http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60730
Bug ID: 60730
Summary: 'Round of a fixed point type incorrectly truncates its
operand instead of rounding it
Product: gcc
Version: 4.9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: ada
Assignee: unassigned at gcc dot gnu.org
Reporter: georggcc at googlemail dot com
Created attachment 32517
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=32517&action=edit
full program text
The program below raises, but should not; LRM 3.5.10 says
that Centi'Round should round away from 0 in the case
presented here.
The program attached to this report tries to reflect the
discussion in comp.lang.ada that started on 22nd of Jan 2014,
"How to round to the nearest fixed-point value".
The effect seen has been classified as a compiler bug: the
program should run as is, with no output. Instead, it raises
Program_Error because the value of 0.999, supposedly
rounded to 3 digits in `Rounded`, is not 1.00, but 0.99.
$ gnatmake -gnatv -gnatwa round_decimal
gcc -c -gnatv -gnatwa round_decimal.adb
GNAT 4.9.0 20140331 (experimental)
Copyright 1992-2014, Free Software Foundation, Inc.
Compiling: round_decimal.adb (source file time stamp: 2014-04-01 15:39:04)
38 lines: No errors
gnatbind -x round_decimal.ali
gnatlink round_decimal.ali
$ ./round_decimal
raised PROGRAM_ERROR : round_decimal.adb:35 explicit raise
