seemingly working fp32 implementation

hw/dpi/float_dpi.cpp

@@ -23,6 +23,9 @@
 #include "verilated_vpi.h"
 #include "VX_config.h"
 
+#include <bit>
+#include "half.hpp"
+
 extern "C" {
   void dpi_fadd(bool enable, int dst_fmt, int64_t a, int64_t b, const svBitVecVal* frm, int64_t* result, svBitVecVal* fflags);
   void dpi_fsub(bool enable, int dst_fmt, int64_t a, int64_t b, const svBitVecVal* frm, int64_t* result, svBitVecVal* fflags);
@@ -51,6 +54,8 @@ extern "C" {
   void dpi_feq(bool enable, int dst_fmt, int64_t a, int64_t b, int64_t* result, svBitVecVal* fflags);
   void dpi_fmin(bool enable, int dst_fmt, int64_t a, int64_t b, int64_t* result, svBitVecVal* fflags);
   void dpi_fmax(bool enable, int dst_fmt, int64_t a, int64_t b, int64_t* result, svBitVecVal* fflags);
+
+  void dpi_hmma(bool enable, const svBitVecVal* A_tile, const svBitVecVal* B_tile, const svBitVecVal* C_tile, svBitVecVal* D_tile);
 }
 
 inline uint64_t nan_box(uint32_t value) {
@@ -338,3 +343,74 @@ void dpi_fmax(bool enable, int dst_fmt, int64_t a, int64_t b, int64_t* result, s
     *result = nan_box(rv_fmax_s(check_boxing(a), check_boxing(b), fflags));
   }
 }
+
+// A is M * K, B is K * K * M, C is M * M, D is M * M
+#define M 4
+#define K 2
+
+// all row major
+float c_A_tile[M][K];
+float c_B_tile[K][M];
+float c_C_tile[M][M];
+float c_D_tile[M][M];
+
+// code assumes that svBitVecVal is basically a uint32_t
+static_assert(sizeof(svBitVecVal) == 4);
+
+void fill_float_array(const svBitVecVal* sv_tile, float* c_tile, int rows, int cols) {
+  
+  for (int i = 0; i < rows; i += 1) {
+    for (int j = 0; j < cols; j += 1) {
+      int index = i * cols + j;
+      svBitVecVal sv_val = sv_tile[index];
+
+      uint32_t c_val = sv_val;
+      float c_float;
+
+      memcpy(&c_float, &c_val, sizeof(c_float));
+      c_tile[index] = c_float;
+      
+      // std::cout << c_float << " ";
+    }
+    // std::cout << std::endl;
+  }
+}
+
+void write_float_array(svBitVecVal* sv_tile, float* c_tile, int rows, int cols) {
+  for (int i = 0; i < rows; i += 1) {
+    for (int j = 0; j < cols; j += 1) {
+      int index = i * cols + j;
+      svBitVecVal* sv_val = &sv_tile[index];
+
+      float c_float = c_tile[index];
+      memcpy(sv_val, &c_float, sizeof(c_float));
+
+      // std::cout << c_float << " ";
+    }
+    // std::cout << std::endl;
+  }
+}
+
+void dpi_hmma(bool enable, const svBitVecVal* A_tile, const svBitVecVal* B_tile, const svBitVecVal* C_tile, svBitVecVal* D_tile) {
+  if (!enable) {
+    return;
+  }
+  // std::cout << "A: " << std::endl;
+  fill_float_array(A_tile, &c_A_tile[0][0], M, K);
+  // std::cout << "B: " << std::endl;
+  fill_float_array(B_tile, &c_B_tile[0][0], K, M);
+  // std::cout << "C: " << std::endl;
+  fill_float_array(C_tile, &c_C_tile[0][0], M, M);
+  
+  for (int i = 0; i < M; i += 1) {
+    for (int j = 0; j < M; j += 1) {
+      float accum = c_C_tile[i][j];
+      for (int k = 0; k < K; k += 1) {
+        accum += c_A_tile[i][k] * c_B_tile[k][j];
+      }
+      c_D_tile[i][j] = accum;
+    }
+  }
+
+  write_float_array(D_tile, &c_D_tile[0][0], M, M);
+}

hw/dpi/float_dpi.vh

@@ -44,4 +44,6 @@ import "DPI-C" function void dpi_feq(input logic enable, input int dst_fmt, inpu
 import "DPI-C" function void dpi_fmin(input logic enable, input int dst_fmt, input longint a, input longint b, output longint result, output bit[4:0] fflags);
 import "DPI-C" function void dpi_fmax(input logic enable, input int dst_fmt, input longint a, input longint b, output longint result, output bit[4:0] fflags);
 
