From e0980bbcd94aaa4c020236411c6483173a599193 Mon Sep 17 00:00:00 2001
From: David Harris <David_Harris@hmc.edu>
Date: Thu, 6 Feb 2025 18:20:07 -0800
Subject: [PATCH] Initial FMA commit

---
 examples/exercises/fma16/fma.do          | 23 +++++++++++
 examples/exercises/fma16/lint-fma        | 13 ++++++
 examples/exercises/fma16/sim-fma         |  2 +
 examples/exercises/fma16/sim-fma-batch   |  1 +
 examples/exercises/fma16/testbench.sv    | 52 ++++++++++++++++++++++++
 examples/exercises/fma16/tests/fmul_0.tv |  5 +++
 6 files changed, 96 insertions(+)
 create mode 100644 examples/exercises/fma16/fma.do
 create mode 100755 examples/exercises/fma16/lint-fma
 create mode 100755 examples/exercises/fma16/sim-fma
 create mode 100755 examples/exercises/fma16/sim-fma-batch
 create mode 100644 examples/exercises/fma16/testbench.sv
 create mode 100644 examples/exercises/fma16/tests/fmul_0.tv

diff --git a/examples/exercises/fma16/fma.do b/examples/exercises/fma16/fma.do
new file mode 100644
index 000000000..111b393ca
--- /dev/null
+++ b/examples/exercises/fma16/fma.do
@@ -0,0 +1,23 @@
+# fma.do 
+#
+# run with vsim -do "do fma.do"
+# add -c before -do for batch simulation
+
+onbreak {resume}
+
+# create library
+vlib worklib
+
+vlog -lint -sv -work worklib fma16.sv testbench.sv
+vopt +acc worklib.testbench_fma16 -work worklib -o testbenchopt
+vsim -lib worklib testbenchopt
+
+add wave sim:/testbench_fma16/clk
+add wave sim:/testbench_fma16/reset
+add wave sim:/testbench_fma16/x
+add wave sim:/testbench_fma16/y
+add wave sim:/testbench_fma16/z
+add wave sim:/testbench_fma16/result
+add wave sim:/testbench_fma16/rexpected
+
+run -all
diff --git a/examples/exercises/fma16/lint-fma b/examples/exercises/fma16/lint-fma
new file mode 100755
index 000000000..b577bbd33
--- /dev/null
+++ b/examples/exercises/fma16/lint-fma
@@ -0,0 +1,13 @@
+#!/bin/bash
+# check for warnings in Verilog code
+# The verilator lint tool is faster and better than Questa so it is best to run this first.
+export PATH=$PATH:/usr/local/bin/
+verilator=`which verilator`
+
+basepath=$(dirname $0)/..
+if ($verilator --lint-only --top-module fma16 fma16.sv); then
+    echo "fma16 passed lint"
+else
+    echo "fma16 failed lint"
+fi
+
diff --git a/examples/exercises/fma16/sim-fma b/examples/exercises/fma16/sim-fma
new file mode 100755
index 000000000..bf55614c5
--- /dev/null
+++ b/examples/exercises/fma16/sim-fma
@@ -0,0 +1,2 @@
+vsim -do "do fma.do"
+
diff --git a/examples/exercises/fma16/sim-fma-batch b/examples/exercises/fma16/sim-fma-batch
new file mode 100755
index 000000000..01c2472e9
--- /dev/null
+++ b/examples/exercises/fma16/sim-fma-batch
@@ -0,0 +1 @@
+vsim -c -do "do fma.do"
diff --git a/examples/exercises/fma16/testbench.sv b/examples/exercises/fma16/testbench.sv
new file mode 100644
index 000000000..ce4097abc
--- /dev/null
+++ b/examples/exercises/fma16/testbench.sv
@@ -0,0 +1,52 @@
+/* verilator lint_off STMTDLY */
+module testbench_fma16;
+  logic        clk, reset;
+  logic [15:0] x, y, z, rexpected, result;
+  logic [7:0]  ctrl;
+  logic        mul, add, negp, negz;
+  logic [1:0]  roundmode;
+  logic [31:0] vectornum, errors;
+  logic [75:0] testvectors[10000:0];
+  logic [3:0]  flags, flagsexpected; // Invalid, Overflow, Underflow, Inexact
+
+  // instantiate device under test
+  fma16 dut(x, y, z, mul, add, negp, negz, roundmode, result, flags);
+
+  // generate clock
+  always 
+    begin
+      clk = 1; #5; clk = 0; #5;
+    end
+
+  // at start of test, load vectors and pulse reset
+  initial
+    begin
+      $readmemh("tests/fmul_2.tv", testvectors);
+      vectornum = 0; errors = 0;
+      reset = 1; #22; reset = 0;
+    end
+
+  // apply test vectors on rising edge of clk
+  always @(posedge clk)
+    begin
+      #1; {x, y, z, ctrl, rexpected, flagsexpected} = testvectors[vectornum];
+      {roundmode, mul, add, negp, negz} = ctrl[5:0];
+    end
+
+  // check results on falling edge of clk
+  always @(negedge clk)
+    if (~reset) begin // skip during reset
+      if (result !== rexpected | flags !== flagsexpected) begin  // check result
+        $display("Error: inputs %h * %h + %h", x, y, z);
+        $display("  result = %h (%h expected) flags = %b (%b expected)", 
+          result, rexpected, flags, flagsexpected);
+        errors = errors + 1;
+      end
+      vectornum = vectornum + 1;
+      if (testvectors[vectornum] === 'x) begin 
+        $display("%d tests completed with %d errors", 
+	           vectornum, errors);
+        $stop;
+      end
+    end
+endmodule
diff --git a/examples/exercises/fma16/tests/fmul_0.tv b/examples/exercises/fma16/tests/fmul_0.tv
new file mode 100644
index 000000000..b139db2a3
--- /dev/null
+++ b/examples/exercises/fma16/tests/fmul_0.tv
@@ -0,0 +1,5 @@
+// Multiply with exponent of 0, significand of 1.0 and 1.1, RZ
+3c00_3c00_0000_08_3c00_0 // 1.000000 * 1.000000 = 1.000000 NV: 0 OF: 0 UF: 0 NX: 0
+3c00_3e00_0000_08_3e00_0 // 1.000000 * 1.500000 = 1.500000 NV: 0 OF: 0 UF: 0 NX: 0
+3e00_3c00_0000_08_3e00_0 // 1.500000 * 1.000000 = 1.500000 NV: 0 OF: 0 UF: 0 NX: 0
+3e00_3e00_0000_08_4080_0 // 1.500000 * 1.500000 = 2.250000 NV: 0 OF: 0 UF: 0 NX: 0