roundy math ops (add etc.) in i64=1

src/parseTools.js

@@ -540,10 +540,15 @@ function makeI64(low, high) {
   }
 }
 
-// Splits a number (an integer in a double, possibly > 32 bits) into an I64_MODE 1 i64 value
+// Splits a number (an integer in a double, possibly > 32 bits) into an I64_MODE 1 i64 value.
+// Will suffer from rounding. margeI64 does the opposite.
 function splitI64(value) {
   assert(I64_MODE == 1);
-  return makeI64(value + '|0', 'Math.floor(' + value + '/4294967296)');
+  return '(tempInt=' + value + ',' + makeI64('tempInt|0', 'Math.floor(tempInt/4294967296)') + ')';
+}
+function mergeI64(value) {
+  assert(I64_MODE == 1);
+  return '(tempI64=' + value + ',tempI64[0]+tempI64[1]*4294967296)';
 }
 
 function makeCopyI64(value) {
@@ -1469,6 +1474,12 @@ function processMathop(item) { with(item) {
       }
       case 'select': return ident1 + ' ? ' + makeCopyI64(ident2) + ' : ' + makeCopyI64(ident3);
       case 'ptrtoint': case 'inttoptr': throw 'Pointers cannot be 64-bit!';
+      // Dangerous, rounded operations. TODO: Fully emulate
+      case 'add': return handleOverflow(splitI64(mergeI64(ident1) + '+' + mergeI64(ident2)), bits);
+      case 'sub': return handleOverflow(splitI64(mergeI64(ident1) + '-' + mergeI64(ident2)), bits);
+      case 'sdiv': case 'udiv': return splitI64(makeRounding(mergeI64(ident1) + '/' + mergeI64(ident2), bits, op[0] === 's'));
+      case 'mul': return handleOverflow(splitI64(mergeI64(ident1) + '*' + mergeI64(ident2)), bits);
+      case 'urem': return splitI64(mergeI64(ident1) + '%' + mergeI64(ident2));
       default: throw 'Unsupported i64 mode 1 op: ' + item.op;
     }
   }

src/preamble.js

@@ -382,6 +382,9 @@ var ABORT = false;
 
 var undef = 0;
 var tempValue, tempInt, tempBigInt;
+#if I64_MODE == 1
+var tempI64, tempI64b;
+#endif
 
 function abort(text) {
   print(text + ':\n' + (new Error).stack);

tests/runner.py

@@ -397,6 +397,7 @@ if 'benchmark' not in str(sys.argv):
 
         Settings.I64_MODE = 1
         src = r'''
+          #include <time.h>
           #include <stdio.h>
           #include <stdint.h>
 
@@ -414,6 +415,15 @@ if 'benchmark' not in str(sys.argv):
             t |= 12;
           }
 
+          int truthy() {
+            int x = time(0);
+            while (x > 10) {
+              x |= 7;
+              x /= 2;
+            }
+            return x < 3;
+          }
+
           int main()
           {
             int64_t x1 = 0x1234def123450789ULL;
@@ -434,13 +444,20 @@ if 'benchmark' not in str(sys.argv):
             modifier2(t);
             printf("*%Ld*\n", t);
 
-            // 
+            // Basic (rounded, for now) math
+            int64_t a = 0x1234def123450789ULL;
+            a--; if (truthy()) a--; // confuse optimizer
+            int64_t b = 0x1234000000450789ULL;
+            b++; if (truthy()) b--; // confuse optimizer
+            printf("*%Ld,%Ld,%Ld*\n", a+b, a-b, a*3, a/5);
+
             return 0;
           }
         '''
         self.do_run(src, '*1311918518731868200\n0,0,0,1,1\n1,0,1,0,1*\n*245127260211081*\n*245127260209443*\n' +
                          '*18446744073709552000*\n*576460752303423500*\n' +
-                         'm1: 127\n*123*\n*127*\n')
+                         'm1: 127\n*123*\n*127*\n' +
+                         '*2623591910208049000,245127255687168,3935755556195604500*\n')
 
 
     def test_unsigned(self):