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HP OpenVMS RTL Library (LIB$) Manual
LIB$EMODH
On OpenVMS VAX systems, the Extended Multiply and Integerize routine
(H-Floating-Point Values) allows higher-level language users to perform
accurate range reduction of H-floating arguments.
This routine is not available to native OpenVMS Alpha programs but is
available to translated VAX images.
Format
LIB$EMODH floating-point-multiplier ,multiplier-extension
,floating-point-multiplicand ,integer-portion ,fractional-portion
RETURNS
| OpenVMS usage: |
cond_value |
| type: |
longword (unsigned) |
| access: |
write only |
| mechanism: |
by value |
Arguments
floating-point-multiplier
| OpenVMS usage: |
floating_point |
| type: |
H_floating |
| access: |
read only |
| mechanism: |
by reference |
The multiplier. The floating-point-multiplier argument
is an H-floating number.
multiplier-extension
| OpenVMS usage: |
word_unsigned |
| type: |
word (unsigned) |
| access: |
read only |
| mechanism: |
by reference |
The left-justified multiplier-extension bits. The
multiplier-extension argument is an unsigned word.
floating-point-multiplicand
| OpenVMS usage: |
floating_point |
| type: |
H_floating |
| access: |
read only |
| mechanism: |
by reference |
The multiplicand. The floating-point-multiplicand
argument is an H-floating number.
integer-portion
| OpenVMS usage: |
longword_signed |
| type: |
longword integer (signed) |
| access: |
write only |
| mechanism: |
by reference |
The integer portion of the result. The integer-portion
argument is the address of a signed longword integer containing the
integer portion of the result.
fractional-portion
| OpenVMS usage: |
floating_point |
| type: |
H_floating |
| access: |
write only |
| mechanism: |
by reference |
The fractional portion of the result. The
fractional-portion argument is an H-floating number.
Description
The floating-point multiplier extension operand (second operand) is
concatenated with the floating-point multiplier (first operand) to gain
x additional low-order fraction bits. The multiplicand is
multiplied by the extended multiplier. After multiplication, the
integer portion is extracted and a y-bit floating-point number
is formed from the fractional part of the product by truncating extra
bits.
The multiplication yields a result equivalent to the exact product
truncated to a fraction field of y bits. With respect to the
result as the sum of an integer and fraction of the same sign, the
integer operand is replaced by the integer part of the result and the
fraction operand is replaced by the rounded fractional part of the
result.
The values of x and y are as follows:
| Routine |
x |
Bits |
y |
|
LIB$EMODH
|
15
|
15:1
|
128
|
Condition Values Returned
|
SS$_NORMAL
|
Routine successfully completed.
|
|
SS$_FLTUND
|
Floating underflow. The integer and fraction operands are replaced by
zero.
|
|
SS$_INTOVF
|
Integer overflow. The integer operand is replaced by the low-order bits
of the true result. Floating overflow is indicated by SS$_INTOVF also.
|
|
SS$_ROPRAND
|
Reserved operand. The integer and fraction operands are unaffected.
|
LIB$EMODS (Alpha and I64 Only)
The Extended Multiply and Integerize routine (IEEE S-Floating-Point
Values) allows higher-level language users to perform accurate range
reduction of IEEE S-floating arguments.
Format
LIB$EMODS floating-point-multiplier ,multiplier-extension
,floating-point-multiplicand ,integer-portion ,fractional-portion
RETURNS
| OpenVMS usage: |
cond_value |
| type: |
longword (unsigned) |
| access: |
write only |
| mechanism: |
by value |
Arguments
floating-point-multiplier
| OpenVMS usage: |
floating_point |
| type: |
IEEE S_floating |
| access: |
read only |
| mechanism: |
by reference |
The multiplier. The floating-point-multiplier argument
is the address of an IEEE S-floating number containing the number.
multiplier-extension
| OpenVMS usage: |
byte_unsigned |
| type: |
byte (unsigned) |
| access: |
read only |
| mechanism: |
by reference |
The left-justified multiplier-extension bits. The
multiplier-extension argument is the address of an
unsigned byte containing these multiplier extension bits.
