Optimise if (%foo) to be faster than if(keys %foo)

Thread was "[PATCH] Make if (%hash) {} act the same as if (keys %hash) {}"
http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2006-11/msg00432.html
but the implementation evolved from the approach described in the subject, to
instead add a new opcode pp_boolkeys, to exactly preserve the existing
behaviour.

Various conflicts with the passage of time resolved, 'register' removed, and a
$VERSION bump.

1 files changed, 7 insertions, 0 deletions

diff --git a/proto.h b/proto.h
index db9093db4b..186bf40fbe 100644
--- a/proto.h
+++ b/proto.h
@@ -1400,6 +1400,13 @@ PERL_CALLCONV I32	Perl_keyword(pTHX_ const char *name, I32 len, bool all_keyword
 #define PERL_ARGS_ASSERT_KEYWORD	\
 	assert(name)
 
+#if defined(PERL_IN_OP_C) || defined(PERL_DECL_PROT)
+STATIC OP*	S_opt_scalarhv(pTHX_ OP* rep_op)
+			__attribute__nonnull__(pTHX_1);
+#define PERL_ARGS_ASSERT_OPT_SCALARHV	\
+	assert(rep_op)
+
+#endif
 PERL_CALLCONV void	Perl_leave_scope(pTHX_ I32 base);
 PERL_CALLCONV void	Perl_lex_end(pTHX);
 PERL_CALLCONV void	Perl_lex_start(pTHX_ SV* line, PerlIO *rsfp, bool new_filter);