Upstream-Status: Inappropriate [Backport]
From b6ed53c51ca6090f3f422e6223e8dc3b150f0393 Mon Sep 17 00:00:00 2001
From: jakub <jakub@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Sat, 26 Mar 2011 09:24:06 +0000
Subject: [PATCH 006/200] 	Backport from mainline
 	2011-03-24  Jakub Jelinek  <jakub@redhat.com>

	PR debug/48204
	* simplify-rtx.c (simplify_const_unary_operation): Call
	real_convert when changing mode class with FLOAT_EXTEND.

	* gcc.dg/dfp/pr48204.c: New test.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/gcc-4_6-branch@171549 138bc75d-0d04-0410-961f-82ee72b054a4

index ce4eab4..ed6ae2b 100644
--- a/gcc/simplify-rtx.c
+++ b/gcc/simplify-rtx.c
@@ -1526,7 +1526,8 @@ simplify_const_unary_operation (enum rtx_code code, enum machine_mode mode,
     }
 
   else if (GET_CODE (op) == CONST_DOUBLE
-	   && SCALAR_FLOAT_MODE_P (mode))
+	   && SCALAR_FLOAT_MODE_P (mode)
+	   && SCALAR_FLOAT_MODE_P (GET_MODE (op)))
     {
       REAL_VALUE_TYPE d, t;
       REAL_VALUE_FROM_CONST_DOUBLE (d, op);
@@ -1549,7 +1550,10 @@ simplify_const_unary_operation (enum rtx_code code, enum machine_mode mode,
 	  d = real_value_truncate (mode, d);
 	  break;
 	case FLOAT_EXTEND:
-	  /* All this does is change the mode.  */
+	  /* All this does is change the mode, unless changing
+	     mode class.  */
+	  if (GET_MODE_CLASS (mode) != GET_MODE_CLASS (GET_MODE (op)))
+	    real_convert (&d, mode, &d);
 	  break;
 	case FIX:
 	  real_arithmetic (&d, FIX_TRUNC_EXPR, &d, NULL);
new file mode 100644
index 0000000..7b42158
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/dfp/pr48204.c
@@ -0,0 +1,10 @@
+/* PR debug/48204 */
+/* { dg-do compile } */
+/* { dg-options "-O -fno-tree-ccp -fno-tree-dominator-opts -fno-tree-fre -g" } */
+
+void
+foo (void)
+{
+  float cf = 3.0f;
+  _Decimal64 d64 = cf;
+}
-- 
1.7.0.4