optimize FIXABLE macro

Looking at the source code, FIXABLE tends to be just before LOING2FIX
to check applicability of that operation.  Why not try computing first
then check for overflow, which should be optimial.

I also tried the same thing for unsigned types but resulted in slower
execution.  It seems RB_POSFIXABLE() is fast enough on modern CPUs.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57789 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 1 insertions, 1 deletions

diff --git a/insns.def b/insns.def
index 9bae14b5a9..15e9d828ea 100644
--- a/insns.def
+++ b/insns.def
@@ -1345,7 +1345,7 @@ opt_case_dispatch
 	    if (RB_FLOAT_TYPE_P(key)) {
 		double kval = RFLOAT_VALUE(key);
 		if (!isinf(kval) && modf(kval, &kval) == 0.0) {
-		    key = FIXABLE(kval) ? LONG2FIX((long)kval) : rb_dbl2big(kval);
+		    key = rb_dbl2ival(kval);
 		}
 	    }
 	    if (st_lookup(RHASH_TBL_RAW(hash), key, &val)) {