http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52661
Bug #: 52661
Summary: negative maxint for long long gives warning
Classification: Unclassified
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: jmich...@yahoo.com
Created attachment 26948
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=26948
maxint64-bug.cpp, the code which causes the warning
I have tried outputting with <iostream> and I get correct output.
but I get a compiler warning if I use the following constant:
-9223372036854775808LL
//maxint64-bug.cpp
//#include <iostream>
int main(void) {
long long ll=-9223372036854775808LL;
//std::cout<<ll;
return 0;
}
/*
g++ compiles with warning I should not get...
Wed 03/21/2012
22:19:23.42|C:\prj\test\mingw-w64\maxint64-bug|>c:\mingw-w32-bin_i686-mingw_20111127\bin\i686-w64-mingw32-g++.exe
-ls
tdc++ -Wall -W -Wextra -Xlinker -Map=maxint64-bug.map -std=c++11 -Ofast -o
"maxint64-bug.exe" "maxint64-bug.cpp" 2>"errmaxint64-bug"
Wed 03/21/2012 22:19:26.01|C:\prj\test\mingw-w64\maxint64-bug|>type
"errmaxint64-bug"
maxint64-bug.cpp:3:19: warning: integer constant is so large that it is
unsigned [enabled by default]
this bug is in 4.6.2 as well as 4.7.0
this number is a valid integer within the long long range. but it is on the
boundary.
the valid range of a long long is -9223372036854775808LL..9223372036854775807LL
or -(2^(64-1))..(2^(64-1)-1)
you can verify this with ttcalc. you can do this with 32-bit and 16-bit and
8-bit signed integers, for instance,
int or long: -(2^(32-1))..(2^(32-1)-1)
short: -(2^(16-1))..(2^(16-1)-1)
char: -(2^(8-1))..(2^(8-1)-1)
THOSE RANGES WORK. this particular constant does NOT.
*/
