User guide

9.2. THE CINTCODE INSTRUCTION SET 169
9.2.11 Floating-point Instructions
Floating-point operations other than those performed by SELST are provided by the
FLTOP instruction. They are as follows.
FLTOP 1 b A := floating point(A × 10
b
)
FLTOP 3 A := FLOAT A
FLTOP 4 A := FIX A
FLTOP 5 A := #ABS A
FLTOP 6 A := A #* B
FLTOP 7 A := A #/ B
FLTOP 8 A := A #+ B
FLTOP 9 A := A #- B
FLTOP 10 A := #+A
FLTOP 11 A := #-A
FLTOP 12 A := A #= B
FLTOP 13 A := A #~= B
FLTOP 14 A := A #< B
FLTOP 15 A := A #> B
FLTOP 16 A := A #<= B
FLTOP 17 A := A #>= B
In the above table, b is a signed byte representing a decimal exponent in the range -128
to +127. F l oating point numbers with exponents outside this range can be generated
using sys(Sys
flt, fl mk, x, e) as described on page 3.3.
9.2.12 Select Instructions
Access to fields and some o p:= assignment are performed using the following instruc-
tions.
SELLD len sh A := SLCT len:sh:0 OF A
SELST 0 len s h SLCT len:sh:0 OF A := B
SELST op len sh SLCT len:sh:0 OF A op:= B
The mapping between op and its corresponding expression operator is given by the
table on page 149.
9.2.13 Undefined Instructions
There in now only one undefined instruction and it code is 0. It will caus e the interpreter
to return with exception code of 1.