[PATCH] fix flonum hashing regression from r45384

[Eric Wong <e@80x24.org>]

* st.c (st_numhash): use float value for flonum
* hash.c (rb_any_hash): ditto
* benchmark/bm_hash_aref_flo.rb: new benchmark
* benchmark/bm_hash_aref_flo_ident.rb: ditto
  [Bug #10761]
---
 benchmark/bm_hash_aref_flo.rb       | 4 ++++
 benchmark/bm_hash_aref_flo_ident.rb | 4 ++++
 hash.c                              | 7 ++++++-
 st.c                                | 5 +++++
 4 files changed, 19 insertions(+), 1 deletion(-)
 create mode 100644 benchmark/bm_hash_aref_flo.rb
 create mode 100644 benchmark/bm_hash_aref_flo_ident.rb

diff --git a/benchmark/bm_hash_aref_flo.rb b/benchmark/bm_hash_aref_flo.rb
new file mode 100644
index 0000000..a097bb5
--- /dev/null
+++ b/benchmark/bm_hash_aref_flo.rb
@@ -0,0 +1,4 @@
+h = {}
+strs = (1..10000).to_a.map!(&:to_f)
+strs.each { |s| h[s] = s }
+50.times { strs.each { |s| h[s] } }
diff --git a/benchmark/bm_hash_aref_flo_ident.rb b/benchmark/bm_hash_aref_flo_ident.rb
new file mode 100644
index 0000000..0c7edfe
--- /dev/null
+++ b/benchmark/bm_hash_aref_flo_ident.rb
@@ -0,0 +1,4 @@
+h = {}.compare_by_identity
+strs = (1..10000).to_a.map!(&:to_f)
+strs.each { |s| h[s] = s }
+50.times { strs.each { |s| h[s] } }
diff --git a/hash.c b/hash.c
index d54ab8a..3a90fdb 100644
--- a/hash.c
+++ b/hash.c
@@ -137,7 +137,12 @@ rb_any_hash(VALUE a)
 
     if (SPECIAL_CONST_P(a)) {
 	if (a == Qundef) return 0;
-	if (STATIC_SYM_P(a)) a >>= (RUBY_SPECIAL_SHIFT + ID_SCOPE_SHIFT);
+	if (STATIC_SYM_P(a)) {
+	    a >>= (RUBY_SPECIAL_SHIFT + ID_SCOPE_SHIFT);
+	}
+	else if (FLONUM_P(a)) {
+	    a = (st_index_t)rb_float_value(a);
+	}
 	hnum = rb_objid_hash((st_index_t)a);
     }
     else if (BUILTIN_TYPE(a) == T_STRING) {
diff --git a/st.c b/st.c
index b7f66d0..2ffa986 100644
--- a/st.c
+++ b/st.c
@@ -1762,5 +1762,10 @@ st_numhash(st_data_t n)
      * - avoid expensive modulo instructions, it is currently only
      *   shifts and bitmask operations.
      */
+#ifdef USE_FLONUM /* RUBY */
+    if (FLONUM_P(n))
+	return (st_index_t)rb_float_value(n);
+#endif
+
     return (st_index_t)((n>>(RUBY_SPECIAL_SHIFT+3)|(n<<3)) ^ (n>>3));
 }
-- 
EW