add relational operations to stack machine

7 files changed, 394 insertions, 4 deletions

diff --git a/design/stack_machine.v b/design/stack_machine.v
index b5c56e6..687168a 100644
--- a/design/stack_machine.v
+++ b/design/stack_machine.v
@@ -54,8 +54,13 @@ module stack_machine_new
 
    reg [31:0] 	      r0;
    reg [31:0] 	      r1;
-   reg [31:0] 	      im;
 
+   wire signed [31:0] r0s;
+   wire signed [31:0] r1s;
+   assign r0s = r0;
+   assign r1s = r1;
+
+   reg [31:0] 	      im;
    reg 		      im_initialized;
 
    parameter STEP_LOADING_INSTRUCTION = 1'b0;
@@ -243,6 +248,42 @@ module stack_machine_new
    assign instr_drop = !set_im && !use_im && stack_shrinks_by_1 &&
 		       instruction[11:0] == 12'd4;
 
+   wire 	      instr_eq;
+   assign instr_eq = !set_im && !use_im && stack_shrinks_by_1 &&
+		     instruction[11:0] == 12'd7;
+
+   wire 	      instr_lt;
+   assign instr_lt = !set_im && !use_im && stack_shrinks_by_1 &&
+		       instruction[11:0] == 12'd8;
+
+   wire 	      instr_ult;
+   assign instr_ult = !set_im && !use_im && stack_shrinks_by_1 &&
+		       instruction[11:0] == 12'd9;
+
+   wire 	      instr_le;
+   assign instr_le = !set_im && !use_im && stack_shrinks_by_1 &&
+		       instruction[11:0] == 12'd10;
+
+   wire 	      instr_ule;
+   assign instr_ule = !set_im && !use_im && stack_shrinks_by_1 &&
+		       instruction[11:0] == 12'd11;
+
+   wire 	      instr_gt;
+   assign instr_gt = !set_im && !use_im && stack_shrinks_by_1 &&
+		       instruction[11:0] == 12'd12;
+
+   wire 	      instr_ugt;
+   assign instr_ugt = !set_im && !use_im && stack_shrinks_by_1 &&
+		       instruction[11:0] == 12'd13;
+
+   wire 	      instr_ge;
+   assign instr_ge = !set_im && !use_im && stack_shrinks_by_1 &&
+		       instruction[11:0] == 12'd14;
+
+   wire 	      instr_uge;
+   assign instr_uge = !set_im && !use_im && stack_shrinks_by_1 &&
+		       instruction[11:0] == 12'd15;
+
    wire 	      instr_ret;
    assign instr_ret = !set_im && !use_im && stack_shrinks_by_1 &&
 		      instruction[11:0] == 12'b000010000000;
@@ -583,6 +624,33 @@ module stack_machine_new
 		   `SET_PC(im_effective);
 	      end
 
+	      if (instr_eq && arithmetic_uncompleted)
+		r1 <= r0 == r1;
+
+	      if (instr_lt && arithmetic_uncompleted)
+		r1 <= r0s < r1s;
+
+	      if (instr_ult && arithmetic_uncompleted)
+		r1 <= r0 < r1;
+
+	      if (instr_le && arithmetic_uncompleted)
+		r1 <= r0s <= r1s;
+
+	      if (instr_ule && arithmetic_uncompleted)
+		r1 <= r0 <= r1;
+
+	      if (instr_gt && arithmetic_uncompleted)
+		r1 <= r0s > r1s;
+
+	      if (instr_ugt && arithmetic_uncompleted)
+		r1 <= r0 > r1;
+
+	      if (instr_ge && arithmetic_uncompleted)
+		r1 <= r0s >= r1s;
+
+	      if (instr_uge && arithmetic_uncompleted)
+		r1 <= r0 >= r1;
+
 	      if (instr_ret && arithmetic_uncompleted) begin
 		 r1 <= r0;
 		 `SET_PC(r1);
diff --git a/tclasm.tcl b/tclasm.tcl
index 6a97b1f..90adda5 100755
--- a/tclasm.tcl
+++ b/tclasm.tcl
@@ -332,6 +332,51 @@ proc drop {} {
 }
 
