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authorKarl Williamson <public@khwilliamson.com>2011-09-24 11:29:09 -0600
committerKarl Williamson <public@khwilliamson.com>2011-10-01 09:58:08 -0600
commit3912bc886c99be4f8599922a1998dcf2cfffe877 (patch)
tree92dc953bad35ce426a7a8f96f24be2ee8796f816 /handy.h
parent94b42e47713770173606e6b7686a6ca5b74b41cc (diff)
downloadperl-3912bc886c99be4f8599922a1998dcf2cfffe877.tar.gz
handy.h: clarify, typos in comment
Diffstat (limited to 'handy.h')
-rw-r--r--handy.h19
1 files changed, 10 insertions, 9 deletions
diff --git a/handy.h b/handy.h
index 5e30512104..3f04b56331 100644
--- a/handy.h
+++ b/handy.h
@@ -562,15 +562,16 @@ patched there. The file as of this writing is cpan/Devel-PPPort/parts/inc/misc
*/
-/* FITS_IN_8_BITS(c) returns true if c occupies no more than 8 bits. It is
- * designed to be hopefully bomb-proof, making sure that no bits of
- * information are lost even on a 64-bit machine, but to get the compiler to
- * optimize it out if possible. This is because Configure makes sure that the
- * machine has an 8-bit byte, so if c is stored in a byte, the sizeof()
- * guarantees that this evaluates to a constant true at compile time. The use
- * of the mask instead of '< 256' keeps gcc from complaining that it is alway
- * true, when c's storage class is a byte. Use U64TYPE because U64 is known
- * only in the perl core, and this macro can be called from outside that */
+/* FITS_IN_8_BITS(c) returns true if c doesn't have a bit set other than in
+ * the lower 8. It is designed to be hopefully bomb-proof, making sure that no
+ * bits of information are lost even on a 64-bit machine, but to get the
+ * compiler to optimize it out if possible. This is because Configure makes
+ * sure that the machine has an 8-bit byte, so if c is stored in a byte, the
+ * sizeof() guarantees that this evaluates to a constant true at compile time.
+ * The use of the mask instead of '< 256' keeps gcc from complaining that it is
+ * always true, when c's storage class is a byte. Use U64TYPE because U64 is
+ * known only in the perl core, and this macro can be called from outside that
+ */
#ifdef HAS_QUAD
# define FITS_IN_8_BITS(c) ((sizeof(c) == 1) || (((U64TYPE)(c) & 0xFF) == (U64TYPE)(c)))
#else