Developer Reference

  • 2020.2
  • 07/15/2020
  • Public Content
Contents

?lamc5

Called from
?lamc2
. Attempts to compute the largest machine floating-point number, without overflow.

Syntax

call slamc5
(
beta
,
p
,
emin
,
ieee
,
emax
,
rmax
)
call dlamc5
(
beta
,
p
,
emin
,
ieee
,
emax
,
rmax
)
Include Files
  • mkl.fi
Description
The routine
?lamc5
attempts to compute
rmax
, the largest machine floating-point number, without overflow. It assumes that
emax
+ abs(
emin
)
sum approximately to a power of 2. It will fail on machines where this assumption does not hold, for example, the Cyber 205 (
emin
= -28625
,
emax
= 28718
). It will also fail if the value supplied for
emin
is too large (that is, too close to zero), probably with overflow.
Input Parameters
beta
INTEGER
. The base of floating-point arithmetic.
p
INTEGER
. The number of base
beta
digits in the mantissa of a floating-point value.
emin
INTEGER
. The minimum exponent before (gradual) underflow.
ieee
LOGICAL
. A logical flag specifying whether or not the arithmetic system is thought to comply with the IEEE standard.
Output Parameters
emax
INTEGER
. The largest exponent before overflow.
rmax
REAL
for
slamc5
DOUBLE PRECISION
for
dlamc5
The largest machine floating-point number.

Product and Performance Information

1

Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice.

Notice revision #20110804