pTAL Conversion Guide

ManualsBrandsHP ManualsServerHP NonStop G-Series

191

192

193

194

195

196

197

198

199

200

Bit Operations

pTAL Conversion Guide—527302-002

14-4

Using 32-Bit Operands With Bit Deposit and Bit

Extract Operations

Using 32-Bit Operands With Bit Deposit and

Bit Extract Operations

TAL

You can perform bit extract and bit deposit operations only on 16-bit operands:

INT i;

INT j;

INT(32) k;

i := j.<12:15>; ! OK: j is 16 bits

i := k.<12:15>; ! ERROR: k is 32 bits

i := k.<28:31>; ! ERROR: k is 32 bits

You can reference any bits in an UNSIGNED(1-16) variable, even if the bits are not

declared in the variable’s declaration:

INT i;

UNSIGNED(4) j;

i := j.<12:15>; ! OK

i := j.< 7:11>; ! OK: TAL allows this,

! although only i contains only four bits

The TAL compiler issues a warning if a bit-extract operator accesses any of bits zero

through seven of a STRING field, but allows the reference:

INT i;

STRING j;

i := j.<8:15>; ! OK: i is 16 bits

i := j.<0:7>; ! OK: TAL issues a warning, but allows this,

! although only the low-order eight bits of i

! are defined

pTAL

You can perform bit extractions and deposits on 16-bit and 32-bit items. pTAL reports

an error, however, if you attempt to reference bits outside of the bits declared in the

variable’s declaration:

INT i;

UNSIGNED(4) j;

STRING k;

INT(32) l;

i := j.< 7:11>; ! ERROR: You can reference only

! bits 12 through 15 of j

i := k.<0:7>; ! ERROR: You can reference only

! bits 8 through 15 of k

i := l.<8:31>; ! OK: You can reference

! any of bits 0 through 31 of l