+import "DPI-C" function void dpi_hmma(input logic enable, input bit[3:0][1:0][31:0] A_tile, input bit[1:0][3:0][31:0] B_tile, input bit[3:0][3:0][31:0] C_tile, output bit[3:0][3:0][31:0] D_tile);
+
 `endif

hw/rtl/VX_config.vh

@@ -385,6 +385,11 @@
 `define LATENCY_FCVT 5
 `endif
 
+// Tensor Core Latency
+`ifndef LATENCY_HMMA
+`define LATENCY_HMMA 4
+`endif
+
 // Icache Configurable Knobs //////////////////////////////////////////////////
 
 // Cache Enable

hw/rtl/fpu/VX_tensor_dpu.sv

@@ -0,0 +1,35 @@
+`include "VX_fpu_define.vh"
+
+module VX_tensor_dpu #(
+
+) (
+    input clk,
+    input reset,
+
+    input valid_in,
+    input [3:0][1:0][31:0] A_tile,
+    input [1:0][3:0][31:0] B_tile,
+    input [3:0][3:0][31:0] C_tile,
+
+    output valid_out,
+    output [3:0][3:0][31:0] D_tile
+);
+    logic [3:0][3:0][31:0] result_hmma;
+
+    always @(*) begin
+        dpi_hmma(valid_in, A_tile, B_tile, C_tile, result_hmma);
+    end
+    
+
+    VX_shift_register #(
+        .DATAW  (1 + $bits(D_tile)),
+        .DEPTH  (`LATENCY_HMMA),
+        .RESETW (1)
+    ) shift_reg (
+        .clk      (clk),
+        .reset    (reset),
+        .enable   (1'b1),
+        .data_in  ({valid_in, result_hmma}),
+        .data_out ({valid_out, D_tile})
+    );
+endmodule

hw/rtl/fpu/VX_tensor_tb.sv

@@ -0,0 +1,28 @@
+`include "VX_fpu_define.vh"
+
+module VX_tensor_tb(
+    input clk,
+    input reset,
+
+    input valid_in,
+    input [3:0][1:0][31:0] A_tile,
+    input [1:0][3:0][31:0] B_tile,
+    input [3:0][3:0][31:0] C_tile,
+
+    output valid_out,
+    output [3:0][3:0][31:0] D_tile
+);
+
+    VX_tensor_dpu #() tensor_core (
+        .clk(clk),
+        .reset(reset),
+
+        .valid_in(valid_in),
+        .A_tile(A_tile),
+        .B_tile(B_tile),
+        .C_tile(C_tile),
+
+        .valid_out(valid_out),
+        .D_tile(D_tile)
+    );
+endmodule

