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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 v4 next 11/23] tools/nolibc/printf: Output pad characters in 16 byte chunks
Date: Mon,  2 Mar 2026 10:18:03 +0000	[thread overview]
Message-ID: <20260302101815.3043-12-david.laight.linux@gmail.com> (raw)
In-Reply-To: <20260302101815.3043-1-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 v4: no change.

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 a567b9a5c31e..5368b710c3cb 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;
 
@@ -415,10 +415,14 @@ 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


  parent reply	other threads:[~2026-03-02 10:18 UTC|newest]

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-03-02 10:17 [PATCH v4 next 00/23] Enhance printf() david.laight.linux
2026-03-02 10:17 ` [PATCH v4 next 01/23] tools/nolibc: Add _NOLIBC_OPTIMIZER_HIDE_VAR() to compiler.h david.laight.linux
2026-03-07 10:50   ` Willy Tarreau
2026-03-02 10:17 ` [PATCH v4 next 02/23] tools/nolibc/printf: Move snprintf length check to callback david.laight.linux
2026-03-07 10:48   ` Willy Tarreau
2026-03-02 10:17 ` [PATCH v4 next 03/23] selftests/nolibc: Return correct value when printf test fails david.laight.linux
2026-03-02 10:17 ` [PATCH v4 next 04/23] selftests/nolibc: check vsnprintf() output buffer before the length david.laight.linux
2026-03-02 10:17 ` [PATCH v4 next 05/23] selftests/nolibc: Use length of 'expected' string to check snprintf() output david.laight.linux
2026-03-02 10:17 ` [PATCH v4 next 06/23] selftests/nolibc: Check that snprintf() doesn't write beyond the buffer end david.laight.linux
2026-03-02 10:17 ` [PATCH v4 next 07/23] selftests/nolibc: Let EXPECT_VFPRINTF() tests be skipped david.laight.linux
2026-03-02 10:18 ` [PATCH 08/23] selftests/nolibc: Rename w to written in expect_vfprintf() david.laight.linux
2026-03-02 10:18 ` [PATCH v4 next 09/23] tools/nolibc: Implement strerror() in terms of strerror_r() david.laight.linux
2026-03-07 10:18   ` Willy Tarreau
2026-03-07 11:31     ` David Laight
2026-03-07 11:37       ` Willy Tarreau
2026-03-07 16:55         ` David Laight
2026-03-07 17:17           ` Willy Tarreau
2026-03-02 10:18 ` [PATCH v4 next 10/23] tools/nolibc: Rename the 'errnum' parameter to strerror() david.laight.linux
2026-03-07 10:19   ` Willy Tarreau
2026-03-02 10:18 ` david.laight.linux [this message]
2026-03-02 10:18 ` [PATCH 12/23] tools/nolibc/printf: Simplify __nolibc_printf() david.laight.linux
2026-03-02 10:18 ` [PATCH v4 next 13/23] tools/nolibc/printf: Use goto and reduce indentation david.laight.linux
2026-03-07 10:30   ` Willy Tarreau
2026-03-02 10:18 ` [PATCH 14/23] tools/nolibc/printf: Use bit-masks to hold requested flag, length and conversion chars david.laight.linux
2026-03-02 10:18 ` [PATCH v4 next 15/23] tools/nolibc/printf: Add support for length modifiers tzqL and formats iX david.laight.linux
2026-03-02 10:18 ` [PATCH v4 next 16/23] tools/nolibc/printf: Handle "%s" with the numeric formats david.laight.linux
2026-03-07 10:32   ` Willy Tarreau
2026-03-02 10:18 ` [PATCH 17/23] tools/nolibc/printf: Prepend sign to converted number david.laight.linux
2026-03-07 10:40   ` Willy Tarreau
2026-03-02 10:18 ` [PATCH v4 next 18/23] tools/nolibc/printf: Add support for conversion flags space and plus david.laight.linux
2026-03-07 10:46   ` Willy Tarreau
2026-03-02 10:18 ` [PATCH v4 next 19/23] tools/nolibc/printf: Special case 0 and add support for %#x david.laight.linux
2026-03-07 10:46   ` Willy Tarreau
2026-03-02 10:18 ` [PATCH v4 next 20/23] tools/nolibc/printf: Add support for left aligning fields david.laight.linux
2026-03-07 10:46   ` Willy Tarreau
2026-03-02 10:18 ` [PATCH v4 next 21/23] tools/nolibc/printf: Add support for zero padding and field precision david.laight.linux
2026-03-02 10:18 ` [PATCH v4 next 22/23] tools/nolibc/printf: Add support for octal output david.laight.linux
2026-03-07 10:45   ` Willy Tarreau
2026-03-02 10:18 ` [PATCH v4 next 23/23] selftests/nolibc: Use printf variable field widths and precisions david.laight.linux
2026-03-07 10:53 ` [PATCH v4 next 00/23] Enhance printf() Willy Tarreau
2026-03-07 18:02 ` Thomas Weißschuh
2026-03-07 22:03   ` David Laight
2026-03-07 22:20     ` Thomas Weißschuh
2026-03-08  9:23   ` Willy Tarreau

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