floating-point-multiplicand
| OpenVMS usage: |
floating_point |
| type: |
IEEE S_floating |
| access: |
read only |
| mechanism: |
by reference |
The multiplicand. The floating-point-multiplicand
argument is an IEEE S-floating number.
integer-portion
| OpenVMS usage: |
longword_signed |
| type: |
longword (signed) |
| access: |
write only |
| mechanism: |
by reference |
The integer portion of the result. The integer-portion
argument is the address of a signed longword integer containing the
integer portion of the result.
fractional-portion
| OpenVMS usage: |
floating_point |
| type: |
IEEE S_floating |
| access: |
write only |
| mechanism: |
by reference |
The fractional portion of the result. The
fractional-portion argument is the address of an IEEE
S-floating number containing the fractional portion of the result.
Description
LIB$EMODS allows higher-level language users to perform accurate range
reduction of IEEE S-floating arguments.
The floating-point multiplier-extension operand
(second operand) is concatenated with the
floating-point-multiplier (first operand) to gain
x additional low-order fraction bits. The multiplicand is
multiplied by the extended multiplier. After multiplication, the
integer portion is extracted and a y-bit floating-point number
is formed from the fractional part of the product by truncating extra
bits.
The multiplication yields a result equivalent to the exact product
truncated to a fraction field of y bits. With respect to the
result as the sum of an integer and fraction of the same sign, the
integer operand is replaced by the integer part of the result and the
fraction operand is replaced by the rounded fractional part of the
result.
The values of x and y are as follows:
| Routine |
x |
Bits |
y |
|
LIB$EMODS
|
8
|
7:0
|
32
|
Condition Values Returned
|
SS$_NORMAL
|
Routine successfully completed.
|
|
SS$_FLTUND
|
Floating underflow. The integer and fraction operands are replaced by
zero.
|
|
SS$_INTOVF
|
Integer overflow. The integer operand is replaced by the low-order bits
of the true result. Floating overflow is indicated by SS$_INTOVF also.
|
|
SS$_ROPRAND
|
Reserved operand. The integer and fraction operands are unaffected.
|
LIB$EMODT (Alpha and I64 Only)
The Extended Multiply and Integerize routine (IEEE T-Floating-Point
Values) allows higher-level language users to perform accurate range
reduction of IEEE T-floating arguments.
Format
LIB$EMODT floating-point-multiplier ,multiplier-extension
,floating-point-multiplicand ,integer-portion ,fractional-portion
RETURNS
| OpenVMS usage: |
cond_value |
| type: |
longword (unsigned) |
| access: |
write only |
| mechanism: |
by value |
Arguments
floating-point-multiplier
| OpenVMS usage: |
floating_point |
| type: |
IEEE T_floating |
| access: |
read only |
| mechanism: |
by reference |
The multiplier. The floating-point-multiplier argument
is the address of an IEEE T-floating number containing the number.
multiplier-extension
| OpenVMS usage: |
byte_unsigned |
| type: |
byte (unsigned) |
| access: |
read only |
| mechanism: |
by reference |
The left-justified multiplier-extension bits. The
multiplier-extension argument is the address of an
unsigned byte containing these multiplier extension bits.
floating-point-multiplicand
| OpenVMS usage: |
floating_point |
| type: |
IEEE T_floating |
| access: |
read only |
| mechanism: |
by reference |
The multiplicand. The floating-point-multiplicand
argument is an IEEE T-floating number.
integer-portion
| OpenVMS usage: |
longword_signed |
| type: |
longword (signed) |
| access: |
write only |
| mechanism: |
by reference |
The integer portion of the result. The integer-portion
argument is the address of a signed longword integer containing the
integer portion of the result.
fractional-portion
| OpenVMS usage: |
floating_point |
| type: |
IEEE T_floating |
| access: |
write only |
| mechanism: |
by reference |
The fractional portion of the result. The
fractional-portion argument is the address of an IEEE
T-floating number containing the fractional portion of the result.
