Andy suggested this. Okay to push to stable-2.0?
Mark
>From 0b70eba61ee26654f442199e7cc49838c5b0030e Mon Sep 17 00:00:00 2001
From: Mark H Weaver <m...@netris.org>
Date: Tue, 2 Apr 2013 05:33:24 -0400
Subject: [PATCH] Move slow path out of 'scm_get_byte_or_eof' et al.
Suggested by Andy Wingo.
* libguile/inline.h (scm_get_byte_or_eof, scm_peek_byte_or_eof): Keep
only the fast path here, with fallback to 'scm_i_get_byte_or_eof' and
'scm_i_peek_byte_or_eof'.
* libguile/ports.c (scm_i_get_byte_or_eof, scm_i_peek_byte_or_eof): New
internal functions.
* libguile/ports.h (scm_i_get_byte_or_eof, scm_i_peek_byte_or_eof): Add
prototypes.
---
libguile/inline.h | 44 ++++++++++----------------------------------
libguile/ports.c | 41 +++++++++++++++++++++++++++++++++++++++++
libguile/ports.h | 2 ++
3 files changed, 53 insertions(+), 34 deletions(-)
diff --git a/libguile/inline.h b/libguile/inline.h
index 88ba7f7..17d8a0c 100644
--- a/libguile/inline.h
+++ b/libguile/inline.h
@@ -96,50 +96,26 @@ scm_is_string (SCM x)
SCM_INLINE_IMPLEMENTATION int
scm_get_byte_or_eof (SCM port)
{
- int c;
scm_t_port *pt = SCM_PTAB_ENTRY (port);
- if (pt->rw_active == SCM_PORT_WRITE)
- /* may be marginally faster than calling scm_flush. */
- scm_ptobs[SCM_PTOBNUM (port)].flush (port);
-
- if (pt->rw_random)
- pt->rw_active = SCM_PORT_READ;
-
- if (pt->read_pos >= pt->read_end)
- {
- if (SCM_UNLIKELY (scm_fill_input (port) == EOF))
- return EOF;
- }
-
- c = *(pt->read_pos++);
-
- return c;
+ if (SCM_LIKELY ((pt->rw_active == SCM_PORT_READ || !pt->rw_random)
+ && pt->read_pos < pt->read_end))
+ return *pt->read_pos++;
+ else
+ return scm_i_get_byte_or_eof (port);
}
/* Like `scm_get_byte_or_eof' but does not change PORT's `read_pos'. */
SCM_INLINE_IMPLEMENTATION int
scm_peek_byte_or_eof (SCM port)
{
- int c;
scm_t_port *pt = SCM_PTAB_ENTRY (port);
- if (pt->rw_active == SCM_PORT_WRITE)
- /* may be marginally faster than calling scm_flush. */
- scm_ptobs[SCM_PTOBNUM (port)].flush (port);
-
- if (pt->rw_random)
- pt->rw_active = SCM_PORT_READ;
-
- if (pt->read_pos >= pt->read_end)
- {
- if (SCM_UNLIKELY (scm_fill_input (port) == EOF))
- return EOF;
- }
-
- c = *pt->read_pos;
-
- return c;
+ if (SCM_LIKELY ((pt->rw_active == SCM_PORT_READ || !pt->rw_random)
+ && pt->read_pos < pt->read_end))
+ return *pt->read_pos;
+ else
+ return scm_i_peek_byte_or_eof (port);
}
SCM_INLINE_IMPLEMENTATION void
diff --git a/libguile/ports.c b/libguile/ports.c
index becdbed..76ec83f 100644
--- a/libguile/ports.c
+++ b/libguile/ports.c
@@ -1439,6 +1439,47 @@ scm_fill_input (SCM port)
return scm_ptobs[SCM_PTOBNUM (port)].fill_input (port);
}
+/* Slow-path fallback for 'scm_get_byte_or_eof' in inline.h */
+int
+scm_i_get_byte_or_eof (SCM port)
+{
+ scm_t_port *pt = SCM_PTAB_ENTRY (port);
+
+ if (pt->rw_active == SCM_PORT_WRITE)
+ scm_flush (port);
+
+ if (pt->rw_random)
+ pt->rw_active = SCM_PORT_READ;
+
+ if (pt->read_pos >= pt->read_end)
+ {
+ if (SCM_UNLIKELY (scm_fill_input (port) == EOF))
+ return EOF;
+ }
+
+ return *pt->read_pos++;
+}
+
+/* Slow-path fallback for 'scm_peek_byte_or_eof' in inline.h */
+int
+scm_i_peek_byte_or_eof (SCM port)
+{
+ scm_t_port *pt = SCM_PTAB_ENTRY (port);
+
+ if (pt->rw_active == SCM_PORT_WRITE)
+ scm_flush (port);
+
+ if (pt->rw_random)
+ pt->rw_active = SCM_PORT_READ;
+
+ if (pt->read_pos >= pt->read_end)
+ {
+ if (SCM_UNLIKELY (scm_fill_input (port) == EOF))
+ return EOF;
+ }
+
+ return *pt->read_pos;
+}
/* scm_lfwrite
*
diff --git a/libguile/ports.h b/libguile/ports.h
index 53d5081..54bf595 100644
--- a/libguile/ports.h
+++ b/libguile/ports.h
@@ -328,6 +328,8 @@ scm_i_default_port_conversion_handler (void);
/* Use HANDLER as the default conversion strategy for future ports. */
SCM_INTERNAL void
scm_i_set_default_port_conversion_handler (scm_t_string_failed_conversion_handler);
+SCM_INTERNAL int scm_i_get_byte_or_eof (SCM port);
+SCM_INTERNAL int scm_i_peek_byte_or_eof (SCM port);
SCM_API SCM scm_port_conversion_strategy (SCM port);
SCM_API SCM scm_set_port_conversion_strategy_x (SCM port, SCM behavior);
--
1.7.10.4
