diff options
| -rw-r--r-- | auto/make | 2 | ||||
| -rw-r--r-- | src/nxt_unit_bit.h | 64 |
2 files changed, 66 insertions, 0 deletions
@@ -406,6 +406,7 @@ libunit-install: $NXT_BUILD_DIR/lib/$NXT_LIB_UNIT_STATIC test -d \$(DESTDIR)$NXT_INCLUDEDIR \ || install -d \$(DESTDIR)$NXT_INCLUDEDIR install -p -m u=rw,go=r src/nxt_unit.h \ + src/nxt_unit_bit.h \ src/nxt_unit_cdefs.h \ src/nxt_unit_field.h \ src/nxt_unit_request.h \ @@ -424,6 +425,7 @@ libunit-uninstall: rm -f \$(DESTDIR)$NXT_PKGCONFIGDIR/unit.pc @rmdir -p \$(DESTDIR)$NXT_PKGCONFIGDIR 2>/dev/null || true rm -f \$(DESTDIR)$NXT_INCLUDEDIR/nxt_unit.h \ + \$(DESTDIR)$NXT_INCLUDEDIR/nxt_unit_bit.h \ \$(DESTDIR)$NXT_INCLUDEDIR/nxt_unit_cdefs.h \ \$(DESTDIR)$NXT_INCLUDEDIR/nxt_unit_field.h \ \$(DESTDIR)$NXT_INCLUDEDIR/nxt_unit_request.h \ diff --git a/src/nxt_unit_bit.h b/src/nxt_unit_bit.h new file mode 100644 index 00000000..6b43b7c0 --- /dev/null +++ b/src/nxt_unit_bit.h @@ -0,0 +1,64 @@ +/* + * Copyright (C) 2022-2023, Alejandro Colomar <alx@kernel.org> + * Copyright (C) NGINX, Inc. + */ + +#ifndef _NXT_UNIT_BIT_H_INCLUDED_ +#define _NXT_UNIT_BIT_H_INCLUDED_ + + +#include <limits.h> + + +/* C23 <stdbit.h> stuff */ +nxt_inline unsigned long nxt_bit_ceil_ul(unsigned long x); +nxt_inline unsigned long nxt_bit_ceil_wrap_ul(unsigned long x); +nxt_inline int nxt_bit_width_ul(unsigned long x); +nxt_inline int nxt_leading_zeros_ul(unsigned long x); +nxt_inline int nxt_trailing_zeros_ul(unsigned long x); + + +nxt_inline unsigned long +nxt_bit_ceil_ul(unsigned long x) +{ + return 1 + (ULONG_MAX >> nxt_leading_zeros_ul(x)); +} + + +nxt_inline unsigned long +nxt_bit_ceil_wrap_ul(unsigned long x) +{ + return (x == 0) ? 0 : nxt_bit_ceil_ul(x); +} + + +nxt_inline int +nxt_bit_width_ul(unsigned long x) +{ + return (x == 0) ? 0 : nxt_trailing_zeros_ul(nxt_bit_ceil_ul(x)); +} + + +nxt_inline int +nxt_leading_zeros_ul(unsigned long x) +{ + if (x == 0) { + return sizeof(unsigned long) * CHAR_BIT; + } + + return __builtin_clzl(x); +} + + +nxt_inline int +nxt_trailing_zeros_ul(unsigned long x) +{ + if (x == 0) { + return sizeof(unsigned long) * CHAR_BIT; + } + + return __builtin_ctzl(x); +} + + +#endif /* _NXT_UNIT_BIT_H_INCLUDED_ */ |