Avoid pointer churn in study_chunk recursion bitmap allocation

Since we can only recurse into a given paren (or the entire pattern)
once, we know that the maximum recursion depth is the number of parens
in the pattern (plus one for "whole pattern"). This means we can
preallocate one large bitmap, and then use different chunks of it
for each level. That avoids SAVEFREEPV costs for each bitmap, which
are likely short anyway. (One could imagine an optimization where a
flag somewhere lets us use the RExC_study_chunk_recursed pointer
as a bitmap, so we dont have to allocate all when we have less than
32 parens.)

This removes the "recursed" argument from study_chunk() and replaces
it with a "recursive_depth" argument which counts how deep we
are in the bitmap "stack".

1 files changed, 1 insertions, 1 deletions

diff --git a/proto.h b/proto.h
index da3bbb958f..49b586d2dd 100644
--- a/proto.h
+++ b/proto.h
@@ -6902,7 +6902,7 @@ PERL_STATIC_INLINE void	S_ssc_union(pTHX_ regnode_ssc *ssc, SV* const invlist, c
 #define PERL_ARGS_ASSERT_SSC_UNION	\
 	assert(ssc); assert(invlist)
 
-STATIC SSize_t	S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp, SSize_t *minlenp, SSize_t *deltap, regnode *last, struct scan_data_t *data, I32 stopparen, U8* recursed, regnode_ssc *and_withp, U32 flags, U32 depth)
+STATIC SSize_t	S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp, SSize_t *minlenp, SSize_t *deltap, regnode *last, struct scan_data_t *data, I32 stopparen, U32 recursed_depth, regnode_ssc *and_withp, U32 flags, U32 depth)
 			__attribute__nonnull__(pTHX_1)
 			__attribute__nonnull__(pTHX_2)
 			__attribute__nonnull__(pTHX_3)