From 06c6da524f9e0eae167367edc8fe0150d69893fa Mon Sep 17 00:00:00 2001 From: David Mitchell Date: Tue, 21 Jun 2011 17:32:20 +0100 Subject: pp_ncmp: favour the non- Perl_isnan route Currently pp_ncmp(), when comparing two NVs, prefers to check its two args for NaNness first, and if either of them are, then return undef. Only if Perl_isnan isn't defined does it fall back to doing three compares (<, >, =) where if all three fail it returns undef. This is in contrast to the other compare functions (e.g. pp_lt), which only use Perl_isnan if NAN_COMPARE_BROKEN is defined - i.e. they prefer to rely on the '<' (or whatever) test to handle NaNs implicitly. Change pp_ncmp to favour not using Perl_isnan(). This has two advantages: First, speed: in the normal case we replace: two function calls to Perl_isnan plus two comparisons, with: three comparisons. Second, this makes pp_ncmp more similar to the other comparison functions, allowing for code reuse in the future. --- pp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/pp.c b/pp.c index 2cbbfddbdc..997b5ba783 100644 --- a/pp.c +++ b/pp.c @@ -2439,7 +2439,7 @@ PP(pp_ncmp) dPOPTOPnnrl_nomg; I32 value; -#ifdef Perl_isnan +#if defined(NAN_COMPARE_BROKEN) && defined(Perl_isnan) if (Perl_isnan(left) || Perl_isnan(right)) { SETs(&PL_sv_undef); RETURN; -- cgit v1.2.1