Add some 'cuda-if-available' helper function. (#172)

candle-core/src/device.rs

@@ -109,6 +109,14 @@ impl Device {
         }
     }
 
+    pub fn cuda_if_available(ordinal: usize) -> Result<Self> {
+        if crate::utils::cuda_is_available() {
+            Self::new_cuda(ordinal)
+        } else {
+            Ok(Self::Cpu)
+        }
+    }
+
     pub(crate) fn rand_uniform(
         &self,
         shape: &Shape,

candle-core/src/utils.rs

@@ -17,3 +17,10 @@ pub fn has_mkl() -> bool {
     #[cfg(not(feature = "mkl"))]
     return false;
 }
+
+pub fn cuda_is_available() -> bool {
+    #[cfg(feature = "cuda")]
+    return true;
+    #[cfg(not(feature = "cuda"))]
+    return false;
+}

candle-examples/examples/bert/main.rs

@@ -495,20 +495,7 @@ struct Args {
 
 impl Args {
     fn build_model_and_tokenizer(&self) -> Result<(BertModel, Tokenizer)> {
-        #[cfg(feature = "cuda")]
-        let default_device = Device::new_cuda(0)?;
-
-        #[cfg(not(feature = "cuda"))]
-        let default_device = {
-            println!("Running on CPU, to run on GPU, run this example with `--features cuda`");
-            Device::Cpu
-        };
-
-        let device = if self.cpu {
-            Device::Cpu
-        } else {
-            default_device
-        };
+        let device = candle_examples::device(self.cpu)?;
         let default_model = "sentence-transformers/all-MiniLM-L6-v2".to_string();
         let default_revision = "refs/pr/21".to_string();
         let (model_id, revision) = match (self.model_id.to_owned(), self.revision.to_owned()) {

candle-examples/examples/falcon/main.rs

@@ -120,20 +120,7 @@ struct Args {
 fn main() -> Result<()> {
     let args = Args::parse();
 
-    #[cfg(feature = "cuda")]
-    let default_device = Device::new_cuda(0)?;
-
-    #[cfg(not(feature = "cuda"))]
-    let default_device = {
-        println!("Running on CPU, to run on GPU, run this example with `--features cuda`");
-        Device::Cpu
-    };
-    let device = if args.cpu {
-        Device::Cpu
-    } else {
-        default_device
-    };
-
+    let device = candle_examples::device(args.cpu)?;
     let start = std::time::Instant::now();
     let api = Api::new()?;
     let repo = Repo::with_revision(args.model_id, RepoType::Model, args.revision);

candle-examples/examples/llama/main.rs

@@ -134,20 +134,7 @@ fn main() -> Result<()> {
 
     let args = Args::parse();
 
-    #[cfg(feature = "cuda")]
-    let default_device = Device::new_cuda(0)?;
-
-    #[cfg(not(feature = "cuda"))]
-    let default_device = {
-        println!("Running on CPU, to run on GPU, run this example with `--features cuda`");
-        Device::Cpu
-    };
-
-    let device = if args.cpu {
-        Device::Cpu
-    } else {
-        default_device
-    };
+    let device = candle_examples::device(args.cpu)?;
     let config = Config::config_7b();
     let cache = model::Cache::new(!args.no_kv_cache, &config, &device);
     let dtype = if args.use_f32 { DType::F32 } else { DType::F16 };

candle-examples/examples/musicgen/main.rs

@@ -16,7 +16,7 @@ use musicgen_model::{GenConfig, MusicgenForConditionalGeneration};
 use nn::VarBuilder;
 
 use anyhow::{Error as E, Result};
-use candle::{DType, Device};
+use candle::DType;
 use clap::Parser;
 
 const DTYPE: DType = DType::F32;
@@ -41,20 +41,7 @@ fn main() -> Result<()> {
     use tokenizers::Tokenizer;
 
     let args = Args::parse();
-    #[cfg(feature = "cuda")]
-    let default_device = Device::new_cuda(0)?;
-
-    #[cfg(not(feature = "cuda"))]
-    let default_device = {
-        println!("Running on CPU, to run on GPU, run this example with `--features cuda`");
-        Device::Cpu
-    };
-    let device = if args.cpu {
-        Device::Cpu
-    } else {
-        default_device
-    };
-
+    let device = candle_examples::device(args.cpu)?;
     let mut tokenizer = Tokenizer::from_file(args.tokenizer).map_err(E::msg)?;
     let _tokenizer = tokenizer.with_padding(None).with_truncation(None);
 

candle-examples/examples/whisper/main.rs

@@ -257,21 +257,7 @@ struct Args {
 
 fn main() -> Result<()> {
     let args = Args::parse();
-
-    #[cfg(feature = "cuda")]
-    let default_device = Device::new_cuda(0)?;
-
-    #[cfg(not(feature = "cuda"))]
-    let default_device = {
-        println!("Running on CPU, to run on GPU, run this example with `--features cuda`");
-        Device::Cpu
-    };
-
-    let device = if args.cpu {
-        Device::Cpu
-    } else {
-        default_device
-    };
+    let device = candle_examples::device(args.cpu)?;
     let default_model = "openai/whisper-tiny.en".to_string();
     let path = std::path::PathBuf::from(default_model.clone());
     let default_revision = "refs/pr/15".to_string();

candle-examples/src/lib.rs

@@ -1 +1,13 @@
+use candle::{Device, Result};
 
+pub fn device(cpu: bool) -> Result<Device> {
+    if cpu {
+        Ok(Device::Cpu)
+    } else {
+        let device = Device::cuda_if_available(0)?;
+        if !device.is_cuda() {
+            println!("Running on CPU, to run on GPU, build this example with `--features cuda`");
+        }
+        Ok(device)
+    }
+}