Description
LIB$EMODT allows higher-level language users to perform accurate range
reduction of IEEE T-floating arguments.
The floating-point multiplier-extension operand
(second operand) is concatenated with the
floating-point-multiplier (first operand) to gain
x additional low-order fraction bits. The multiplicand is
multiplied by the extended multiplier. After multiplication, the
integer portion is extracted and a y-bit floating-point number
is formed from the fractional part of the product by truncating extra
bits.
The multiplication yields a result equivalent to the exact product
truncated to a fraction field of y bits. With respect to the
result as the sum of an integer and fraction of the same sign, the
integer operand is replaced by the integer part of the result and the
fraction operand is replaced by the rounded fractional part of the
result.
The values of x and y are as follows:
| Routine |
x |
Bits |
y |
|
LIB$EMODT
|
11
|
11:0
|
64
|
Condition Values Returned
|
SS$_NORMAL
|
Routine successfully completed.
|
|
SS$_FLTUND
|
Floating underflow. The integer and fraction operands are replaced by
zero.
|
|
SS$_INTOVF
|
Integer overflow. The integer operand is replaced by the low-order bits
of the true result. Floating overflow is indicated by SS$_INTOVF also.
|
|
SS$_ROPRAND
|
Reserved operand. The integer and fraction operands are unaffected.
|
LIB$EMUL
The Extended-Precision Multiply routine performs extended-precision
multiplication. LIB$EMUL makes the VAX EMUL instruction available as a
callable routine.
Note
On Alpha and I64 systems, OpenVMS Alpha and I64 instructions perform
the equivalent operation.
|
Format
LIB$EMUL longword-integer-multiplier ,longword-integer-multiplicand
,addend ,product
RETURNS
| OpenVMS usage: |
cond_value |
| type: |
longword (unsigned) |
| access: |
write only |
| mechanism: |
by value |
Arguments
longword-integer-multiplier
| OpenVMS usage: |
longword_signed |
| type: |
longword integer (signed) |
| access: |
read only |
| mechanism: |
by reference |
Multiplier used by LIB$EMUL in the extended-precision multiplication.
The longword-integer-multiplier argument is the
address of a signed longword integer containing the multiplier.
longword-integer-multiplicand
| OpenVMS usage: |
longword_signed |
| type: |
longword integer (signed) |
| access: |
read only |
| mechanism: |
by reference |
Multiplicand used by LIB$EMUL in the extended-precision multiplication.
The longword-integer-multiplicand argument is the
address of a signed longword integer containing the multiplicand.
addend
| OpenVMS usage: |
longword_signed |
| type: |
longword integer (signed) |
| access: |
read only |
| mechanism: |
by reference |
Addend used by LIB$EMUL in the extended-precision multiplication. The
addend argument is the address of a signed longword
integer containing the addend.
product
| OpenVMS usage: |
quadword_signed |
| type: |
quadword integer (signed) |
| access: |
write only |
| mechanism: |
by reference |
Product of the extended-precision multiplication. The
product argument is the address of a signed quadword
integer into which LIB$EMUL writes the product.
Description
The multiplicand argument is multiplied by the multiplier argument
giving a double-length result. The addend argument is sign-extended to
double-length and added to the result. LIB$EMUL then writes the result
into the product argument.
Condition Values Returned
|
SS$_NORMAL
|
Routine successfully completed.
|
|
|
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Example
|
INTEGER MULT1,MULT2,ADDEND,PRODUCT(2)
C+
C Find the extended precision multiplication of 268435456 times 4096.
C That is, find the extended precision product of 2**28 times 2**12.
C Since 268435456 times 4096 is 2**40, a quadword value is needed for
C the calculation: use LIB$EMUL.
C-
MULT1 = 4096
MULT2 = 268435456
APPEND = 0
C+
C Compute 268435456*4096.
C Note that product will be stored as a quadword. This value will be stored
C in the 2 dimensional vector PRODUCT. The first element of PRODUCT will
C contain the low order bits, while the second element will contain the high
C order bits.
