[SW] Add kernels: gemv, spmv, conjugate gradient

CHANGELOG.md

@@ -16,6 +16,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
  - Plot kernels-Vl performance plot
  - Print I$/D$ stall metrics
+ - Add `spmv`, `conjugate_gradient`, and `gemv` kernels.
 
 ### Changed
 

DEPENDENCIES.md

@@ -30,6 +30,8 @@ This file is licensed under the MIT license.
 
 `jacobi2d` comes from an adaptation of the software in `https://github.com/RALC88/riscv-vectorized-benchmark-suite`. The source file `apps/jacobi2d/main.c` contains the original licence.
 
+`conjugate_gradient` needs python package `sklearn` for generating symmetric and positivie-defined matrix
+
 ### Verilator simulations
 
 In order to run Verilator simulations, you will need a modern Verilator installation.

apps/common/default_args.mk

@@ -29,3 +29,7 @@ def_args_softmax     ?= "3 256"
 def_args_pathfinder  ?= "1 1024 64"
 # Batch_size, depth, height, width, n_boxes (in total), crop_h, crop_w
 def_args_roi_align   ?= "1 32 4 4 4 2 2"
+# SpMV configuration: row, col, density
+def_args_spmv        ?= "128 128 0.6"
+# Conjugate gradient size and steps
+def_args_conjugate_gradient	?= "128 0 0.5"

