Integer comparison: Difference between revisions

=={{header|EDSAC order code}}==

The EDSAC offers two conditional branching orders, <tt>E</tt> (branch if the accumulator >= 0) and <tt>G</tt> (branch if the accumulator < 0). Testing for equality thus requires two operations.

<lang edsac>[ Integer comparison

==================

A program for the EDSAC

Illustrates the use of the E

(branch on accumulator sign

bit clear) and G (branch on

accumulator sign bit set)

orders

The integers to be tested, x

and y, should be stored in

addresses 13@ and 14@

Output: the program causes the

machine to print

'+' if x > y,

'=' if x = y,

'-' if x < y.

Works with Initial Orders 2 ]

T56K [ load point ]

GK [ base address ]

O15@ [ figure shift ]

A13@ [ a = x ]

S14@ [ a -= y ]

G10@ [ if a<0 go to 10 ]

S12@ [ a -= 1 ]

E8@ [ if a>=0 go to 8 ]

O17@ [ write '=' ]

ZF [ halt ]

[ 8 ] O16@ [ write '+' ]

ZF [ halt ]

[ 10 ] O18@ [ write '-' ]

ZF [ halt ]

[ 12 ] P0D [ const: 1 ]

[ 13 ] P16D [ x = 37 ]

[ 14 ] P14F [ y = 28 ]

[ 15 ] #F [ figure shift ]

[ 16 ] ZF [ + character ]

[ 17 ] VF [ = character ]

[ 18 ] AF [ - character ]

EZPF [ begin execution ]</lang>