From: david.laight.linux@gmail.com
To: "Willy Tarreau" <w@1wt.eu>,
"Thomas Weißschuh" <linux@weissschuh.net>,
linux-kernel@vger.kernel.org, "Cheng Li" <lechain@gmail.com>
Cc: David Laight <david.laight.linux@gmail.com>
Subject: [PATCH v3 next 08/17] tools/nolibc/printf: Output pad characters in 16 byte chunks
Date: Mon, 23 Feb 2026 10:17:26 +0000 [thread overview]
Message-ID: <20260223101735.2922-9-david.laight.linux@gmail.com> (raw)
In-Reply-To: <20260223101735.2922-1-david.laight.linux@gmail.com>
From: David Laight <david.laight.linux@gmail.com>
Simple to do and saves calls to the callback function.
Change variables written, width and len to 'signed int' to get
better code.
Acked-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: David Laight <david.laight.linux@gmail.com>
---
For v3:
- Change to signed variables here rather than a later patch.
tools/include/nolibc/stdio.h | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)
diff --git a/tools/include/nolibc/stdio.h b/tools/include/nolibc/stdio.h
index 5c8f233336b9..ea6c514c4b7a 100644
--- a/tools/include/nolibc/stdio.h
+++ b/tools/include/nolibc/stdio.h
@@ -312,8 +312,8 @@ int __nolibc_printf(__nolibc_printf_cb cb, void *state, const char *fmt, va_list
{
char escape, lpref, ch;
unsigned long long v;
- unsigned int written, width;
- size_t len, ofs;
+ int written, width, len;
+ size_t ofs;
char outbuf[21];
const char *outstr;
@@ -411,10 +411,14 @@ int __nolibc_printf(__nolibc_printf_cb cb, void *state, const char *fmt, va_list
outstr = fmt;
len = ofs - 1;
flush_str:
- while (width-- > len) {
- if (cb(state, " ", 1) != 0)
+ width -= len;
+ while (width > 0) {
+ /* Output pad in 16 byte blocks with the small block first. */
+ int pad_len = ((width - 1) & 15) + 1;
+ width -= pad_len;
+ written += pad_len;
+ if (cb(state, " ", pad_len) != 0)
return -1;
- written += 1;
}
if (cb(state, outstr, len) != 0)
return -1;
--
2.39.5
next prev parent reply other threads:[~2026-02-23 10:35 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-23 10:17 [PATCH v3 next 00/17] Enhance printf() david.laight.linux
2026-02-23 10:17 ` [PATCH v3 next 01/17] tools/nolibc: Add _NOLIBC_OPTIMIZER_HIDE_VAR() to compiler.h david.laight.linux
2026-02-25 21:25 ` Thomas Weißschuh
2026-02-25 22:17 ` David Laight
2026-02-25 22:24 ` Thomas Weißschuh
2026-02-23 10:17 ` [PATCH v3 next 02/17] tools/nolibc: Optimise and common up the number to ascii functions david.laight.linux
2026-02-25 21:40 ` Thomas Weißschuh
2026-02-25 22:09 ` David Laight
2026-02-23 10:17 ` [PATCH v3 next 03/17] selftests/nolibc: Fix build with host headers and libc david.laight.linux
2026-02-25 21:24 ` Thomas Weißschuh
2026-02-23 10:17 ` [PATCH v3 next 04/17] selftests/nolibc: Improve reporting of vfprintf() errors david.laight.linux
2026-02-25 21:56 ` Thomas Weißschuh
2026-02-26 10:12 ` David Laight
2026-02-26 21:39 ` Thomas Weißschuh
2026-02-23 10:17 ` [PATCH v3 next 05/17] tools/nolibc: Implement strerror() in terms of strerror_r() david.laight.linux
2026-02-25 22:09 ` Thomas Weißschuh
2026-02-25 22:58 ` David Laight
2026-02-23 10:17 ` [PATCH v3 next 06/17] tools/nolibc/printf: Change variables 'c' to 'ch' and 'tmpbuf[]' to 'outbuf[]' david.laight.linux
2026-02-25 22:23 ` Thomas Weißschuh
2026-02-23 10:17 ` [PATCH v3 next 07/17] tools/nolibc/printf: Move snprintf length check to callback david.laight.linux
2026-02-25 22:37 ` Thomas Weißschuh
2026-02-25 23:12 ` David Laight
2026-02-26 21:29 ` Thomas Weißschuh
2026-02-26 22:11 ` David Laight
2026-02-23 10:17 ` david.laight.linux [this message]
2026-02-23 10:17 ` [PATCH v3 next 09/17] tools/nolibc/printf: Simplify __nolibc_printf() david.laight.linux
2026-02-23 10:17 ` [PATCH v3 next 10/17] tools/nolibc/printf: Use goto and reduce indentation david.laight.linux
2026-02-23 10:17 ` [PATCH v3 next 11/17] tools/nolibc/printf: Use bit-masks to hold requested flag, length and conversion chars david.laight.linux
2026-02-23 10:17 ` [PATCH v3 next 12/17] tools/nolibc/printf: Handle "%s" with the numeric formats david.laight.linux
2026-02-23 10:17 ` [PATCH v3 next 13/17] tools/nolibc/printf: Add support for conversion flags david.laight.linux
2026-02-23 10:17 ` [PATCH v3 next 14/17] tools/nolibc/printf: Add support for left aligning fields david.laight.linux
2026-02-23 10:17 ` [PATCH v3 next 15/17] tools/nolibc/printf: Add support for zero padding and field precision david.laight.linux
2026-02-23 10:17 ` [PATCH v3 next 16/17] tools/nolibc/printf: Add support for octal output david.laight.linux
2026-02-23 10:17 ` [PATCH v3 next 17/17] selftests/nolibc: Use printf variable field widths and precisions david.laight.linux
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