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[Ada] Ensure consistency of fpt exponentiation results

Message ID 3550734.dbQtBZf86h@polaris
State New
Headers show

Commit Message

Eric Botcazou May 26, 2015, 8:19 p.m. UTC 
> This change ensures on all targets that A**B = A**C when B is a small
> static constant in the range 0 .. 4 and C is a variable with the same
> value. Previously for Float and Long_Float on some targets, this was
> not the case. The results given were both within the error bounds that
> are allowed by the Ada standard, but it is desirable not to have this
> discrepancy.

This uncovered a bug in gigi, responsible for 

                === acats tests ===
FAIL:  c44003d


Fixed thusly, tested on x86_64-suse-linux, applied on the mainline.


2015-05-26  Eric Botcazou  <ebotcazou@adacore.com>

	* gcc-interface/trans.c (Attribute_to_gnu) <Attr_Machine>: Do not apply
	extra-precision trick to literals.  Build SAVE_EXPR manually.
diff mbox

Patch

Index: gcc-interface/trans.c
===================================================================
--- gcc-interface/trans.c	(revision 223709)
+++ gcc-interface/trans.c	(working copy)
@@ -2428,7 +2428,8 @@  Attribute_to_gnu (Node_Id gnat_node, tre
       gnu_result_type = get_unpadded_type (Etype (gnat_node));
       gnu_result = convert (gnu_result_type, gnu_expr);
 
-      if (fp_arith_may_widen
+      if (TREE_CODE (gnu_result) != REAL_CST
+	  && fp_arith_may_widen
 	  && TYPE_PRECISION (gnu_result_type)
 	     < TYPE_PRECISION (longest_float_type_node))
 	{
@@ -2441,7 +2442,7 @@  Attribute_to_gnu (Node_Id gnat_node, tre
 	  finish_record_type (rec_type, field, 0, false);
 
 	  rec_val = build_constructor_single (rec_type, field, gnu_result);
-	  rec_val = save_expr (rec_val);
+	  rec_val = build1 (SAVE_EXPR, rec_type, rec_val);
 
 	  asm_expr
 	    = build5 (ASM_EXPR, void_type_node,