Quick question: Is there any particular reason why the system function ror() (in /fpc/rtl/inc/systemh.inc) has been divided up into rorbyte, rordword and rorqword (and respectively for rol() ) instead of being overloaded?
Mailing lists / fpc-pascal / 2009-10
Question about ror / rordword...
3 messages · 2 people ·
- Michael Green 2
- Florian Klaempfl 1
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Quick question: Is there any particular reason why the system function ror() (in /fpc/rtl/inc/systemh.inc) has been divided up into rorbyte, rordword and rorqword (and respectively for rol() ) instead of being overloaded?
Ror/rol are very sensitive against data type changes so this ensures you get always the desired result. While x shr 1 has the same result if the value fits in x, ror(x,1) has different results if x is a byte, word or dword even if it's value is e.g. 1.
Makes perfect sense, thanks for the quick answer :-)
Florian Klaempfl wrote 5 lines
Ror/rol are very sensitive against data type changes so this ensures you
get always the desired result. While x shr 1 has the same result if the
value fits in x, ror(x,1) has different results if x is a byte, word or
dword even if it's value is e.g. 1.