From df2b78abd3a7c3727b7af1d7e79b2767cae0ecce Mon Sep 17 00:00:00 2001
From: Pradeep Garigipati <pradeep.garigipati@gmail.com>
Date: Mon, 25 Sep 2023 00:47:02 +0530
Subject: [PATCH] First set of changes to enable OneAPI backend

---
 examples/unified.rs | 7 +++++++
 src/core/array.rs   | 3 ++-
 src/core/backend.rs | 4 ++++
 src/core/defines.rs | 3 +++
 4 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/examples/unified.rs b/examples/unified.rs
index e70aa5d6d..5fa69b871 100644
--- a/examples/unified.rs
+++ b/examples/unified.rs
@@ -47,6 +47,13 @@ fn main() {
         test_backend();
     }
 
+    if available.contains(&Backend::ONEAPI) {
+        println!("Evaluating OneAPI Backend...");
+        set_backend(Backend::ONEAPI);
+        println!("There are {} OneAPI compute devices", device_count());
+        test_backend();
+    }
+
     if available.contains(&Backend::OPENCL) {
         println!("Evaluating OpenCL Backend...");
         set_backend(Backend::OPENCL);
diff --git a/src/core/array.rs b/src/core/array.rs
index 7ee6579ba..a444c0cd9 100644
--- a/src/core/array.rs
+++ b/src/core/array.rs
@@ -398,7 +398,8 @@ where
         match (err_val, ret_val) {
             (0, 1) => Backend::CPU,
             (0, 2) => Backend::CUDA,
-            (0, 3) => Backend::OPENCL,
+            (0, 4) => Backend::OPENCL,
+            (0, 8) => Backend::ONEAPI,
             _ => Backend::DEFAULT,
         }
     }
diff --git a/src/core/backend.rs b/src/core/backend.rs
index 2cc3749f4..eb1fbb628 100644
--- a/src/core/backend.rs
+++ b/src/core/backend.rs
@@ -35,6 +35,9 @@ pub fn get_available_backends() -> Vec<Backend> {
     HANDLE_ERROR(AfError::from(err_val));
 
     let mut b = Vec::new();
+    if temp & 0b1000 == 0b1000 {
+        b.push(Backend::ONEAPI);
+    }
     if temp & 0b0100 == 0b0100 {
         b.push(Backend::OPENCL);
     }
@@ -58,6 +61,7 @@ pub fn get_active_backend() -> Backend {
         (0, 1) => Backend::CPU,
         (0, 2) => Backend::CUDA,
         (0, 4) => Backend::OPENCL,
+        (0, 8) => Backend::ONEAPI,
         _ => panic!("Invalid backend retrieved, undefined behavior."),
     }
 }
diff --git a/src/core/defines.rs b/src/core/defines.rs
index b11662793..ffe27dc5e 100644
--- a/src/core/defines.rs
+++ b/src/core/defines.rs
@@ -66,11 +66,14 @@ pub enum Backend {
     CUDA = 2,
     /// OpenCL Compute Backend
     OPENCL = 4,
+    /// OneAPI Compute Backend
+    ONEAPI = 8,
 }
 
 impl Display for Backend {
     fn fmt(&self, f: &mut Formatter) -> Result<(), FmtError> {
         let text = match *self {
+            Backend::ONEAPI => "OneAPI",
             Backend::OPENCL => "OpenCL",
             Backend::CUDA => "Cuda",
             Backend::CPU => "CPU",