From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
To: libc-alpha@sourceware.org, Joe Simmons-Talbott <josimmon@redhat.com>
Subject: [PATCH v2 2/2] stdio: Remove __printf_fp_buffer_2 alloca usage
Date: Thu, 14 Sep 2023 11:06:39 -0300 [thread overview]
Message-ID: <20230914140639.1912983-3-adhemerval.zanella@linaro.org> (raw)
In-Reply-To: <20230914140639.1912983-1-adhemerval.zanella@linaro.org>
And replace with a scratch_buffer.
--
Changes from v1:
* Fixed stdio-common regressions.
---
stdio-common/printf_fp.c | 36 ++++++++++--------------------------
1 file changed, 10 insertions(+), 26 deletions(-)
diff --git a/stdio-common/printf_fp.c b/stdio-common/printf_fp.c
index 9ddf61fd6d..7c85edb8c9 100644
--- a/stdio-common/printf_fp.c
+++ b/stdio-common/printf_fp.c
@@ -17,12 +17,8 @@
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
-/* The gmp headers need some configuration frobs. */
-#define HAVE_ALLOCA 1
-
#include <array_length.h>
#include <libioP.h>
-#include <alloca.h>
#include <ctype.h>
#include <float.h>
#include <gmp-mparam.h>
@@ -168,11 +164,6 @@ __printf_fp_buffer_2 (struct hack_digit_param *p, struct __printf_buffer *buf,
/* General helper (carry limb). */
mp_limb_t cy;
- /* Buffer in which we produce the output. */
- char *wbuffer = NULL;
- /* Flag whether wbuffer and buffer are malloc'ed or not. */
- int buffer_malloced = 0;
-
p->expsign = 0;
if (p->special)
@@ -600,6 +591,9 @@ __printf_fp_buffer_2 (struct hack_digit_param *p, struct __printf_buffer *buf,
int dig_max;
int significant;
char spec = _tolower (info->spec);
+ struct scratch_buffer wscbuf;
+
+ scratch_buffer_init (&wscbuf);
if (spec == 'e')
{
@@ -662,7 +656,7 @@ __printf_fp_buffer_2 (struct hack_digit_param *p, struct __printf_buffer *buf,
/* Allocate buffer for output. We need two more because while rounding
it is possible that we need two more characters in front of all the
other output. If the amount of memory we have to allocate is too
- large use `malloc' instead of `alloca'. */
+ large use `malloc' instead of a static buffer. */
if (__glibc_unlikely (chars_needed >= (size_t) -1 - 2
|| chars_needed < fracdig_max))
{
@@ -671,21 +665,12 @@ __printf_fp_buffer_2 (struct hack_digit_param *p, struct __printf_buffer *buf,
__printf_buffer_mark_failed (buf);
return;
}
- size_t wbuffer_to_alloc = 2 + chars_needed;
- buffer_malloced = ! __libc_use_alloca (wbuffer_to_alloc);
- if (__builtin_expect (buffer_malloced, 0))
+ if (!scratch_buffer_set_array_size (&wscbuf, 1, 2 + chars_needed))
{
- wbuffer = malloc (wbuffer_to_alloc);
- if (wbuffer == NULL)
- {
- /* Signal an error to the caller. */
- __printf_buffer_mark_failed (buf);
- return;
- }
+ __printf_buffer_mark_failed (buf);
+ return;
}
- else
- wbuffer = alloca (wbuffer_to_alloc);
- wcp = wstartp = wbuffer + 2; /* Let room for rounding. */
+ wcp = wstartp = wscbuf.data + 2; /* Let room for rounding. */
/* Do the real work: put digits in allocated buffer. */
if (p->expsign == 0 || p->type != 'f')
@@ -951,10 +936,9 @@ __printf_fp_buffer_2 (struct hack_digit_param *p, struct __printf_buffer *buf,
if (info->left)
__printf_buffer_pad (buf, info->pad, width);
- }
- if (buffer_malloced)
- free (wbuffer);
+ scratch_buffer_free (&wscbuf);
+ }
}
#define PRINTF_FP_FETCH(P, FLOAT, SUFFIX, MANT_DIG) \
--
2.34.1
next prev parent reply other threads:[~2023-09-14 14:06 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-14 14:06 [PATCH v2 0/2] Remove print_fp " Adhemerval Zanella
2023-09-14 14:06 ` [PATCH v2 1/2] stdio: Remove __printf_fp_buffer_1 " Adhemerval Zanella
2023-09-14 14:06 ` Adhemerval Zanella [this message]
-- strict thread matches above, loose matches on Subject: below --
2023-09-11 13:50 [PATCH v2 0/2] Remove print_fp " Adhemerval Zanella
2023-09-11 13:50 ` [PATCH v2 2/2] stdio: Remove __printf_fp_buffer_2 " Adhemerval Zanella
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