apps/conjugate_gradient/main.c

@@ -0,0 +1,200 @@
+// Copyright 2022 ETH Zurich and University of Bologna.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Author: Chi Zhang, ETH Zurich <[email protected]>
+
+#include <stdint.h>
+#include <string.h>
+
+#include "runtime.h"
+#include "shared_kernel/fdotproduct.h"
+#include "shared_kernel/gemv.h"
+#include "shared_kernel/spmv.h"
+#include "util.h"
+
+#ifndef SPIKE
+#include "printf.h"
+#else
+#include <stdio.h>
+#endif
+
+#define USE_SPMV 1
+#define MIN_LOSS 0.0005
+#define abs(x) (x < 0 ? -x : x)
+
+extern uint64_t size;
+extern uint64_t step;
+extern double sparsity;
+
+extern double A[] __attribute__((aligned(4 * NR_LANES), section(".l2")));
+extern double Ax[] __attribute__((aligned(4 * NR_LANES), section(".l2")));
+extern double x[] __attribute__((aligned(4 * NR_LANES), section(".l2")));
+extern double b[] __attribute__((aligned(4 * NR_LANES), section(".l2")));
+extern double r[] __attribute__((aligned(4 * NR_LANES), section(".l2")));
+extern double p[] __attribute__((aligned(4 * NR_LANES), section(".l2")));
+extern double Ap[] __attribute__((aligned(4 * NR_LANES), section(".l2")));
+extern int32_t A_PROW[] __attribute__((aligned(4 * NR_LANES), section(".l2")));
+extern int32_t A_IDX[] __attribute__((aligned(4 * NR_LANES), section(".l2")));
+extern double A_DATA[] __attribute__((aligned(4 * NR_LANES), section(".l2")));
+
+void daxpy(double *x, double a, double *y, double *dest, uint64_t len) {
+#define MAX_AVL 128
+  while (len > MAX_AVL) {
+    asm volatile("vsetvli zero, %0, e64, m2, ta, ma" ::"r"(MAX_AVL));
+    asm volatile("vle64.v v0, (%0);" ::"r"(x));
+    asm volatile("vle64.v v4, (%0);" ::"r"(y));
+    asm volatile("vfmacc.vf v4, %0, v0" ::"f"(a));
+    asm volatile("vse64.v v4, (%0);" ::"r"(dest));
+    x = x + MAX_AVL;
+    y = y + MAX_AVL;
+    dest = dest + MAX_AVL;
+    len = len - MAX_AVL;
+  }
+  if (len > 0) {
+    asm volatile("vsetvli zero, %0, e64, m2, ta, ma" ::"r"(len));
+    asm volatile("vle64.v v0, (%0);" ::"r"(x));
+    asm volatile("vle64.v v4, (%0);" ::"r"(y));
+    asm volatile("vfmacc.vf v4, %0, v0" ::"f"(a));
+    asm volatile("vse64.v v4, (%0);" ::"r"(dest));
+  }
+}
+
+double CG_iteration_gemv(double *A, double *x, double *b, double *r, double *p,
+                         double *Ap, uint64_t size) {
+  /*
+  Calculate step length alpha
+  */
+  double rk_norm = fdotp_v64b(r, r, size);
+  gemv_rowwise(size, size, A, p, Ap);
+  double pAp = fdotp_v64b(p, Ap, size);
+  double alpha = rk_norm / pAp;
+
+  /*
+  update x
+  */
+  daxpy(p, alpha, x, x, size);
+
+  /*
+  update loss r
+  */
+  daxpy(Ap, (-1.0) * alpha, r, r, size);
+
+  /*
+  calculate beta
+  */
+  double rk_norm_new = fdotp_v64b(r, r, size);
+  double beta = rk_norm_new / rk_norm;
+  /*
+  update p
+  */
+  daxpy(p, beta, r, p, size);
+
+  /*
+  return loss
+  */
+  return rk_norm_new;
+}
+
+double CG_iteration_spmv(int32_t *A_PROW, int32_t *A_IDX, double *A_DATA,
+                         double *x, double *b, double *r, double *p, double *Ap,
+                         uint64_t size) {
+  /*
+  Calculate step length alpha
+  */
+  double rk_norm = fdotp_v64b(r, r, size);
+  spmv_csr_idx32(size, A_PROW, A_IDX, A_DATA, p, Ap);
+  double pAp = fdotp_v64b(p, Ap, size);
+  // printf("pAp: %f\n", pAp);
+  if (abs(pAp) < MIN_LOSS) {
+    return rk_norm;
+  }
+  double alpha = rk_norm / pAp;
+
+  /*
+  update x
+  */
+  daxpy(p, alpha, x, x, size);
+
+  /*
+  update loss r
+  */
+  daxpy(Ap, (-1.0) * alpha, r, r, size);
+
+  /*
+  calculate beta
+  */
+  double rk_norm_new = fdotp_v64b(r, r, size);
+  double beta = rk_norm_new / rk_norm;
+
+  /*
+  update p
+  */
+  daxpy(p, beta, r, p, size);
+
+  /*
+  return loss
+  */
+  return rk_norm_new;
+}
+
+int main() {
+  printf("\n");
+  printf("========================\n");
+  printf("=  Conjugate Gradient  =\n");
+  printf("========================\n");
+  printf("\n");
+  printf("\n");
+
+  printf("\n");
+  printf("------------------------------------------------------------\n");
+  printf("Solving a Ax=b equation with (%d x %d) Matrix size...\n", size, size);
+  if (USE_SPMV) {
+    printf("Sparse Matrix in CSR format, with %f nonzeros per row\n",
+           sparsity * size);
+  }
+  printf("------------------------------------------------------------\n");
+  printf("\n");
+
+  printf("Initializing CGM parameters...\n");
+  if (USE_SPMV) {
+    spmv_csr_idx32(size, A_PROW, A_IDX, A_DATA, x, Ax);
+  } else {
+    gemv_rowwise(size, size, A, x, Ax);
+  }
+  daxpy(Ax, -1.0, b, r, size);
+  daxpy(Ax, -1.0, b, p, size);
+
+  printf("Start CGM ...\n");
+  uint64_t i = 0;
+  while (1) {
+    if (step > 0 && i >= step) {
+      break;
+    }
+
+    double loss;
+    if (USE_SPMV) {
+      loss = CG_iteration_spmv(A_PROW, A_IDX, A_DATA, x, b, r, p, Ap, size);
+    } else {
+      loss = CG_iteration_gemv(A, x, b, r, p, Ap, size);
+    }
+    printf("iteration %d, loss: %f\n", i, loss);
+    if (loss < MIN_LOSS) {
+      break;
+    }
+    i++;
+  }
+  return 0;
+}