From: Jason Merrill <jason@redhat.com>
Date: Fri, 20 Mar 2009 21:49:18 +0000 (-0400)
Subject: C++ core issue 703
X-Git-Tag: releases/gcc-4.4.0~215
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=7225892923ccd028607f1755ba7e30ae553d33df;p=thirdparty%2Fgcc.git

C++ core issue 703

        C++ core issue 703
        * typeck2.c (check_narrowing): Don't complain about loss of
        precision when converting a floating-point constant.

From-SVN: r144979
---

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index f53394424bfe..a4eb86a8b6b1 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,9 @@
+2009-03-20  Jason Merrill  <jason@redhat.com>
+
+	C++ core issue 703
+	* typeck2.c (check_narrowing): Don't complain about loss of 
+	precision when converting a floating-point constant.
+
 2009-03-19  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c/39495
diff --git a/gcc/cp/typeck2.c b/gcc/cp/typeck2.c
index 637076554fb8..747c964706cd 100644
--- a/gcc/cp/typeck2.c
+++ b/gcc/cp/typeck2.c
@@ -677,18 +677,18 @@ check_narrowing (tree type, tree init)
     {
       if (TYPE_PRECISION (type) < TYPE_PRECISION (ftype))
 	{
-	  ok = false;
 	  if (TREE_CODE (init) == REAL_CST)
 	    {
+	      /* Issue 703: Loss of precision is OK as long as the value is
+		 within the representable range of the new type.  */
+	      REAL_VALUE_TYPE r;
 	      d = TREE_REAL_CST (init);
-	      if (exact_real_truncate (TYPE_MODE (type), &d)
-		  /* FIXME: As a temporary workaround for PR 36963, don't
-		     complain about narrowing from a floating
-		     literal. Hopefully this will be resolved at the
-		     September 2008 C++ meeting. */
-		  || !was_decl)
-		ok = true;
+	      real_convert (&r, TYPE_MODE (type), &d);
+	      if (real_isinf (&r))
+		ok = false;
 	    }
+	  else
+	    ok = false;
 	}
     }
   else if (INTEGRAL_OR_ENUMERATION_TYPE_P (ftype)
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index c7c1e583fbb8..16d50f4cee0b 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2009-03-20  Jason Merrill  <jason@redhat.com>
+
+	* g++.dg/cpp0x/initlist5.C: Add additional test.
+
 2009-03-19  Jakub Jelinek  <jakub@redhat.com>
 	    Janis Johnson  <janis187@us.ibm.com>
 
diff --git a/gcc/testsuite/g++.dg/cpp0x/initlist5.C b/gcc/testsuite/g++.dg/cpp0x/initlist5.C
index fbdc673948f1..958007c9bd85 100644
--- a/gcc/testsuite/g++.dg/cpp0x/initlist5.C
+++ b/gcc/testsuite/g++.dg/cpp0x/initlist5.C
@@ -20,6 +20,8 @@ C c2 = { 1.1, 2 }; // { dg-error "narrowing" }
 int j { 1 }; // initialize to 1
 int k {}; // initialize to 0
 
-// PR c++/39693
+// PR c++/36963
 double d = 1.1;
 float fa[] = { d, 1.1 };      // { dg-error "narrowing conversion of 'd'" }
+const double d2 = 1.1;
+float fa2[] = { d2, 1.1 };