https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120609
Bug ID: 120609
Summary: printf fails for a decimal type if variable is
unmodified
Product: gcc
Version: 13.3.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: madams846 at hotmail dot com
Target Milestone: ---
Created attachment 61609
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=61609&action=edit
.i file
Printing a decimal data type value that is unmodified fails. Printout fail --
and success with variable modifications -- is the same for Decimal32, Decimal64
and Decimal128. I discovered this bug in a larger program. I was preparing a
test case to report another bug with decimal data type.
Simple program decBugDemo.c :
#include <stdio.h>
int main() {
_Decimal64 value1 = 2.0dd ;
printf("\n %7.7De \n\n", value1 );
return 0 ;
}
compiled with "gcc decBugDemo.c -ldfp" prints out “%7.7De”.
Same program with an operation:
_Decimal64 value1= 2.0dd ;
_Decimal64 value2= 2.0dd;
value1 += value2;
printf("\n %7.7De \n\n", value1 );
prints out "4.0000000e+00" with no optimization option or with "-O0", but
again prints out “%7.7De” with any other optimization level -O123 or -Ofast.
Same program with one variable global
#include <stdio.h>
_Decimal64 value2= 2.0dd ;
int main() {
_Decimal64 value1= 2.0dd ;
value1 += value2;
printf("\n %7.7De \n\n", value1 );
return 0 ;
}
prints out "4.0000000e+00" with any optimization level.
My gcc version is (Ubuntu 13.3.0-6ubuntu2~24.04) 13.3.0 using WSL on Windows
11 Home 24H2 OS build 26100.4202 running on 11th Gen Intel(R) Core(TM)
i5-1135G7 @ 2.40GHz .