hw/unittest/tensor/Makefile

@@ -0,0 +1,89 @@
+DESTDIR ?= .
+RTL_DIR = ../../rtl
+DPI_DIR = $(abspath ../../dpi)
+SIM_DIR = ../../../sim
+THIRD_PARTY_DIR = $(abspath ../../../third_party)
+
+CONFIGS +=
+PARAMS +=
+
+CXXFLAGS += -std=c++17 -Wall -Wextra -Wfatal-errors -Wno-array-bounds
+CXXFLAGS += -fPIC -Wno-maybe-uninitialized
+CXXFLAGS += -fcoroutines
+CXXFLAGS += -I../../.. -I../../common -I../../../../sim/common
+CXXFLAGS += -I/$(THIRD_PARTY_DIR)/softfloat/source/include
+CXXFLAGS += -I/$(DPI_DIR)
+CXXFLAGS += $(CONFIGS)
+
+LDFLAGS += $(THIRD_PARTY_DIR)/softfloat/build/Linux-x86_64-GCC/softfloat.a
+
+# control RTL debug tracing states
+DBG_TRACE_FLAGS += -DDBG_TRACE_CACHE_BANK 
+DBG_TRACE_FLAGS += -DDBG_TRACE_CACHE_MSHR
+DBG_TRACE_FLAGS += -DDBG_TRACE_CACHE_TAG
+DBG_TRACE_FLAGS += -DDBG_TRACE_CACHE_DATA
+
+DBG_FLAGS += -DDEBUG_LEVEL=$(DEBUG) -DVCD_OUTPUT $(DBG_TRACE_FLAGS)
+
+RTL_PKGS = $(RTL_DIR)/VX_gpu_pkg.sv
+
+RTL_INCLUDE = -I$(RTL_DIR) -I$(DPI_DIR) -I$(RTL_DIR)/libs -I$(RTL_DIR)/fpu
+
+# SRCS = cachesim.cpp testbench.cpp
+SRCS += $(DPI_DIR)/util_dpi.cpp
+SRCS += $(DPI_DIR)/float_dpi.cpp
+SRCS += $(SIM_DIR)/common/rvfloats.cpp
+SRCS += ./main.cpp
+
+RTL_SRCS += $(RTL_DIR)/fpu/VX_tensor_core.sv
+RTL_SRCS += $(RTL_DIR)/fpu/VX_tensor_tb.sv
+
+TOP = VX_tensor_tb
+
+VL_FLAGS = --exe
+VL_FLAGS += --language 1800-2009 # -Wall -Wpedantic # --assert 
+VL_FLAGS += -Wno-DECLFILENAME -Wno-REDEFMACRO
+VL_FLAGS += --x-initial unique --x-assign unique
+VL_FLAGS += -DSIMULATION -DSV_DPI
+VL_FLAGS += $(CONFIGS)
+VL_FLAGS += $(PARAMS)
+VL_FLAGS += $(RTL_INCLUDE)
+VL_FLAGS += $(RTL_PKGS)
+VL_FLAGS += --cc $(TOP) --top-module $(TOP)
+VL_FLAGS += --timing
+
+# Enable Verilator multithreaded simulation
+THREADS ?= $(shell python -c 'import multiprocessing as mp; print(mp.cpu_count())')
+VL_FLAGS += -j $(THREADS)
+#VL_FLAGS += --threads $(THREADS)
+
+# Debugigng
+ifdef DEBUG
+	VL_FLAGS += --trace --trace-structs $(DBG_FLAGS)
+	CXXFLAGS += -g -O0 $(DBG_FLAGS)
+else    
+	VL_FLAGS += -DNDEBUG
+	CXXFLAGS += -O2 -DNDEBUG
+endif
+
+# Enable perf counters
+ifdef PERF
+	VL_FLAGS += -DPERF_ENABLE
+	CXXFLAGS += -DPERF_ENABLE
+endif
+
+PROJECT = tensor
+
+all: $(DESTDIR)/$(PROJECT)
+	
+$(DESTDIR)/$(PROJECT): $(SRCS) $(RTL_SRCS)
+	verilator --build $(VL_FLAGS) $(SRCS) -CFLAGS '$(CXXFLAGS)' -LDFLAGS '$(LDFLAGS)' -o ../$@
+
+run: $(DESTDIR)/$(PROJECT)
+	$(DESTDIR)/$(PROJECT)
+
+waves: trace.vcd
+	gtkwave -o trace.vcd
+
+clean:
+	rm -rf obj_dir $(DESTDIR)/$(PROJECT)

