From 7b31b119a50170ca80b495e0c29fb1102a8c9ec3 Mon Sep 17 00:00:00 2001
From: Danny Yoo <dyoo@cs.wpi.edu>
Date: Thu, 16 Feb 2012 16:56:04 -0500
Subject: [PATCH] trying to make simple numerics a bit faster

---
 compiler/kernel-primitives.rkt       |  8 ++++++++
 js-assembler/assemble-open-coded.rkt |  5 ++++-
 js-assembler/runtime-src/runtime.js  | 22 ++++++++++++++++++----
 3 files changed, 30 insertions(+), 5 deletions(-)

diff --git a/compiler/kernel-primitives.rkt b/compiler/kernel-primitives.rkt
index ac13bab..8f42b12 100644
--- a/compiler/kernel-primitives.rkt
+++ b/compiler/kernel-primitives.rkt
@@ -18,6 +18,7 @@
                                     '-
                                     '*
                                     '/
+                                    'zero?
                                     'add1
                                     'sub1
 				    'abs
@@ -127,6 +128,7 @@
                                            '-
                                            '*
                                            '/
+                                           'zero?
                                            'add1
                                            'sub1
                                            '<
@@ -178,6 +180,12 @@
            [else
             (make-IncorrectArity (make-ArityAtLeast 1))])]
 
+    [(eq? prim 'zero?)
+     (cond [(= arity 1)
+            (list 'number)]
+           [else
+            (make-IncorrectArity (make-ArityAtLeast 1))])]
+
     [(eq? prim 'add1)
      (cond [(= arity 1)
             (list 'number)]
diff --git a/js-assembler/assemble-open-coded.rkt b/js-assembler/assemble-open-coded.rkt
index f3fe0b7..b6f2ffe 100644
--- a/js-assembler/assemble-open-coded.rkt
+++ b/js-assembler/assemble-open-coded.rkt
@@ -38,7 +38,7 @@
           
           [(-)
            (cond [(empty? (rest checked-operands))
-                  (assemble-binop-chain "plt.baselib.numbers.subtract" (cons "0" checked-operands))]
+                  (format "RT.checkedNegate(M, ~a)" (first operands))]
                  [else
                   (assemble-binop-chain "plt.baselib.numbers.subtract" checked-operands)])]
           
@@ -51,6 +51,9 @@
           [(/)
            (assemble-binop-chain "plt.baselib.numbers.divide" checked-operands)]
 
+          [(zero?)
+           (format "RT.checkedIsZero(M, ~a)" (first operands))]
+
           [(add1)
            (format "RT.checkedAdd1(M, ~a)" (first operands))]
           
diff --git a/js-assembler/runtime-src/runtime.js b/js-assembler/runtime-src/runtime.js
index 639d80d..4f93f08 100644
--- a/js-assembler/runtime-src/runtime.js
+++ b/js-assembler/runtime-src/runtime.js
@@ -805,6 +805,13 @@
 
 
     //////////////////////////////////////////////////////////////////////
+    var checkedIsZero = function(M, n) {
+        if (typeof(n) === 'number') { return n===0; }
+        return plt.baselib.numbers.equals(
+            testArgument(M, 'number', isNumber, n, 0, 'zero?'),
+            0);
+    };
+
     var checkedAdd1 = function(M, n) {
         if (typeof(n) === 'number' && n < 9e15) { return n+1; }
         return plt.baselib.numbers.add(
@@ -815,9 +822,17 @@
     var checkedSub1 = function(M, n) {
         if (typeof(n) === 'number' && n > -9e15) { return n-1; }
         return plt.baselib.numbers.subtract(
-            testArgument(M, 'number', isNumber, n, 0, 'add1'),
+            testArgument(M, 'number', isNumber, n, 0, 'sub1'),
             1);
     };
+
+    var checkedNegate = function(M, n) {
+        if (typeof(n) === 'number') { return -n; }
+        return plt.baselib.numbers.subtract(
+            0,
+            testArgument(M, 'number', isNumber, n, 0, '-'));
+    };
+
     var checkedCar = function(M, v) {
         if (isPair(v)) { return v.first; }
         raiseArgumentTypeError(M, 'car', 'pair', 0, v);
@@ -829,9 +844,6 @@
     };
 
 
-
-
-
     //////////////////////////////////////////////////////////////////////
     //////////////////////////////////////////////////////////////////////
     //////////////////////////////////////////////////////////////////////
@@ -967,8 +979,10 @@
     exports['checkClosureAndArity'] = checkClosureAndArity;
     exports['checkPrimitiveArity'] = checkPrimitiveArity;
 
+    exports['checkedIsZero'] = checkedIsZero;
     exports['checkedAdd1'] = checkedAdd1;
     exports['checkedSub1'] = checkedSub1;
+    exports['checkedNegate'] = checkedNegate;
     exports['checkedCar'] = checkedCar;
     exports['checkedCdr'] = checkedCdr;
 }(this.plt, this.plt.baselib));
\ No newline at end of file