From 2bacf5a553d15779ab014623056011a71aff9355 Mon Sep 17 00:00:00 2001
From: Jacob Williams <jacobwilliams@users.noreply.github.com>
Date: Sat, 30 Dec 2023 09:58:40 -0600
Subject: [PATCH] readme update

---
 README.md | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/README.md b/README.md
index 8eb2fc9..3cbf4aa 100644
--- a/README.md
+++ b/README.md
@@ -18,6 +18,21 @@ fpm build --profile release
 fpm test --profile release
 ```
 
+By default, the library is built with single precision (`int32`) integer values. Explicitly specifying the integer kind can be done using the following processor flag:
+
+Preprocessor flag | Kind  | Number of bytes
+----------------- | ----- | ---------------
+`INT8`  | `integer(kind=int8)`  | 1
+`INT16` | `integer(kind=int16)` | 2
+`INT32` | `integer(kind=int32)` | 4
+`INT64` | `integer(kind=int64)` | 8
+
+For example, to build a long integer version of the library:
+
+```
+fpm build --profile release --flag "-DINT64"
+```
+
 ### Example
 
 A simple example is shown below: