From 2afc1e0b30efd4b6460a42e692314a82832676bd Mon Sep 17 00:00:00 2001
From: Ian Lance Taylor <ian@gcc.gnu.org>
Date: Sat, 22 Sep 2012 06:06:31 +0000
Subject: [PATCH] runtime: Return random number of hash of NaN.

From-SVN: r191632
---
 libgo/runtime/go-type-complex.c | 14 ++++++++++----
 libgo/runtime/go-type-float.c   | 14 ++++++++++++--
 2 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/libgo/runtime/go-type-complex.c b/libgo/runtime/go-type-complex.c
index f923c867d995..106024f5c88b 100644
--- a/libgo/runtime/go-type-complex.c
+++ b/libgo/runtime/go-type-complex.c
@@ -32,10 +32,14 @@ __go_type_hash_complex (const void *vkey, uintptr_t key_size)
       cf = ucf.cf;
       cfr = __builtin_crealf (cf);
       cfi = __builtin_cimagf (cf);
-      if (__builtin_isinff (cfr) || __builtin_isinff (cfi)
-	  || __builtin_isnanf (cfr) || __builtin_isnanf (cfi))
+      if (__builtin_isinff (cfr) || __builtin_isinff (cfi))
 	return 0;
 
+      /* NaN != NaN, so the hash code of a NaN is irrelevant.  Make it
+	 random so that not all NaNs wind up in the same place.  */
+      if (__builtin_isnanf (cfr) || __builtin_isnanf (cfi))
+	return runtime_fastrand1 ();
+
       /* Avoid negative zero.  */
       if (cfr == 0 && cfi == 0)
 	return 0;
@@ -62,10 +66,12 @@ __go_type_hash_complex (const void *vkey, uintptr_t key_size)
       cd = ucd.cd;
       cdr = __builtin_crealf (cd);
       cdi = __builtin_cimagf (cd);
-      if (__builtin_isinf (cdr) || __builtin_isinf (cdi)
-	  || __builtin_isnan (cdr) || __builtin_isnan (cdi))
+      if (__builtin_isinf (cdr) || __builtin_isinf (cdi))
 	return 0;
 
+      if (__builtin_isnan (cdr) || __builtin_isnan (cdi))
+	return runtime_fastrand1 ();
+
       /* Avoid negative zero.  */
       if (cdr == 0 && cdi == 0)
 	return 0;
diff --git a/libgo/runtime/go-type-float.c b/libgo/runtime/go-type-float.c
index cc6e247e531c..e1c03e428439 100644
--- a/libgo/runtime/go-type-float.c
+++ b/libgo/runtime/go-type-float.c
@@ -29,8 +29,14 @@ __go_type_hash_float (const void *vkey, uintptr_t key_size)
 
       __builtin_memcpy (uf.a, vkey, 4);
       f = uf.f;
-      if (__builtin_isinff (f) || __builtin_isnanf (f) || f == 0)
+      if (__builtin_isinff (f) || f == 0)
 	return 0;
+
+      /* NaN != NaN, so the hash code of a NaN is irrelevant.  Make it
+	 random so that not all NaNs wind up in the same place.  */
+      if (__builtin_isnanf (f))
+	return runtime_fastrand1 ();
+
       return (uintptr_t) uf.si;
     }
   else if (key_size == 8)
@@ -45,8 +51,12 @@ __go_type_hash_float (const void *vkey, uintptr_t key_size)
 
       __builtin_memcpy (ud.a, vkey, 8);
       d = ud.d;
-      if (__builtin_isinf (d) || __builtin_isnan (d) || d == 0)
+      if (__builtin_isinf (d) || d == 0)
 	return 0;
+
+      if (__builtin_isnan (d))
+	return runtime_fastrand1 ();
+
       return (uintptr_t) ud.di;
     }
   else