From 186ab96276fa5a5095cea186fdde8a87f9ae9e41 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Remko=20Tron=C3=A7on?= <remko@el-tramo.be>
Date: Wed, 13 Mar 2019 20:01:17 +0100
Subject: [PATCH] Implement S>D

---
 src/waforth.wat                    |  8 ++++++++
 tests/standard-testsuite/core.f.js | 11 +++++++++++
 tests/tests.js                     | 14 ++++++++++++++
 3 files changed, 33 insertions(+)

diff --git a/src/waforth.wat b/src/waforth.wat
index cbc1d27..aed517c 100644
--- a/src/waforth.wat
+++ b/src/waforth.wat
@@ -1145,6 +1145,14 @@
     (call $ALIGN))
   (!def_word "S\"" "$Sq" !fImmediate)
 
+  ;; 6.1.2170
+  (func $s-to-d
+    (local $btos i32)
+    (i64.store (tee_local $btos (i32.sub (get_global $tos) (i32.const 4)))
+               (i64.extend_s/i32 (i32.load (get_local $btos))))
+    (set_global $tos (i32.add (get_global $tos) (i32.const 4))))
+  (!def_word "S>D" "$s-to-d")
+
   ;; 6.1.2216
   (func $SOURCE 
     (call $push (i32.const !inputBufferBase))
diff --git a/tests/standard-testsuite/core.f.js b/tests/standard-testsuite/core.f.js
index 84e3406..aa32530 100644
--- a/tests/standard-testsuite/core.f.js
+++ b/tests/standard-testsuite/core.f.js
@@ -270,5 +270,16 @@ T{ 1 ABS -> 1 }T
 T{ -1 ABS -> 1 }T
 T{ MIN-INT ABS -> MID-UINT+1 }T
 
+\\ ------------------------------------------------------------------------
+TESTING MULTIPLY: S>D * M* UM*
+
+T{ 0 S>D -> 0 0 }T
+T{ 1 S>D -> 1 0 }T
+T{ 2 S>D -> 2 0 }T
+T{ -1 S>D -> -1 -1 }T
+T{ -2 S>D -> -2 -1 }T
+T{ MIN-INT S>D -> MIN-INT -1 }T
+T{ MAX-INT S>D -> MAX-INT 0 }T
+
 
 `;
diff --git a/tests/tests.js b/tests/tests.js
index 03d7793..45e656f 100644
--- a/tests/tests.js
+++ b/tests/tests.js
@@ -1350,6 +1350,20 @@ function loadTests(wasmModule, arrayToBase64) {
       });
     });
 
+    describe("S>D", () => {
+      it("should work with positive number", () => {
+        run("2 S>D");
+        expect(stack[0]).to.eql(2);
+        expect(stack[1]).to.eql(0);
+      });
+
+      it("should work with negative number", () => {
+        run("-2 S>D");
+        expect(stack[0]).to.eql(-2);
+        expect(stack[1]).to.eql(-1);
+      });
+    });
+
     describe("system", () => {
       beforeEach(() => {
         core.loadPrelude();