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* [glibc/azanella/generic-strings] hppa: Add string-fzb.h and string-fzi.h
@ 2023-01-13 20:03 Adhemerval Zanella
0 siblings, 0 replies; only message in thread
From: Adhemerval Zanella @ 2023-01-13 20:03 UTC (permalink / raw)
To: glibc-cvs
https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=bd1edea1835fb2ae0d9925019818b8bc05517209
commit bd1edea1835fb2ae0d9925019818b8bc05517209
Author: Richard Henderson <richard.henderson@linaro.org>
Date: Tue Jan 10 18:01:02 2023 -0300
hppa: Add string-fzb.h and string-fzi.h
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.
Diff:
---
sysdeps/hppa/string-fzb.h | 70 ++++++++++++++++++++++++++
sysdeps/hppa/string-fzc.h | 124 ++++++++++++++++++++++++++++++++++++++++++++++
sysdeps/hppa/string-fzi.h | 63 +++++++++++++++++++++++
3 files changed, 257 insertions(+)
diff --git a/sysdeps/hppa/string-fzb.h b/sysdeps/hppa/string-fzb.h
new file mode 100644
index 0000000000..865e548492
--- /dev/null
+++ b/sysdeps/hppa/string-fzb.h
@@ -0,0 +1,70 @@
+/* Zero byte detection, boolean. HPPA version.
+ Copyright (C) 2023 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 <sys/cdefs.h>
+#include <string-optype.h>
+
+/* Determine if any byte within X is zero. This is a pure boolean test. */
+
+static __always_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 __always_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 __always_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-fzc.h b/sysdeps/hppa/string-fzc.h
new file mode 100644
index 0000000000..8ff3416b41
--- /dev/null
+++ b/sysdeps/hppa/string-fzc.h
@@ -0,0 +1,124 @@
+/* string-fzc.h -- zero byte detection with 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_FZC_H
+#define _STRING_FZC_H 1
+
+#include <string-optype.h>
+
+_Static_assert (sizeof (op_t) == 4, "64-bit not supported");
+
+/* 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 __always_inline unsigned int
+index_first_zero (op_t x)
+{
+ unsigned int ret;
+
+ /* 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 __always_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 __always_inline unsigned int
+index_first_zero_eq (op_t x1, op_t x2)
+{
+ unsigned int ret;
+
+ /* 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 __always_inline unsigned int
+index_first_zero_ne (op_t x1, op_t x2)
+{
+ unsigned int ret;
+
+ /* 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 __always_inline unsigned int
+index_last_zero (op_t x)
+{
+ unsigned int ret;
+
+ /* 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 __always_inline unsigned int
+index_last_eq (op_t x1, op_t x2)
+{
+ return index_last_zero (x1 ^ x2);
+}
+
+#endif /* _STRING_FZC_H */
diff --git a/sysdeps/hppa/string-fzi.h b/sysdeps/hppa/string-fzi.h
new file mode 100644
index 0000000000..b560fa1a89
--- /dev/null
+++ b/sysdeps/hppa/string-fzi.h
@@ -0,0 +1,63 @@
+/* string-fzi.h -- zero byte 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>
+#include <string-fza.h>
+
+_Static_assert (sizeof (op_t) == 4, "64-bit not supported");
+
+static __always_inline unsigned int
+index_first (find_t c)
+{
+ unsigned int ret;
+
+ /* 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"(c), "0"(3));
+
+ return ret;
+}
+
+static __always_inline unsigned int
+index_last (find_t c)
+{
+ unsigned int ret;
+
+ /* 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"(c), "0"(0));
+
+ return ret;
+}
+
+#endif /* _STRING_FZI_H */
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