanella Netto
2023-01-09 18:02 ` Adhemerval Zanella Netto
2022-09-19 19:59 ` [PATCH v5 04/17] Add string vectorized find and detection functions Adhemerval Zanella
2023-01-05 22:53 ` Noah Goldstein
2023-01-09 18:51 ` Adhemerval Zanella Netto
2023-01-05 23:04 ` Noah Goldstein
2023-01-09 19:34 ` Adhemerval Zanella Netto
2022-09-19 19:59 ` [PATCH v5 05/17] string: Improve generic strlen Adhemerval Zanella
2022-09-19 19:59 ` [PATCH v5 06/17] string: Improve generic strnlen Adhemerval Zanella
2022-09-19 19:59 ` [PATCH v5 07/17] string: Improve generic strchr Adhemerval Zanella
2023-01-05 23:09 ` Noah Goldstein
2023-01-05 23:19 ` Noah Goldstein
2023-01-09 19:39 ` Adhemerval Zanella Netto
2022-09-19 19:59 ` [PATCH v5 08/17] string: Improve generic strchrnul Adhemerval Zanella
2023-01-05 23:17 ` Noah Goldstein
2023-01-09 20:35 ` Adhemerval Zanella Netto
2023-01-09 20:49 ` Richard Henderson
2023-01-09 20:59 ` Noah Goldstein
2023-01-09 21:01 ` Noah Goldstein
2023-01-09 23:33 ` Richard Henderson
2023-01-10 14:18 ` Adhemerval Zanella Netto
2023-01-10 16:24 ` Richard Henderson
2023-01-10 17:16 ` Noah Goldstein
2023-01-10 18:19 ` Adhemerval Zanella Netto
2023-01-10 17:17 ` Noah Goldstein
2023-01-10 18:16 ` Adhemerval Zanella Netto
2022-09-19 19:59 ` [PATCH v5 09/17] string: Improve generic strcmp Adhemerval Zanella
2022-09-19 19:59 ` [PATCH v5 10/17] string: Improve generic memchr Adhemerval Zanella
2023-01-05 23:47 ` Noah Goldstein
2023-01-09 20:50 ` Adhemerval Zanella Netto
2023-01-05 23:49 ` Noah Goldstein
2023-01-09 20:51 ` Adhemerval Zanella Netto
2023-01-09 21:26 ` Noah Goldstein
2023-01-10 14:33 ` Adhemerval Zanella Netto
2022-09-19 19:59 ` [PATCH v5 11/17] string: Improve generic memrchr Adhemerval Zanella
2023-01-05 23:51 ` Noah Goldstein
2022-09-19 19:59 ` [PATCH v5 12/17] hppa: Add memcopy.h Adhemerval Zanella
2022-09-19 19:59 ` Adhemerval Zanella [this message]
2022-09-19 19:59 ` [PATCH v5 14/17] alpha: Add string-fzb.h and string-fzi.h Adhemerval Zanella
2022-09-19 19:59 ` [PATCH v5 15/17] arm: Add string-fza.h Adhemerval Zanella
2022-09-19 19:59 ` [PATCH v5 16/17] powerpc: " Adhemerval Zanella
2022-09-19 19:59 ` [PATCH v5 17/17] sh: Add string-fzb.h Adhemerval Zanella
2022-12-05 17:07 ` [PATCH v5 00/17] Improve generic string routines Xi Ruoyao
2023-01-05 21:56 ` Adhemerval Zanella Netto
2023-01-05 23:52 ` Noah Goldstein
2023-01-06 13:43 ` Adhemerval Zanella Netto
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20220919195920.956393-14-adhemerval.zanella@linaro.org \
--to=adhemerval.zanella@linaro.org \
--cc=libc-alpha@sourceware.org \
--cc=rth@twiddle.net \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).