Online HelpPC 2.10 Quick Reference Utility Copyright 1991 David Jurgens
BSR - Bit Scan Reverse (386+ only)
Usage: BSR dest,src
Modifies flags: ZF
Scans source operand for first bit set. Sets ZF if a bit is found
set and loads the destination with an index to first set bit. Clears
ZF is no bits are found set. BSF scans forward across bit pattern
(0-n) while BSR scans in reverse (n-0).
Clocks Size
Operands 808x 286 386 486 Bytes
reg,reg - - 10+3n 6-103 3
reg,mem - - 10+3n 7-104 3-7
reg32,reg32 - - 10+3n 6-103 3-7
reg32,mem32 - - 10+3n 7-104 3-7
- see Instruction Timing
[helppc.bosbyte.nl] bsr