https://gcc.gnu.org/g:e2f024f586e99fb63dd49e0603f52d1cb765a77e
commit r15-7211-ge2f024f586e99fb63dd49e0603f52d1cb765a77e
Author: Andi Kleen <a...@gcc.gnu.org>
Date: Wed Dec 25 20:21:58 2024 -0800
Move ferror out of hot loop of file cache
glibc ferror is surprisingly expensive. Move it out of the hot loop
of finding lines by setting a flag after the actual IO operations.
gcc/ChangeLog:
PR preprocessor/118168
* input.cc (file_cache_slot::m_error): New field.
(file_cache_slot::create): Clear m_error.
(file_cache_slot::file_cache_slot): Clear m_error.
(file_cache_slot::read_data): Set m_error on error.
(file_cache_slot::get_next_line): Use m_error instead of ferror.
Diff:
---
gcc/input.cc | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)
diff --git a/gcc/input.cc b/gcc/input.cc
index 7ed80cad13f4..a2953ed1b156 100644
--- a/gcc/input.cc
+++ b/gcc/input.cc
@@ -131,6 +131,9 @@ public:
FILE *m_fp;
+ /* True when an read error happened. */
+ bool m_error;
+
/* This points to the content of the file that we've read so
far. */
char *m_data;
@@ -396,6 +399,7 @@ file_cache_slot::evict ()
m_file_path = NULL;
if (m_fp)
fclose (m_fp);
+ m_error = false;
m_fp = NULL;
m_nb_read = 0;
m_line_start_idx = 0;
@@ -491,6 +495,7 @@ file_cache_slot::create (const file_cache::input_context
&in_context,
m_file_path = file_path;
if (m_fp)
fclose (m_fp);
+ m_error = false;
m_fp = fp;
if (m_alloc_offset)
offset_buffer (-m_alloc_offset);
@@ -613,7 +618,7 @@ file_cache::lookup_or_add_file (const char *file_path)
diagnostic. */
file_cache_slot::file_cache_slot ()
-: m_use_count (0), m_file_path (NULL), m_fp (NULL), m_data (0),
+: m_use_count (0), m_file_path (NULL), m_fp (NULL), m_error (false), m_data
(0),
m_alloc_offset (0), m_size (0), m_nb_read (0), m_line_start_idx (0),
m_line_num (0), m_total_lines (0), m_missing_trailing_newline (true)
{
@@ -728,7 +733,10 @@ file_cache_slot::read_data ()
size_t nb_read = fread (from, 1, to_read, m_fp);
if (ferror (m_fp))
- return false;
+ {
+ m_error = true;
+ return false;
+ }
m_nb_read += nb_read;
return !!nb_read;
@@ -846,7 +854,7 @@ file_cache_slot::get_next_line (char **line, ssize_t
*line_len)
m_missing_trailing_newline = false;
}
- if (m_fp && ferror (m_fp))
+ if (m_error)
return false;
/* At this point, we've found the end of the of line. It either points to
