-- wip --

Cargo.toml

@@ -21,16 +21,17 @@ include = [
 default = []
 # Compile in portable mode, without ISA extensions.
 # Binary can be executed on all systems.
-portable = [ "semolina/portable" ]
+portable = ["semolina/portable"]
 # Enable ADX even if the host CPU doesn't support it.
 # Binary can be executed on Broadwell+ and Ryzen+ systems.
-force-adx = [ "semolina/force-adx" ]
+force-adx = ["semolina/force-adx"]
 cuda-mobile = []
 
 [dependencies]
 semolina = "~0.1.3"
-sppark = "~0.1.2"
-pasta_curves = { git="https://github.com/lurk-lab/pasta_curves", branch="dev", version = ">=0.3.1, <=0.5", features = ["repr-c"] }
+sppark = { git = "https://github.com/lurk-lab/sppark.git", branch = "preallocated-msm" }
+pasta_curves = { git = "https://github.com/lurk-lab/pasta_curves", branch = "dev", version = ">=0.3.1, <=0.5", features = ["repr-c"] }
+paste = "1.0.14"
 
 [build-dependencies]
 cc = "^1.0.70"

benches/main.rs

@@ -66,6 +66,17 @@ fn criterion_benchmark(c: &mut Criterion) {
             })
         });
 
+        let context = pasta_msm::pallas_init(&points, npoints);
+
+        group.bench_function(
+            format!("preallocated 2**{} points", bench_npow),
+            |b| {
+                b.iter(|| {
+                    let _ = pasta_msm::pallas_with(&context, npoints, &scalars);
+                })
+            },
+        );
+
         group.finish();
     }
 }

cuda/pallas.cu

@@ -17,8 +17,35 @@ typedef vesta_t scalar_t;
 #include <msm/pippenger.cuh>
 
 #ifndef __CUDA_ARCH__
-extern "C"
-RustError cuda_pippenger_pallas(point_t *out, const affine_t points[], size_t npoints,
-                                              const scalar_t scalars[])
-{   return mult_pippenger<bucket_t>(out, points, npoints, scalars);   }
+
+template <typename T>
+struct msm_context_t
+{
+    T *d_points;
+};
+
+extern "C" void drop_msm_context_t(msm_context_t<void> &ref)
+{
+    CUDA_OK(cudaFree(ref.d_points));
+}
+
+extern "C" RustError
+cuda_pippenger_pallas_init(const affine_t points[], size_t npoints, msm_context_t<affine_t::mem_t> *msm_context)
+{
+    msm_t<bucket_t, point_t, affine_t, scalar_t> msm{points, npoints, false};
+    msm_context->d_points = msm.get_d_points();
+    return RustError{cudaSuccess};
+}
+
+extern "C" RustError cuda_pippenger_pallas(point_t *out, const affine_t points[], size_t npoints,
+                                           const scalar_t scalars[])
+{
+    return mult_pippenger<bucket_t>(out, points, npoints, scalars);
+}
+
+extern "C" RustError cuda_pippenger_pallas_with(point_t *out, msm_context_t<affine_t::mem_t> *msm_context, size_t npoints,
+                                                       const scalar_t scalars[])
+{
+    return mult_pippenger_with<bucket_t, point_t, affine_t, scalar_t>(out, msm_context->d_points, npoints, scalars);
+}
 #endif

cuda/vesta.cu

@@ -17,8 +17,35 @@ typedef pallas_t scalar_t;
 #include <msm/pippenger.cuh>
 
 #ifndef __CUDA_ARCH__
-extern "C"
-RustError cuda_pippenger_vesta(point_t *out, const affine_t points[], size_t npoints,
-                                              const scalar_t scalars[])
-{   return mult_pippenger<bucket_t>(out, points, npoints, scalars);   }
+
+template <typename T>
+struct msm_context_t
+{
+    T *d_points;
+};
+
+extern "C" void drop_msm_context_t(msm_context_t<void> &ref)
+{
+    CUDA_OK(cudaFree(ref.d_points));
+}
+
+extern "C" RustError
+cuda_pippenger_vesta_init(const affine_t points[], size_t npoints, msm_context_t<affine_t::mem_t> *msm_context)
+{
+    msm_t<bucket_t, point_t, affine_t, scalar_t> msm{points, npoints, false};
+    msm_context->d_points = msm.get_d_points();
+    return RustError{cudaSuccess};
+}
+
+extern "C" RustError cuda_pippenger_vesta(point_t *out, const affine_t points[], size_t npoints,
+                                          const scalar_t scalars[])
+{
+    return mult_pippenger<bucket_t>(out, points, npoints, scalars);
+}
+
+extern "C" RustError cuda_pippenger_vesta_with(point_t *out, msm_context_t<affine_t::mem_t> *msm_context, size_t npoints,
+                                                const scalar_t scalars[])
+{
+    return mult_pippenger_with<bucket_t, point_t, affine_t, scalar_t>(out, msm_context->d_points, npoints, scalars);
+}
 #endif