 
+proc eq {} {
+    puts 0011000000000111
+}
+
+
+proc lt {} {
+    puts 0011000000001000
+}
+
+
+proc ult {} {
+    puts 0011000000001001
+}
+
+
+proc le {} {
+    puts 0011000000001010
+}
+
+
+proc ule {} {
+    puts 0011000000001011
+}
+
+
+proc gt {} {
+    puts 0011000000001100
+}
+
+
+proc ugt {} {
+    puts 0011000000001101
+}
+
+
+proc ge {} {
+    puts 0011000000001110
+}
+
+
+proc uge {} {
+    puts 0011000000001111
+}
+
+
 proc ret {} {
     puts 0011000010000000
 }
diff --git a/tests/stack_machine_relop/Makefile b/tests/stack_machine_relop/Makefile
new file mode 120000
index 0000000..2c3c770
--- /dev/null
+++ b/tests/stack_machine_relop/Makefile
@@ -0,0 +1 @@
+../stack_machine_store/Makefile
\ No newline at end of file
diff --git a/tests/stack_machine_relop/instructions.s.tcl b/tests/stack_machine_relop/instructions.s.tcl
new file mode 100644
index 0000000..5a83b53
--- /dev/null
+++ b/tests/stack_machine_relop/instructions.s.tcl
@@ -0,0 +1,235 @@
+### store 2 values to memory, load them back, add them and store the result
+
+set_sp 0
+
+## compare 1234567890 to itself
+
+const 1234567890
+const 1234567890
+# yields 1
+eq
+store h1EEE0
+
+const 1234567890
+const 1234567890
+# yields 0
+lt
+store h1EEE4
+
+const 1234567890
+const 1234567890
+# yields 0
+ult
+store h1EEE8
+
+const 1234567890
+const 1234567890
+# yields 1
+le
+store h1EEEC
+
+const 1234567890
+const 1234567890
+# yields 1
+ule
+store h1EEF0
+
+const 1234567890
+const 1234567890
+# yields 0
+gt
+store h1EEF4
+
+const 1234567890
+const 1234567890
+# yields 0
+ugt
+store h1EEF8
+
+const 1234567890
+const 1234567890
+# yields 1
+ge
+store h1EEFC
+
+const 1234567890
+const 1234567890
+# yields 1
+uge
+store h1EF00
+
+
+## compare hFFFFFFFF to h7FFFFFFF
+## hFFFFFFFF will be treated as negative for signed operations
+
+const hFFFFFFFF
+const h7FFFFFFF
+# yields 0
+eq
+store h1F0E0
+
+const hFFFFFFFF
+const h7FFFFFFF
+# yields 1
+lt
+store h1F0E4
+
+const hFFFFFFFF
+const h7FFFFFFF
+# yields 0
+ult
+store h1F0E8
+
+const hFFFFFFFF
+const h7FFFFFFF
+# yields 1
+le
+store h1F0EC
+
+const hFFFFFFFF
+const h7FFFFFFF
+# yields 0
+ule
+store h1F0F0
+
+const hFFFFFFFF
+const h7FFFFFFF
+# yields 0
+gt
+store h1F0F4
+
+const hFFFFFFFF
+const h7FFFFFFF
+# yields 1
+ugt
+store h1F0F8
+
+const hFFFFFFFF
+const h7FFFFFFF
+# yields 0
+ge
+store h1F0FC
+
+const hFFFFFFFF
+const h7FFFFFFF
+# yields 1
+uge
+store h1F100
+
+
+## compare 18532 to 234, no signedness magic here
+
+const 18532
+const 234
+# yields 0
+eq
+store h1F2E0
+
+const 18532
+const 234
+# yields 0
+lt
+store h1F2E4
+
+const 18532
+const 234
+# yields 0
+ult
+store h1F2E8
+
+const 18532
+const 234
+# yields 0
+le
+store h1F2EC
+
+const 18532
+const 234
+# yields 0