hw/unittest/tensor/main.cpp

@@ -0,0 +1,197 @@
+// Copyright © 2019-2023
+// 
+// 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.
+
+#include "vl_simulator.h"
+#include "VVX_tensor_tb.h"
+#include <iostream>
+
+#include <half.hpp>
+
+#define MAX_TICKS 20
+
+#ifndef TRACE_START_TIME
+#define TRACE_START_TIME 0ull
+#endif
+
+#ifndef TRACE_STOP_TIME
+#define TRACE_STOP_TIME -1ull
+#endif
+
+#define CHECK(x)                                  \
+   do {                                           \
+     if (x)                                       \
+       break;                                     \
+     std::cout << "FAILED: " << #x << std::endl;  \
+	   std::abort();			                          \
+   } while (false)
+
+static uint64_t timestamp = 0;
+static bool trace_enabled = false;
+static uint64_t trace_start_time = TRACE_START_TIME;
+static uint64_t trace_stop_time  = TRACE_STOP_TIME;
+
+double sc_time_stamp() { 
+  return timestamp;
+}
+
+bool sim_trace_enabled() {
+  if (timestamp >= trace_start_time 
+   && timestamp < trace_stop_time)
+    return true;
+  return trace_enabled;
+}
+
+void sim_trace_enable(bool enable) {
+  trace_enabled = enable;
+}
+
+using Device = VVX_tensor_tb;
+using half_float::half;
+
+static_assert(sizeof(half) == 2);
+uint32_t half2bits(half h) {
+    uint16_t half_bits;
+    memcpy(&half_bits, &h, sizeof(half));
+    return half_bits;
+}
+
+uint32_t float2bits(float f) {
+  uint32_t float_bits;
+  memcpy(&float_bits, &f, sizeof(f));
+  return float_bits;
+}
+
+float bits2float(uint32_t b) {
+  float f;
+  memcpy(&f, &b, sizeof(b));
+  return f;
+}
+
+// A is M * K, B is K * K * M, C is M * M, D is M * M
+#define M 4
+#define K 2
+
+// row, column
+float A_tile[M][K];
+float B_tile[K][M];
+float C_tile[M][M];
+float D_tile[M][M];
+
+void initialize_test_data() {
+  for (int i = 0; i < M; i += 1) {
+    for (int j = 0; j < K; j += 1) {
+      A_tile[i][j] = (float) (i * K + j);
+    }
+  }
+
+  for (int i = 0; i < K; i += 1) {
+    for (int j = 0; j < M; j += 1) {
+      B_tile[i][j] = (float) (j * K + i);
+    }
+  }
+  for (int i = 0; i < M; i += 1) {
+    for (int j = 0; j < M; j += 1) {
+      C_tile[i][j] = (float) (i * j);
+    }
+  }
+}
+
+void write_test_data(vl_simulator<Device>& sim) {
+  for (int i = 0; i < M; i += 1) {
+    for (int j = 0; j < K; j += 1) {
+      int index = (i * K + j);
+      uint32_t A_bits = float2bits(A_tile[i][j]);
+      sim->A_tile[index] = A_bits;
+    }
+  }
+
+  for (int i = 0; i < K; i += 1) {
+    for (int j = 0; j < M; j += 1) {
+      int index = (i * M + j);
+      uint32_t B_bits = float2bits(B_tile[i][j]);
+      sim->B_tile[index] = B_bits;
+    }
+  }
+
+  for (int i = 0; i < M; i += 1) {
+    for (int j = 0; j < M; j += 1) {
+      int index = (i * M + j);
+      uint32_t C_bits = float2bits(C_tile[i][j]);
+      sim->C_tile[index] = C_bits;
+    }
+  }
+}
+
+void read_result(vl_simulator<Device>& sim) {
+  for (int i = 0; i < M; i += 1) {
+    for (int j = 0; j < M; j += 1) {
+      int index = (i * M + j);
+
+      uint32_t D_bits = sim->D_tile[index];
+      float f = bits2float(D_bits);
+      D_tile[i][j] = f;
+      std::cout << f << " ";
+    }
+    std::cout << std::endl;
+  }
+}
+
+void expected() {
+  for (int i = 0; i < M; i += 1) {
+    for (int j = 0; j < M; j += 1) {
+      float accum = C_tile[i][j];
+      for (int k = 0; k < K; k += 1) {
+        accum += A_tile[i][k] * B_tile[k][j];
+      }
+
+      std::cout << accum << " ";
+    }
+    std::cout << std::endl;
+  }
+}
+
+int main(int argc, char **argv) {
+  // Initialize Verilators variables
+  Verilated::commandArgs(argc, argv);
+
+  vl_simulator<Device> sim;
+
+  initialize_test_data();
+  // run test
+  timestamp = sim.reset(0);
+
+
+  // advance clock
+  timestamp = sim.step(timestamp, 10);
+  sim->valid_in = 1;
+  write_test_data(sim);
+  timestamp = sim.step(timestamp, 2);
+  CHECK(sim->valid_out == 0);
+  sim->valid_in = 0;
+  timestamp = sim.step(timestamp, 2);
+  CHECK(sim->valid_out == 0);
+  timestamp = sim.step(timestamp, 2);
+  CHECK(sim->valid_out == 0);
+  timestamp = sim.step(timestamp, 2);
+  CHECK(sim->valid_out == 1);
+  read_result(sim);
+  timestamp = sim.step(timestamp, 2);
+  CHECK(sim->valid_out == 0);
+
+  expected();
+
+  std::cout << "PASSED!" << std::endl;
+  std::cout << "Simulation time: " << std::dec << timestamp/2 << " cycles" << std::endl;
+
+  return 0;
+}