Ada Programming/Attributes/'Machine Emin

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Description

X'Machine_Emin is an Ada attribute where X is any floating point type.

Floating point types are represented as:

$sign\times mantissa\times radix^{exponent}$

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_Emin returns the smallest exponent.

Example

with Ada.Text_IO;

procedure Machine_Emin is

   package T_IO renames Ada.Text_IO;
   package I_IO is new  Ada.Text_IO.Integer_IO (Integer);
begin
   T_IO.Put ("Emin of Float type       = ");
   I_IO.Put (Float'Machine_Emin);
   T_IO.New_Line;
   
   T_IO.Put ("Emin of Long_Float type  = ");
   I_IO.Put (Long_Float'Machine_Emin);
   T_IO.New_Line;

end Machine_Emin;

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

Emin of Float type       =        -125
Emin of Long_Float type  =       -1021

See also

Wikibook

• Ada Programming
• Ada Programming/Attributes
• Ada Programming/Attributes/'Machine_Emax
• Ada Programming/Attributes/'Machine_Mantissa
• Ada Programming/Attributes/'Machine_Radix

Ada Reference Manual

• 5.3 Attributes of Floating Point Types (Annotated)
• Annex K Language-Defined Attributes (Annotated)