View source for Ada Programming/Attributes/'Machine Emax

{{Ada/Navigation|Attributes|'Machine_Emax}}
__TOC__

== Description ==

X'Machine_Emax is an Ada [[Ada Programming/Attributes|attribute]] where X is any floating point type.

Floating point types are represented as:

:<math>sign \times mantissa \times radix^{exponent}</math>

where

:sign is 1 or -1
:
:mantissa is a fraction in base radix
:
:radix is the hardware radix (usually 2)
:
:exponent is an integer

'Machine_Emax returns the largest exponent.

== Example ==

 {{Ada/keyword|with}} {{Ada/package|Ada|Text_IO}}{{Ada/delimiter|;}}
 
 {{Ada/keyword|procedure}} Machine_Emax {{Ada/keyword|is}}
 
    {{Ada/keyword|package}} T_IO {{Ada/keyword|renames}} Ada{{Ada/delimiter|dot|.}}Text_IO{{Ada/delimiter|;}}
    {{Ada/keyword|package}} I_IO {{Ada/keyword|is}} {{Ada/keyword|new}}  Ada{{Ada/delimiter|dot|.}}Text_IO{{Ada/delimiter|dot|.}}Integer_IO {{Ada/delimiter|(}}Integer{{Ada/delimiter|)}}{{Ada/delimiter|;}}
 {{Ada/keyword|begin}}
    T_IO{{Ada/delimiter|dot|.}}Put {{Ada/delimiter|(}}"Emax of Float type       = "{{Ada/delimiter|)}}{{Ada/delimiter|;}}
    I_IO{{Ada/delimiter|dot|.}}Put {{Ada/delimiter|(}}Float{{Ada/delimiter|'}}{{Ada/attribute|Machine_Emax}}{{Ada/delimiter|)}}{{Ada/delimiter|;}}
    T_IO{{Ada/delimiter|dot|.}}New_Line{{Ada/delimiter|;}}
    
    T_IO{{Ada/delimiter|dot|.}}Put {{Ada/delimiter|(}}"Emax of Long_Float type  = "{{Ada/delimiter|)}}{{Ada/delimiter|;}}
    I_IO{{Ada/delimiter|dot|.}}Put {{Ada/delimiter|(}}Long_Float{{Ada/delimiter|'}}{{Ada/attribute|Machine_Emax}}{{Ada/delimiter|)}}{{Ada/delimiter|;}}
    T_IO{{Ada/delimiter|dot|.}}New_Line{{Ada/delimiter|;}}
 
 {{Ada/keyword|end}} Machine_Emax{{Ada/delimiter|;}}

The output with GNAT 4.6 on the x86-64 architecture is:

 Emax of Float type       =         128
 Emax of Long_Float type  =        1024

== See also ==

=== Wikibook ===

* [[Ada Programming]]
* [[Ada Programming/Attributes]]
* [[Ada Programming/Attributes/'Machine_Emin]]
* [[Ada Programming/Attributes/'Machine_Mantissa]]
* [[Ada Programming/Attributes/'Machine_Radix]]

=== Ada Reference Manual ===

* {{Ada/RM2|5|3|Attributes of Floating Point Types}}
* {{Ada/RMA1|K|Language-Defined Attributes}}


[[{{BOOKCATEGORY|Ada Programming}}|Address]]
[[{{BOOKCATEGORY|Ada Programming}}/Representation attributes|Address]]