new file mode 100644
@@ -0,0 +1,55 @@
+/* Basic zero byte detection. Generic C 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_FZA_H
+#define _STRING_FZA_H 1
+
+#include <limits.h>
+#include <string-optype.h>
+#include <string-maskoff.h>
+
+/* The CMPBGE creates a bit mask rather than a byte mask. */
+typedef int find_t;
+
+static __always_inline find_t
+find_zero_all (op_t x)
+{
+ return __builtin_alpha_cmpbge (0, x);
+}
+
+static __always_inline find_t
+find_eq_all (op_t x1, op_t x2)
+{
+ return find_zero_all (x1 ^ x2);
+}
+
+static __always_inline find_t
+find_zero_eq_all (op_t x1, op_t x2)
+{
+ return find_zero_all (x1) | find_zero_all (x1 ^ x2);
+}
+
+/* Return the mask WORD shifted based on S_INT address value, to ignore
+ values not presented in the aligned word read. */
+static __always_inline find_t
+shift_find (find_t word, uintptr_t s)
+{
+ return word >> (s % sizeof (op_t));
+}
+
+#endif /* _STRING_FZA_H */
new file mode 100644
@@ -0,0 +1,52 @@
+/* Zero byte detection; boolean. Alpha 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>
+
+/* Note that since CMPBGE creates a bit mask rather than a byte mask,
+ we cannot simply provide a target-specific string-fza.h. */
+
+/* Determine if any byte within X is zero. This is a pure boolean test. */
+
+static __always_inline _Bool
+has_zero (op_t x)
+{
+ return __builtin_alpha_cmpbge (0, x) != 0;
+}
+
+/* Likewise, but for byte equality between X1 and X2. */
+
+static __always_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 __always_inline _Bool
+has_zero_eq (op_t x1, op_t x2)
+{
+ return has_zero (x1) | has_eq (x1, x2);
+}
+
+#endif /* _STRING_FZB_H */
new file mode 100644
@@ -0,0 +1,113 @@
+/* string-fzi.h -- zero byte detection; indices. Alpha 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
+
+#include <stdint.h>
+#include <string-optype.h>
+#include <string-fza.h>
+
+/* Note that since CMPBGE creates a bit mask rather than a byte mask,
+ we cannot simply provide a target-specific string-fza.h. */
+
+/* A subroutine for the index_zero functions. Given a bitmask C,
+ return the index of the first bit set in memory order. */
+static __always_inline unsigned int
+index_first (find_t c)
+{
+#ifdef __alpha_cix__
+ return __builtin_ctzl (c);
+#else
+ c = c & -c;
+ return (c & 0xf0 ? 4 : 0) + (c & 0xcc ? 2 : 0) + (c & 0xaa ? 1 : 0);
+#endif
+}
+
+/* Similarly, but return the (memory order) index of the last bit
+ that is non-zero. Note that only the least 8 bits may be nonzero. */
+
+static __always_inline unsigned int
+index_last_ (unsigned long int x)
+{
+#ifdef __alpha_cix__
+ return __builtin_clzl (x) ^ 63;
+#else
+ unsigned r = 0;
+ if (x & 0xf0)
+ r += 4;
+ if (x & (0xc << r))
+ r += 2;
+ if (x & (0x2 << r))
+ r += 1;
+ return r;
+#endif
+}
+
+/* Given a word X that is known to contain a zero byte, return the
+ index of the first such within the word in memory order. */
+
+static __always_inline unsigned int
+index_first_zero (op_t x)
+{
+ return index_first (__builtin_alpha_cmpbge (0, x));
+}
+
+/* Similarly, but perform the test 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)
+{
+ return index_first (__builtin_alpha_cmpbge (0, x1)
+ | __builtin_alpha_cmpbge (0, x1 ^ x2));
+}
+
+/* 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)
+{
+ return index_first (__builtin_alpha_cmpbge (0, x1)
+ | (__builtin_alpha_cmpbge (0, x1 ^ x2) ^ 0xFF));
+}
+
+/* Similarly, but search for the last zero within X. */
+
+static __always_inline unsigned int
+index_last_zero (op_t x)
+{
+ return index_last_ (__builtin_alpha_cmpbge (0, x));
+}
+
+static __always_inline unsigned int
+index_last_eq (op_t x1, op_t x2)
+{
+ return index_last_zero (x1 ^ x2);
+}
+
+#endif /* _STRING_FZI_H */
@@ -45,7 +45,7 @@ ctz (op_t c)
the (memory order) index of the first byte (in memory order) that is
non-zero. */
static __always_inline unsigned int
-index_first (op_t c)
+index_first (find_t c)
{
int r;
if (__BYTE_ORDER == __LITTLE_ENDIAN)
From: Richard Henderson <richard.henderson@linaro.org> While alpha has the more important string functions in assembly, there are still a few for find the generic routines are used. Use the CMPBGE insn, via the builtin, for testing of zeros. Use a simplified expansion of __builtin_ctz when the insn isn't available. Checked on alpha-linux-gnu. Co-authored-by: Adhemerval Zanella <adhemerval.zanella@linaro.org> --- sysdeps/alpha/string-fza.h | 55 +++++++++++++++++ sysdeps/alpha/string-fzb.h | 52 ++++++++++++++++ sysdeps/alpha/string-fzi.h | 113 +++++++++++++++++++++++++++++++++++ sysdeps/generic/string-fzi.h | 2 +- 4 files changed, 221 insertions(+), 1 deletion(-) create mode 100644 sysdeps/alpha/string-fza.h create mode 100644 sysdeps/alpha/string-fzb.h create mode 100644 sysdeps/alpha/string-fzi.h