+ule
+store h1F2F0
+
+const 18532
+const 234
+# yields 1
+gt
+store h1F2F4
+
+const 18532
+const 234
+# yields 1
+ugt
+store h1F2F8
+
+const 18532
+const 234
+# yields 1
+ge
+store h1F2FC
+
+const 18532
+const 234
+# yields 1
+uge
+store h1F300
+
+
+## compare 123 to -1294081
+## -1294081 will be interpreted as big positive number for unsigned operations
+
+const 123
+const -1294081
+# yields 0
+eq
+store h1F4E0
+
+const 123
+const -1294081
+# yields 0
+lt
+store h1F4E4
+
+const 123
+const -1294081
+# yields 1
+ult
+store h1F4E8
+
+const 123
+const -1294081
+# yields 0
+le
+store h1F4EC
+
+const 123
+const -1294081
+# yields 1
+ule
+store h1F4F0
+
+const 123
+const -1294081
+# yields 1
+gt
+store h1F4F4
+
+const 123
+const -1294081
+# yields 0
+ugt
+store h1F4F8
+
+const 123
+const -1294081
+# yields 1
+ge
+store h1F4FC
+
+const 123
+const -1294081
+# yields 0
+uge
+store h1F500
+
+
+halt
diff --git a/tests/stack_machine_relop/test.v b/tests/stack_machine_relop/test.v
new file mode 120000
index 0000000..f5b6a59
--- /dev/null
+++ b/tests/stack_machine_relop/test.v
@@ -0,0 +1 @@
+../stack_machine_store/test.v
\ No newline at end of file
diff --git a/tests/stack_machine_relop/words_to_verify.mem b/tests/stack_machine_relop/words_to_verify.mem
new file mode 100644
index 0000000..b0564a3
--- /dev/null
+++ b/tests/stack_machine_relop/words_to_verify.mem
@@ -0,0 +1,40 @@
+// address  value
+   1EEE0    1
+   1EEE4    0
+   1EEE8    0
+   1EEEC    1
+   1EEF0    1
+   1EEF4    0
+   1EEF8    0
+   1EEFC    1
+   1EF00    1
+
+   1F0E0    0
+   1F0E4    1
+   1F0E8    0
+   1F0EC    1
+   1F0F0    0
+   1F0F4    0
+   1F0F8    1
+   1F0FC    0
+   1F100    1
+
+   1F2E0    0
+   1F2E4    0
+   1F2E8    0
+   1F2EC    0
+   1F2F0    0
+   1F2F4    1
+   1F2F8    1
+   1F2FC    1
+   1F300    1
+
+   1F4E0    0
+   1F4E4    0
+   1F4E8    1
+   1F4EC    0
+   1F4F0    1
+   1F4F4    1
+   1F4F8    0
+   1F4FC    1
+   1F500    0
diff --git a/tests/stack_machine_store/test.v b/tests/stack_machine_store/test.v
index 98ea2dc..61b80c8 100644
--- a/tests/stack_machine_store/test.v
+++ b/tests/stack_machine_store/test.v
@@ -184,7 +184,7 @@ module stack_machine_test();
       CLK <= 0;
       RST <= 1;
 
-      for (i = 0; i < 3500; i++) begin
+      for (i = 0; i < 7500; i++) begin
 	 #1;
 
 	 CLK <= ~CLK;
@@ -211,9 +211,9 @@ module stack_machine_test();
 
 	    $finish;
 	 end // if (M_finished)
-      end // for (i = 0; i < 3500; i++)
+      end // for (i = 0; i < 7500; i++)
 
-      $display("error: cpu hasn't finished its operations in 1750 ticks");
+      $display("error: cpu hasn't finished its operations in 3750 ticks");
       $finish;
    end // initial begin
 endmodule // stack_machine_test