convert.c (strip_float_extensions): Look for narrowest type handling FP constants.

	* convert.c (strip_float_extensions):  Look for narrowest type handling
	FP constants.

	* fold-const.c (fold):  Fold (double)float1 CMP (double)float2 into
	float1 CMP float2.
	* convert.c (strip_float_extensions): Make global.
	* tree.h (strip_float_extensions): Declare.

	* gcc.dg/i386-fpcvt-1.c: New test.
	* gcc.dg/i386-fpcvt-2.c: New test.

From-SVN: r61279

gcc/ChangeLog

+Tue Jan 14 00:45:33 CET 2003  Jan Hubicka  <jh@suse.cz>
+
+	* convert.c (strip_float_extensions):  Look for narrowest type handling
+	FP constants.
+
+	* fold-const.c (fold):  Fold (double)float1 CMP (double)float2 into
+	float1 CMP float2.
+	* convert.c (strip_float_extensions): Make global.
+	* tree.h (strip_float_extensions): Declare.
+
 2003-01-14  Gabriel Dos Reis  <gdr@integrable-solutions.net>
 
 	* timevar.def: define TV_NAME_LOOKUP.

gcc/Makefile.in

@@ -1215,7 +1215,7 @@ c-objc-common.o : c-objc-common.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) $(
 c-aux-info.o : c-aux-info.c  $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) $(TREE_H) \
     $(C_TREE_H) flags.h toplev.h
 c-convert.o : c-convert.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) $(TREE_H) \
-    flags.h toplev.h $(C_COMMON_H)
+    flags.h toplev.h $(C_COMMON_H) real.h
 c-pragma.o: c-pragma.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) $(RTL_H) $(TREE_H) \
     function.h c-pragma.h toplev.h output.h $(GGC_H) $(TM_P_H) $(C_COMMON_H) gt-c-pragma.h
 mbchar.o: mbchar.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) mbchar.h

gcc/convert.c

@@ -32,8 +32,7 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 #include "convert.h"
 #include "toplev.h"
 #include "langhooks.h"
-static tree strip_float_extensions PARAMS ((tree));
-
+#include "real.h"
 /* Convert EXPR to some pointer or reference type TYPE.
 
    EXPR must be pointer, reference, integer, enumeral, or literal zero;
@@ -75,12 +74,33 @@ convert_to_pointer (type, expr)
 }
 
 /* Avoid any floating point extensions from EXP.  */
-static tree
+tree
 strip_float_extensions (exp)
      tree exp;
 {
   tree sub, expt, subt;
 
+  /*  For floating point constant look up the narrowest type that can hold
+      it properly and handle it like (type)(narrowest_type)constant.
+      This way we can optimize for instance a=a*2.0 where "a" is float
+      but 2.0 is double constant.  */
+  if (TREE_CODE (exp) == REAL_CST)
+    {
+      REAL_VALUE_TYPE orig;
+      tree type = NULL;
+
+      orig = TREE_REAL_CST (exp);
+      if (TYPE_PRECISION (TREE_TYPE (exp)) > TYPE_PRECISION (float_type_node)
+	  && exact_real_truncate (TYPE_MODE (float_type_node), &orig))
+	type = float_type_node;
+      else if (TYPE_PRECISION (TREE_TYPE (exp))
+	       > TYPE_PRECISION (double_type_node)
+	       && exact_real_truncate (TYPE_MODE (double_type_node), &orig))
+	type = double_type_node;
+      if (type)
+	return build_real (type, real_value_truncate (TYPE_MODE (type), orig));
+    }
+
   if (TREE_CODE (exp) != NOP_EXPR)
     return exp;
 

gcc/fold-const.c

@@ -6041,6 +6041,18 @@ fold (expr)
 
       if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
 	{
+	  tree targ0 = strip_float_extensions (arg0);
+	  tree targ1 = strip_float_extensions (arg1);
+	  tree newtype = TREE_TYPE (targ0);
+
+	  if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
+	    newtype = TREE_TYPE (targ1);
+
+	  /* Fold (double)float1 CMP (double)float2 into float1 CMP float2.  */
+	  if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
+	    return fold (build (code, type, convert (newtype, targ0),
+				convert (newtype, targ1)));
+
 	  /* (-a) CMP (-b) -> b CMP a  */
 	  if (TREE_CODE (arg0) == NEGATE_EXPR
 	      && TREE_CODE (arg1) == NEGATE_EXPR)

gcc/testsuite/ChangeLog

+Tue Jan 14 00:45:03 CET 2003  Jan Hubicka  <jh@suse.cz>
+
+	* gcc.dg/i386-fpcvt-1.c: New test.
+	* gcc.dg/i386-fpcvt-2.c: New test.
+
 2003-01-14  Eric Botcazou  <ebotcazou@libertysurf.fr>
 
 	* gcc.dg/i386-mmx-3.c: New test.

gcc/testsuite/gcc.dg/i386-fpcvt-1.c

+/* { dg-do compile { target i?86-*-* x86_64-*-* } } */
+/* { dg-options "-O2 -msse2 -march=athlon" } */
+/* { dg-final { scan-assembler-not "cvtss2sd" } } */
+float a,b;
+main()
+{
+  a=b*3.0;
+}

gcc/testsuite/gcc.dg/i386-fpcvt-2.c

+/* { dg-do compile { target i?86-*-* x86_64-*-* } } */
+/* { dg-options "-O2 -msse2 -march=athlon" } */
+/* { dg-final { scan-assembler-not "cvtss2sd" } } */
+float a,b;
+main()
+{
+	return a<0.0;
+}

gcc/tree.h

@@ -2929,6 +2929,9 @@ extern tree fold_builtin				PARAMS ((tree));
 extern enum built_in_function builtin_mathfn_code	PARAMS ((tree));
 extern tree build_function_call_expr			PARAMS ((tree, tree));
 
+/* In convert.c */
+extern tree strip_float_extensions			PARAMS ((tree));
+
 /* In alias.c */
 extern void record_component_aliases		PARAMS ((tree));
 extern HOST_WIDE_INT get_alias_set		PARAMS ((tree));