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authorSteffen Mueller <smueller@cpan.org>2013-03-06 20:39:43 +0100
committerSteffen Mueller <smueller@cpan.org>2013-03-06 20:39:43 +0100
commit2439e03355dec26654acf614900c077433bc27e0 (patch)
tree9bd0e7345aad6371d1f45065e869d791fb604c0c /pp.h
parent8da3792e39c8a8877091f33438f7191493dbefea (diff)
downloadperl-2439e03355dec26654acf614900c077433bc27e0.tar.gz
(UN)LIKELY branch prediction hints in a few strategic places
This adds branch prediction hints to a few strategic places such as growing stack or strings, some exception handling, and a few hot functions such as sv_upgrade. This is not exhaustive by any means.
Diffstat (limited to 'pp.h')
-rw-r--r--pp.h14
1 files changed, 7 insertions, 7 deletions
diff --git a/pp.h b/pp.h
index 377d489f26..cb6a0668f9 100644
--- a/pp.h
+++ b/pp.h
@@ -278,15 +278,15 @@ Does not use C<TARG>. See also C<XPUSHu>, C<mPUSHu> and C<PUSHu>.
=cut
*/
-#define EXTEND(p,n) (void)(PL_stack_max - p < (int)(n) && \
+#define EXTEND(p,n) (void)(UNLIKELY(PL_stack_max - p < (int)(n)) && \
(sp = stack_grow(sp,p, (int) (n))))
/* Same thing, but update mark register too. */
-#define MEXTEND(p,n) STMT_START {if (PL_stack_max - p < (int)(n)) { \
- const int markoff = mark - PL_stack_base; \
- sp = stack_grow(sp,p,(int) (n)); \
- mark = PL_stack_base + markoff; \
- } } STMT_END
+#define MEXTEND(p,n) STMT_START {if (UNLIKELY(PL_stack_max - p < (int)(n))) {\
+ const int markoff = mark - PL_stack_base; \
+ sp = stack_grow(sp,p,(int) (n)); \
+ mark = PL_stack_base + markoff; \
+ } } STMT_END
#define PUSHs(s) (*++sp = (s))
#define PUSHTARG STMT_START { SvSETMAGIC(TARG); PUSHs(TARG); } STMT_END
@@ -388,7 +388,7 @@ Does not use C<TARG>. See also C<XPUSHu>, C<mPUSHu> and C<PUSHu>.
#define EXTEND_MORTAL(n) \
STMT_START { \
- if (PL_tmps_ix + (n) >= PL_tmps_max) \
+ if (UNLIKELY(PL_tmps_ix + (n) >= PL_tmps_max)) \
tmps_grow(n); \
} STMT_END