diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 80caad9edde..0ec948f9b2a 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2006-07-25  Roger Sayle  <roger@eyesopen.com>
+
+	PR middle-end/28473
+	* convert.c (convert_to_integer): When transforming (T)foo(x) into
+	bar(x) check that bar's result type can represent all the values of T.
+
 2006-07-25  Zdenek Dvorak <dvorakz@suse.cz>
 
 	* tree-chrec.c (chrec_convert_aggressive): Return NULL on failure.
diff --git a/gcc/convert.c b/gcc/convert.c
index ab780d8ebd3..27571956a1e 100644
--- a/gcc/convert.c
+++ b/gcc/convert.c
@@ -388,27 +388,36 @@ convert_to_integer (tree type, tree expr)
 	  /* Only convert in ISO C99 mode.  */
 	  if (!TARGET_C99_FUNCTIONS)
 	    break;
-	  if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (long_long_integer_type_node))
-	    fn = mathfn_built_in (s_intype, BUILT_IN_LLCEIL);
-	  else
+	  if (outprec < TYPE_PRECISION (long_integer_type_node)
+	      || (outprec == TYPE_PRECISION (long_integer_type_node)
+		  && !TYPE_UNSIGNED (type)))
 	    fn = mathfn_built_in (s_intype, BUILT_IN_LCEIL);
+	  else if (outprec == TYPE_PRECISION (long_long_integer_type_node)
+		   && !TYPE_UNSIGNED (type))
+	    fn = mathfn_built_in (s_intype, BUILT_IN_LLCEIL);
 	  break;
 
 	CASE_FLT_FN (BUILT_IN_FLOOR):
 	  /* Only convert in ISO C99 mode.  */
 	  if (!TARGET_C99_FUNCTIONS)
 	    break;
-	  if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (long_long_integer_type_node))
-	    fn = mathfn_built_in (s_intype, BUILT_IN_LLFLOOR);
-	  else
+	  if (outprec < TYPE_PRECISION (long_integer_type_node)
+	      || (outprec == TYPE_PRECISION (long_integer_type_node)
+		  && !TYPE_UNSIGNED (type)))
 	    fn = mathfn_built_in (s_intype, BUILT_IN_LFLOOR);
+	  else if (outprec == TYPE_PRECISION (long_long_integer_type_node)
+		   && !TYPE_UNSIGNED (type))
+	    fn = mathfn_built_in (s_intype, BUILT_IN_LLFLOOR);
 	  break;
 
 	CASE_FLT_FN (BUILT_IN_ROUND):
-	  if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (long_long_integer_type_node))
-	    fn = mathfn_built_in (s_intype, BUILT_IN_LLROUND);
-	  else
+	  if (outprec < TYPE_PRECISION (long_integer_type_node)
+	      || (outprec == TYPE_PRECISION (long_integer_type_node)
+		  && !TYPE_UNSIGNED (type)))
 	    fn = mathfn_built_in (s_intype, BUILT_IN_LROUND);
+	  else if (outprec == TYPE_PRECISION (long_long_integer_type_node)
+		   && !TYPE_UNSIGNED (type))
+	    fn = mathfn_built_in (s_intype, BUILT_IN_LLROUND);
 	  break;
 
 	CASE_FLT_FN (BUILT_IN_RINT):
@@ -417,10 +426,13 @@ convert_to_integer (tree type, tree expr)
 	    break;
 	  /* ... Fall through ...  */
 	CASE_FLT_FN (BUILT_IN_NEARBYINT):
-	  if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (long_long_integer_type_node))
-            fn = mathfn_built_in (s_intype, BUILT_IN_LLRINT);
-	  else
-            fn = mathfn_built_in (s_intype, BUILT_IN_LRINT);
+	  if (outprec < TYPE_PRECISION (long_integer_type_node)
+	      || (outprec == TYPE_PRECISION (long_integer_type_node)
+		  && !TYPE_UNSIGNED (type)))
+	    fn = mathfn_built_in (s_intype, BUILT_IN_LRINT);
+	  else if (outprec == TYPE_PRECISION (long_long_integer_type_node)
+		   && !TYPE_UNSIGNED (type))
+	    fn = mathfn_built_in (s_intype, BUILT_IN_LLRINT);
 	  break;
 
 	CASE_FLT_FN (BUILT_IN_TRUNC):
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 00fd5b8e53b..63aadaf8e28 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2006-07-25  Roger Sayle  <roger@eyesopen.com>
+
+	PR middle-end/28473
+	* gcc.dg/fold-convround-1.c: New test case.
+
 2006-07-24  Steven G. Kargl  <kargls@comcast.net>
 
 	* gfortran.dg/arithmetic_if.f90:  Fix comments.
diff --git a/gcc/testsuite/gcc.dg/fold-convround-1.c b/gcc/testsuite/gcc.dg/fold-convround-1.c
new file mode 100644
index 00000000000..86612aa81b3
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/fold-convround-1.c
@@ -0,0 +1,30 @@
+/* PR middle-end/28473.  */
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-original" } */
+
+extern double round(double);
+extern double floor(double);
+extern double ceil(double);
+
+unsigned long long test1(double x)
+{
+  return (unsigned long long) round(x);
+}
+
+unsigned long long test2(double x)
+{
+  return (unsigned long long) floor(x);
+}
+unsigned long long test3(double x)
+{
+  return (unsigned long long) ceil(x);
+}
+
+/* { dg-final { scan-tree-dump-times "__builtin_lround" 0 "original" } } */
+/* { dg-final { scan-tree-dump-times "__builtin_llround" 0 "original" } } */
+/* { dg-final { scan-tree-dump-times "__builtin_lfloor" 0 "original" } } */
+/* { dg-final { scan-tree-dump-times "__builtin_llfloor" 0 "original" } } */
+/* { dg-final { scan-tree-dump-times "__builtin_lceil" 0 "original" } } */
+/* { dg-final { scan-tree-dump-times "__builtin_llceil" 0 "original" } } */
+/* { dg-final { cleanup-tree-dump "original" } } */
+