Commit f274e125 authored by Raymond Toy's avatar Raymond Toy

Fix some bad markup

parent 64e5f754
......@@ -181,8 +181,7 @@ For a more detailed list of issues and notes, see src/NOTES.
We highlight just a few issues here.
o Block data statements.
* Block data statements.
In Fortran, block data statments are used to initialize common
blocks. Since Fortran executables are loaded and run just once,
this is not a problem. However, in Lisp, this might not be true,
......@@ -190,8 +189,7 @@ o Block data statements.
up to you to run the block data initializer at the right time, as
needed. f2cl cannot know when and where to call the initializer.
o Common blocks.
* Common blocks.
F2cl converts common blocks to structures. However, common blocks
may be referenced in several different files, so the user must
tell f2cl when to define the structure. Use the :declare-common
......@@ -204,13 +202,13 @@ o Common blocks.
changes how f2cl handles common blocks. A rather common use of
common blocks has the same common block using different variable
names. For example, one routine might have
```
COMMON /foo/ a(10), b, i(4)
```
and another might say
```
COMMON /foo/ b(9), c, d, j(2), k(2)
```
In Fortran, this is perfectly acceptable. Normally, f2cl expects
all common blocks to use the same variable names, and then f2cl
creates a structure for the common block using the variable names
......@@ -218,11 +216,11 @@ o Common blocks.
f2cl gets confused. Hence, :common-as-array. We treat the common
block as an array of memory. So this gets converted into a
structure somewhat like
```
(defstruct foo
(part-0 (make-array 11 :element-type 'real))
(part-1 (make-array 4 :element-type 'integer4)))
```
(In a more general case, we group all contiguous variables of the
same type into one array. f2cl and Lisp cannot handle the case
where a real and integer value are allocated to the same piece of
......@@ -231,7 +229,7 @@ o Common blocks.
Then in the individual routines, symbol-macrolets are used to
create accessors for the various definitions. Hence, for the
second version, we would do something like
```
(symbol-macrolet
(b (make-array 9 :displaced-to
(foo-part-0 *foo*)
......@@ -245,15 +243,14 @@ o Common blocks.
(foo-part-1 *foo*)
:displaced-offset 2))
...)
```
Thus, we access the right parts of the common block, independent
of the name. Note that this has a performance impact since we
used displaced arrays.
o Conversion order.
* Conversion order.
While not necessary, f2cl can do a significantly better job in
generating code if the functions are compiled in the correct
order. This means any function, F, that is called by another
......
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