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[Ada] Fix wrong code with biased subtype
- From: Eric Botcazou <ebotcazou at adacore dot com>
- To: gcc-patches at gcc dot gnu dot org
- Date: Mon, 10 Oct 2016 10:53:30 +0200
- Subject: [Ada] Fix wrong code with biased subtype
- Authentication-results: sourceware.org; auth=none
This is a regression present on all active branches for a subtype of a biased
type declared with explicit constraints, which is itself biased. The compiler
generates code that computes a wrong value for the conversion to an integer.
Tested on x86_64-suse-linux, applied on all active branches.
2016-10-10 Eric Botcazou <ebotcazou@adacore.com>
* gcc-interface/utils.c (convert): For a biased input type, convert
the bias itself to the base type before adding it.
2016-10-10 Eric Botcazou <ebotcazou@adacore.com>
* gnat.dg/biased_subtype.adb: New test.
--
Eric Botcazou
Index: gcc-interface/utils.c
===================================================================
--- gcc-interface/utils.c (revision 240890)
+++ gcc-interface/utils.c (working copy)
@@ -4193,12 +4193,15 @@ convert (tree type, tree expr)
return convert (type, unpadded);
}
- /* If the input is a biased type, adjust first. */
+ /* If the input is a biased type, convert first to the base type and add
+ the bias. Note that the bias must go through a full conversion to the
+ base type, lest it is itself a biased value; this happens for subtypes
+ of biased types. */
if (ecode == INTEGER_TYPE && TYPE_BIASED_REPRESENTATION_P (etype))
return convert (type, fold_build2 (PLUS_EXPR, TREE_TYPE (etype),
fold_convert (TREE_TYPE (etype), expr),
- fold_convert (TREE_TYPE (etype),
- TYPE_MIN_VALUE (etype))));
+ convert (TREE_TYPE (etype),
+ TYPE_MIN_VALUE (etype))));
/* If the input is a justified modular type, we need to extract the actual
object before converting it to any other type with the exceptions of an
@@ -4502,7 +4505,12 @@ convert (tree type, tree expr)
&& (ecode == ARRAY_TYPE || ecode == UNCONSTRAINED_ARRAY_TYPE
|| (ecode == RECORD_TYPE && TYPE_CONTAINS_TEMPLATE_P (etype))))
return unchecked_convert (type, expr, false);
- else if (TYPE_BIASED_REPRESENTATION_P (type))
+
+ /* If the output is a biased type, convert first to the base type and
+ subtract the bias. Note that the bias itself must go through a full
+ conversion to the base type, lest it is a biased value; this happens
+ for subtypes of biased types. */
+ if (TYPE_BIASED_REPRESENTATION_P (type))
return fold_convert (type,
fold_build2 (MINUS_EXPR, TREE_TYPE (type),
convert (TREE_TYPE (type), expr),
-- { dg-do run }
-- { dg-options "-gnatws" }
procedure Biased_Subtype is
CIM_Max_AA : constant := 9_999_999;
CIM_Min_AA : constant := -999_999;
type TIM_AA is range CIM_Min_AA..CIM_Max_AA + 1;
for TIM_AA'Size use 24;
subtype STIM_AA is TIM_AA range TIM_AA(CIM_Min_AA)..TIM_AA(CIM_Max_AA);
SAA : STIM_AA := 1;
begin
if Integer(SAA) /= 1 then
raise Program_Error;
end if;
end;