The function Build_Conversion in Exp_Fixd does a bit of folding but
fails to preserve the Conversion_OK flag in doing so, unlike other
flags.
Tested on x86_64-pc-linux-gnu, committed on trunk
2020-06-17 Eric Botcazou <ebotca...@adacore.com>
gcc/ada/
* exp_fixd.adb (Build_Conversion): Also preserve the
Conversion_OK flag of an inner conversion.--- gcc/ada/exp_fixd.adb
+++ gcc/ada/exp_fixd.adb
@@ -262,7 +262,8 @@ package body Exp_Fixd is
-- Remove inner conversion if both inner and outer conversions are
-- to integer types, since the inner one serves no purpose (except
-- perhaps to set rounding, so we preserve the Rounded_Result flag)
- -- and also we preserve the range check flag on the inner operand
+ -- and also preserve the Conversion_OK and Do_Range_Check flags of
+ -- the inner conversion.
if Is_Integer_Type (Typ)
and then Is_Integer_Type (Etype (Expr))
@@ -273,6 +274,7 @@ package body Exp_Fixd is
Subtype_Mark => New_Occurrence_Of (Typ, Loc),
Expression => Expression (Expr));
Set_Rounded_Result (Result, Rounded_Result_Set (Expr));
+ Set_Conversion_OK (Result, Conversion_OK (Expr));
Rcheck := Rcheck or Do_Range_Check (Expr);
-- For all other cases, a simple type conversion will work
