http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47821
Summary: BUG: warning: left shift count >= width of type
Product: gcc
Version: 4.1.2
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: nfav...@uwo.ca
Created attachment 23409
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=23409
Example c program for UltraSPARC producing incorrect results with left shift
While developing a 64bit program for the UltraSPARC,
I was warned shifting 56 times left was >= width of type
See attachment code.
Since you may not be able to run it,
here is the output:
sizeof 'k' is 4
sizeof 'kk' is 8
sizeof 'B' is 1
B = 2c (hex)
2c000000 <-----This is not correct!
The last line should be:
2c00000000000000 <-----This is correct (32 bits more)
The issue here is this:
kk is a long int (64 bits)
and compiling produces a warning:
(at line 39): warning: left shift count >= width of type
Line 39 is:
kk = (B << 56); // place B in bit position 63..56 of 64 bits
This warning is incorrect.
-AND-
The compiled code is incorrect.
-NF
