Use proper "abs" function returning a real for comparing magnitude of
elements. The previous local implementation using "-" only was correct
for real values. This prepares for the pure Ada reimplementation of
Generic_Complex_Arrays.
Tested on x86_64-pc-linux-gnu, committed on trunk
2011-10-13 Geert Bosch <bo...@adacore.com>
* s-gearop.ads (Forward_Eliminate): Add "abs" formal function
returning a Real.
* s-gearop.adb (Forward_Eliminate): Remove local "abs" function
and use formal.
* a-ngrear.adb (Forward_Eliminate): Adjust instantiation for
new profile.
Index: a-ngrear.adb
===================================================================
--- a-ngrear.adb (revision 179909)
+++ a-ngrear.adb (working copy)
@@ -33,7 +33,7 @@
-- reason for this is new Ada 2012 requirements that prohibit algorithms such
-- as Strassen's algorithm, which may be used by some BLAS implementations. In
-- addition, some platforms lacked suitable compilers to compile the reference
--- BLAS/LAPACK implementation. Finally, on many platforms there may be more
+-- BLAS/LAPACK implementation. Finally, on some platforms there are be more
-- floating point types than supported by BLAS/LAPACK.
with Ada.Containers.Generic_Anonymous_Array_Sort; use Ada.Containers;
@@ -59,6 +59,7 @@
procedure Forward_Eliminate is new Ops.Forward_Eliminate
(Scalar => Real'Base,
+ Real => Real'Base,
Matrix => Real_Matrix,
Zero => 0.0,
One => 1.0);
Index: s-gearop.adb
===================================================================
--- s-gearop.adb (revision 179909)
+++ s-gearop.adb (working copy)
@@ -161,9 +161,6 @@
pragma Assert (M'First (1) = N'First (1) and then
M'Last (1) = N'Last (1));
- function "abs" (X : Scalar) return Scalar is
- (if X < Zero then Zero - X else X);
-
-- The following are variations of the elementary matrix row operations:
-- row switching, row multiplication and row addition. Because in this
-- algorithm the addition factor is always a negated value, we chose to
@@ -274,14 +271,14 @@
for J in M'Range (2) loop
declare
Max_Row : Integer := Row;
- Max_Abs : Scalar := Zero;
+ Max_Abs : Real'Base := 0.0;
begin
-- Find best pivot in column J, starting in row Row
for K in Row .. M'Last (1) loop
declare
- New_Abs : constant Scalar := abs M (K, J);
+ New_Abs : constant Real'Base := abs M (K, J);
begin
if Max_Abs < New_Abs then
Max_Abs := New_Abs;
@@ -290,7 +287,7 @@
end;
end loop;
- if Zero < Max_Abs then
+ if Max_Abs > 0.0 then
Switch_Row (M, N, Row, Max_Row);
Divide_Row (M, N, Row, M (Row, J));
Index: s-gearop.ads
===================================================================
--- s-gearop.ads (revision 179909)
+++ s-gearop.ads (working copy)
@@ -65,12 +65,14 @@
generic
type Scalar is private;
+ type Real is digits <>;
type Matrix is array (Integer range <>, Integer range <>) of Scalar;
+ with function "abs" (Right : Scalar) return Real'Base is <>;
with function "-" (Left, Right : Scalar) return Scalar is <>;
with function "*" (Left, Right : Scalar) return Scalar is <>;
with function "/" (Left, Right : Scalar) return Scalar is <>;
- with function "<" (Left, Right : Scalar) return Boolean is <>;
- Zero, One : Scalar;
+ Zero : Scalar;
+ One : Scalar;
procedure Forward_Eliminate
(M : in out Matrix;
N : in out Matrix;
