https://gcc.gnu.org/g:b2c1d7c4573d3b938f44b3bda202adeb292b1cbc
commit r15-3121-gb2c1d7c4573d3b938f44b3bda202adeb292b1cbc
Author: Alexander Monakov <amona...@ispras.ru>
Date: Thu Aug 22 21:09:47 2024 +0300
libcpp: bump padding size in _cpp_convert_input [PR116458]
The recently introduced search_line_fast_ssse3 raised padding
requirement from 16 to 64, which was adjusted in read_file_guts,
but the corresponding ' + 16' in _cpp_convert_input was overlooked.
libcpp/ChangeLog:
PR preprocessor/116458
* charset.cc (_cpp_convert_input): Bump padding to 64 if
HAVE_SSSE3.
Diff:
---
libcpp/charset.cc | 21 ++++++++++++---------
1 file changed, 12 insertions(+), 9 deletions(-)
diff --git a/libcpp/charset.cc b/libcpp/charset.cc
index d58319a500a1..79072877cbf7 100644
--- a/libcpp/charset.cc
+++ b/libcpp/charset.cc
@@ -3093,6 +3093,7 @@ _cpp_convert_input (cpp_reader *pfile, const char
*input_charset,
struct cset_converter input_cset;
struct _cpp_strbuf to;
unsigned char *buffer;
+ size_t pad;
input_cset = init_iconv_desc (pfile, SOURCE_CHARSET, input_charset);
if (input_cset.func == convert_no_conversion)
@@ -3129,16 +3130,18 @@ _cpp_convert_input (cpp_reader *pfile, const char
*input_charset,
}
}
+#ifdef HAVE_SSSE3
+ pad = 64;
+#else
+ pad = 16;
+#endif
/* Resize buffer if we allocated substantially too much, or if we
- haven't enough space for the \n-terminator or following
- 15 bytes of padding (used to quiet warnings from valgrind or
- Address Sanitizer, when the optimized lexer accesses aligned
- 16-byte memory chunks, including the bytes after the malloced,
- area, and stops lexing on '\n'). */
- if (to.len + 4096 < to.asize || to.len + 16 > to.asize)
- to.text = XRESIZEVEC (uchar, to.text, to.len + 16);
-
- memset (to.text + to.len, '\0', 16);
+ don't have enough space for the following padding, which allows
+ search_line_fast to use (possibly misaligned) vector loads. */
+ if (to.len + 4096 < to.asize || to.len + pad > to.asize)
+ to.text = XRESIZEVEC (uchar, to.text, to.len + pad);
+
+ memset (to.text + to.len, '\0', pad);
/* If the file is using old-school Mac line endings (\r only),
terminate with another \r, not an \n, so that we do not mistake