src/lib.rs

@@ -4,6 +4,45 @@
 
 extern crate semolina;
 
+#[cfg(feature = "cuda")]
+#[repr(C)]
+#[derive(Debug)]
+pub struct MSMContext {
+    context: *const std::ffi::c_void,
+}
+
+#[cfg(feature = "cuda")]
+unsafe impl Send for MSMContext {}
+
+#[cfg(feature = "cuda")]
+unsafe impl Sync for MSMContext {}
+
+#[cfg(feature = "cuda")]
+impl Default for MSMContext {
+    fn default() -> Self {
+        Self { context: std::ptr::null() }
+    }
+}
+
+#[cfg(feature = "cuda")]
+impl Clone for MSMContext {
+    fn clone(&self) -> Self {
+        Self { context: self.context.clone() }
+    }
+}
+
+#[cfg(feature = "cuda")]
+// TODO: check for device-side memory leaks
+impl Drop for MSMContext {
+    fn drop(&mut self) {
+        extern "C" {
+            fn drop_msm_context_t(by_ref: &MSMContext);
+        }
+        unsafe { drop_msm_context_t(std::mem::transmute::<&_, &_>(self)) };
+        self.context = core::ptr::null();
+    }
+}
+
 #[cfg(feature = "cuda")]
 sppark::cuda_error!();
 #[cfg(feature = "cuda")]
@@ -31,6 +70,79 @@ macro_rules! multi_scalar_mult {
             );
         }
 
+        paste::paste! {
+            #[cfg(feature = "cuda")]
+            pub fn [<$pasta _init>](
+                points: &[$pasta::Affine],
+                npoints: usize,
+            ) -> MSMContext {
+                unsafe { assert!(!CUDA_OFF && cuda_available(), "feature = \"cuda\" must be enabled") };
+                if npoints != points.len() && npoints < 1 << 16 {
+                    panic!("length mismatch or less than 10**16")
+                }
+                extern "C" {
+                    fn [<cuda_pippenger_ $pasta _init>](
+                        points: *const pallas::Affine,
+                        npoints: usize,
+                        d_points: &mut MSMContext,
+                        is_mont: bool,
+                    ) -> cuda::Error;
+
+                }
+
+                let mut ret = MSMContext::default();
+                let err = unsafe {
+                    [<cuda_pippenger_ $pasta _init>](
+                        points.as_ptr() as *const _,
+                        npoints,
+                        &mut ret,
+                        true,
+                    )
+                };
+                if err.code != 0 {
+                    panic!("{}", String::from(err));
+                }
+                ret
+            }
+
+            #[cfg(feature = "cuda")]
+            pub fn [<$pasta _with>](
+                context: &MSMContext,
+                npoints: usize,
+                scalars: &[$pasta::Scalar],
+            ) -> $pasta::Point {
+                unsafe { assert!(!CUDA_OFF && cuda_available(), "feature = \"cuda\" must be enabled") };
+                if npoints != scalars.len() && npoints < 1 << 16 {
+                    panic!("length mismatch or less than 10**16")
+                }
+                extern "C" {
+                    fn [<cuda_pippenger_ $pasta _with>](
+                        out: *mut $pasta::Point,
+                        context: &MSMContext,
+                        npoints: usize,
+                        scalars: *const $pasta::Scalar,
+                        is_mont: bool,
+                    ) -> cuda::Error;
+
+                }
+
+                let mut ret = $pasta::Point::default();
+                let err = unsafe {
+                    [<cuda_pippenger_ $pasta _with>](
+                        &mut ret,
+                        context,
+                        npoints,
+                        &scalars[0],
+                        true,
+                    )
+                };
+                if err.code != 0 {
+                    panic!("{}", String::from(err));
+                }
+                ret
+            }
+        }
+
         pub fn $pasta(
             points: &[$pasta::Affine],
             scalars: &[$pasta::Scalar],