C-
RETURN = LIB$EMUL(MULT1,MULT2,APPEND,PRODUCT)
TYPE *,'PRODUCT(2) =',PRODUCT(2),' and PRODUCT(1) = ',PRODUCT(1)
TYPE *,' '
TYPE *,'Note that 256 and 0 represent the hexadecimal value'
type *,14H'10000000000'x,', which in turn, represents 2**40.'
END
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This Fortran program demonstrates how to use LIB$EMUL. The output
generated by this program is as follows:
PRODUCT(2) = 256 and PRODUCT(1) = 0
|
Note that 256 and 0 represent the hexadecimal value '10000000000'x,
which in turn represents 240.
LIB$ENABLE_CTRL
The Enable CLI Interception of Control Characters routine requests the
calling process's command language interpreter (CLI) to resume
interception of the selected control characters when they are typed
during an interactive terminal session. LIB$ENABLE_CTRL provides the
same function as the DCL command SET CONTROL.
Format
LIB$ENABLE_CTRL enable-mask [,old-mask]
RETURNS
| OpenVMS usage: |
cond_value |
| type: |
longword (unsigned) |
| access: |
write only |
| mechanism: |
by value |
Arguments
enable-mask
| OpenVMS usage: |
mask_longword |
| type: |
longword (unsigned) |
| access: |
read only |
| mechanism: |
by reference |
Bit mask indicating for which control characters LIB$ENABLE_CTRL is to
enable interception. The enable-mask argument is the
address of an unsigned longword containing this bit mask. Each of the
32 bits corresponds to one of the 32 possible control characters. If a
bit is set, the corresponding control character is intercepted by the
CLI. Currently, only bits 20 and 25, corresponding to Ctrl/T and
Ctrl/Y, are recognized.
The following mask is defined in symbol libraries supplied by HP to
specify the value of enable-mask:
| Symbol |
Hex Value |
Function |
|
LIB$M_CLI_CTRLT
|
%X'00100000'
|
Enables Ctrl/T
|
|
LIB$M_CLI_CTRLY
|
%X'02000000'
|
Enables Ctrl/Y
|
If a set bit does not correspond to a character that the CLI can
intercept, an error is returned.
old-mask
| OpenVMS usage: |
mask_longword |
| type: |
longword (unsigned) |
| access: |
write only |
| mechanism: |
by reference |
Previous bit mask. The old-mask argument is the
address of an unsigned longword containing the old bit mask. The old
bit mask is of the same form as enable-mask.
Description
LIB$ENABLE_CTRL provides the functions of the DCL command SET CONTROL.
Normally, Ctrl/Y interrupts the current command, command procedure, or
image. After a call to LIB$DISABLE_CTRL, Ctrl/Y is treated like Ctrl/U
followed by a carriage return. LIB$ENABLE_CTRL restores the normal
operation of Ctrl/Y or Ctrl/T.
Both the DCL and MCR CLIs can intercept control characters. See the
HP OpenVMS DCL Dictionary for information on how the CLI processes control
characters.
LIB$ENABLE_CTRL is supported for use with the DCL or MCR CLIs.
If an image is run directly as a subprocess or as a detached process,
there is no CLI present to perform this function. In those cases, the
error status LIB$_NOCLI is returned.
Condition Values Returned
|
SS$_NORMAL
|
Routine successfully completed.
|
|
LIB$_INVARG
|
Invalid argument. A bit in
enable-mask was set which did not correspond to a
control character supported by the CLI.
|
|
LIB$_NOCLI
|
No CLI present. The calling process did not have a CLI to perform the
function, or the CLI did not support the request type. Note that an
image run as a subprocess or detached process does not have a CLI.
|
|
LIB$_UNECLIERR
|
Unexpected CLI error. The CLI returned an error status which was not
recognized. This error may be caused by use of a nonstandard CLI. If
this error occurs while using the DCL or MCR CLIs, please report the
problem to your HP support representative.
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