Seperate benchmarks by enabled features (#1538)

* Use cfg to seperate benchmark results based on features

* Remove allow pragma

* Avoid some unnecessary returns.

* Improve benchmarks layout

* Derive bench_name from actual device

* Run CPU benchmarks even when GPU feature is enabled

---------

Co-authored-by: Laurent <laurent.mazare@gmail.com>

4 files changed, 82 insertions, 13 deletions

diff --git a/candle-core/Cargo.toml b/candle-core/Cargo.toml
index 97857a6b..d9fc7526 100644
--- a/candle-core/Cargo.toml
+++ b/candle-core/Cargo.toml
@@ -46,6 +46,6 @@ accelerate = ["dep:libc", "dep:accelerate-src"]
 metal = ["dep:metal", "dep:candle-metal-kernels"]
 
 [[bench]]
-name = "matmul"
+name = "bench_main"
 harness = false
 
diff --git a/candle-core/benches/bench_main.rs b/candle-core/benches/bench_main.rs
new file mode 100644
index 00000000..4425f2fb
--- /dev/null
+++ b/candle-core/benches/bench_main.rs
@@ -0,0 +1,4 @@
+mod benchmarks;
+
+use criterion::criterion_main;
+criterion_main!(benchmarks::matmul::benches);
diff --git a/candle-core/benches/matmul.rs b/candle-core/benches/benchmarks/matmul.rs
index 83679771..9d67e642 100644
--- a/candle-core/benches/matmul.rs
+++ b/candle-core/benches/benchmarks/matmul.rs
@@ -1,25 +1,25 @@
+use crate::benchmarks::{BenchDevice, BenchDeviceHandler};
 use candle_core::{DType, Device, Tensor};
-use criterion::{black_box, criterion_group, criterion_main, Criterion, Throughput};
+use criterion::{black_box, criterion_group, Criterion, Throughput};
 use std::time::Instant;
 
 fn run(a: &Tensor, b: &Tensor) {
     a.matmul(&b.t().unwrap()).unwrap();
 }
 
-fn criterion_benchmark(c: &mut Criterion) {
+fn run_bench(c: &mut Criterion, device: &Device) {
     let b = 1;
     let m = 1;
     let n = 2048;
     let k = 2048;
 
-    let device = Device::new_metal(0).unwrap();
     let dtype = DType::F32;
-    let lhs = Tensor::zeros((b, m, k), dtype, &device).unwrap();
-    let rhs = Tensor::zeros((b, n, k), dtype, &device).unwrap();
+    let lhs = Tensor::zeros((b, m, k), dtype, device).unwrap();
+    let rhs = Tensor::zeros((b, n, k), dtype, device).unwrap();
 
     let flops = b * m * n * k;
 
-    let mut group = c.benchmark_group("matmul_metal");
+    let mut group = c.benchmark_group(device.bench_name("matmul"));
     group.throughput(Throughput::Bytes(flops as u64));
     group.bench_function("iter", move |b| {
         b.iter_custom(|iters| {
@@ -27,16 +27,18 @@ fn criterion_benchmark(c: &mut Criterion) {
             for _i in 0..iters {
                 run(black_box(&lhs), black_box(&rhs));
             }
-            if let Device::Metal(device) = &device {
-                device.wait_until_completed().unwrap();
-            } else {
-                panic!("Expected metal device");
-            }
+            device.sync().unwrap();
             start.elapsed()
         })
     });
     group.finish();
 }
 
+fn criterion_benchmark(c: &mut Criterion) {
+    let handler = BenchDeviceHandler::new().unwrap();
+    for device in handler.devices {
+        run_bench(c, &device);
+    }
+}
+
 criterion_group!(benches, criterion_benchmark);
-criterion_main!(benches);
diff --git a/candle-core/benches/benchmarks/mod.rs b/candle-core/benches/benchmarks/mod.rs
new file mode 100644
index 00000000..295bbabd
--- /dev/null
+++ b/candle-core/benches/benchmarks/mod.rs
@@ -0,0 +1,63 @@
+pub(crate) mod matmul;
+
+use candle_core::{Device, Result};
+
+pub(crate) trait BenchDevice {
+    fn sync(&self) -> Result<()>;
+
+    fn bench_name<S: Into<String>>(&self, name: S) -> String;
+}
+
+impl BenchDevice for Device {
+    fn sync(&self) -> Result<()> {
+        match self {
+            Device::Cpu => Ok(()),
+            Device::Cuda(device) => {
+                #[cfg(feature = "cuda")]
+                return Ok(device.synchronize()?);
+                #[cfg(not(feature = "cuda"))]
+                panic!("Cuda device without cuda feature enabled: {:?}", device)
+            }
+            Device::Metal(device) => {
+                #[cfg(feature = "metal")]
+                return Ok(device.wait_until_completed()?);
+                #[cfg(not(feature = "metal"))]
+                panic!("Metal device without metal feature enabled: {:?}", device)
+            }
+        }
+    }
+
+    fn bench_name<S: Into<String>>(&self, name: S) -> String {
+        match self {
+            Device::Cpu => {
+                let cpu_type = if cfg!(feature = "accelerate") {
+                    "accelerate"
+                } else if cfg!(feature = "mkl") {
+                    "mkl"
+                } else {
+                    "cpu"
+                };
+                format!("{}_{}", cpu_type, name.into())
+            }
+            Device::Cuda(_) => format!("cuda_{}", name.into()),
+            Device::Metal(_) => format!("metal_{}", name.into()),
+        }
+    }
+}
+
+struct BenchDeviceHandler {
+    devices: Vec<Device>,
+}
+
+impl BenchDeviceHandler {
+    pub fn new() -> Result<Self> {
+        let mut devices = Vec::new();
+        if cfg!(feature = "metal") {
+            devices.push(Device::new_metal(0)?);
+        } else if cfg!(feature = "cuda") {
+            devices.push(Device::new_cuda(0)?);
+        }
+        devices.push(Device::Cpu);
+        Ok(Self { devices })
+    }
+}