We define 54 macros for the powers of two >= 1024. We use six, in six
macro definitions. Four of them could just as well use the common MiB
macro, so do that. The remaining two can't, because they get passed
to stringify. Replace the macro by the literal number there.
Slightly harder to read in one instance (1048576 vs. S_1MiB), so add a
comment there. The other instance is a wash: 65536 vs S_64KiB. 65536
has been good enough for more than seven years there.
This effectively reverts commit 540b849261 and 1240ac558d.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The lookup table for power-of-two sizes was added in commit 540b849261
for the purpose of having convenient shortcuts for these sizes in cases
when the literal number has to be present at compile time, and
expressions as '(1 * KiB)' can not be used. One such case is the
stringification of sizes. Beyond that, it is convenient to use these
shortcuts for all power-of-two sizes, even if they don't have to be
literal numbers.
Despite its convenience, this table introduced 55 lines of "dumb" code,
the purpose and origin of which are obscure without reading the message
of the commit which introduced it. This patch fixes that by adding a
comment to the code itself with a brief explanation for the reasoning
behind this table. This comment includes the short AWK script that
generated the table, so that anyone who's interested could make sure
that the values in it are correct (otherwise these values look as if
they were typed manually).
Signed-off-by: Leonid Bloch <lbloch@janustech.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Adding a lookup table for the powers of two, with the appropriate size
prefixes. This is needed when a size has to be stringified, in which
case something like '(1 * KiB)' would become a literal '(1 * (1L << 10))'
string. Powers of two are used very often for sizes, so such a table
will also make it easier and more intuitive to write them.
This table is generatred using the following AWK script:
BEGIN {
suffix="KMGTPE";
for(i=10; i<64; i++) {
val=2**i;
s=substr(suffix, int(i/10), 1);
n=2**(i%10);
pad=21-int(log(n)/log(10));
printf("#define S_%d%siB %*d\n", n, s, pad, val);
}
}
Signed-off-by: Leonid Bloch <lbloch@janustech.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Loosely based on 076b35b5a5.
Suggested-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20180625124238.25339-2-f4bug@amsat.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
