correct signs in equality comparisons

2 files changed, 19 insertions, 7 deletions

diff --git a/src/jsifier.js b/src/jsifier.js
index 44f2ffe0..b1b8797b 100644
--- a/src/jsifier.js
+++ b/src/jsifier.js
@@ -874,8 +874,13 @@ function JSify(data, functionsOnly, givenFunctions, givenGlobalVariables) {
           case 'ugt': case 'sgt': return ident1 + ' > ' + ident2;
           case 'ult': case 'slt': return ident1 + ' < ' + ident2;
           // We use loose comparisons, which allows false == 0 to be true, etc. Ditto in fcmp
-          case 'ne': case 'une': return ident1 + ' != ' + ident2;
-          case 'eq': return ident1 + ' == ' + ident2;
+          case 'ne': case 'eq': {
+            // We must sign them, so we do not compare -1 to 255 (could have unsigned them both too)
+            // since LLVM tells us if <=, >= etc. comparisons are signed, but not == and !=.
+            ident1 = makeSignOp(ident1, type, 're');
+            ident2 = makeSignOp(ident2, type, 're');
+            return ident1 + (variant === 'eq' ? '==' : '!=') + ident2;
+          }
           default: throw 'Unknown icmp variant: ' + variant;
         }
       }
diff --git a/tests/runner.py b/tests/runner.py
index ebd4e8ba..662360a3 100644
--- a/tests/runner.py
+++ b/tests/runner.py
@@ -381,10 +381,15 @@ if 'benchmark' not in sys.argv:
             int y32 = hold+50;
             printf("*%u,%u*\\n", hold, y32);
 
+            // Comparisons
+            x8 = 0;
+            for (int i = 0; i < 254; i++) x8++; // make it an actual 254 in JS - not a -2
+            printf("*%d,%d*\\n", x8+1 == 0xff, x8+1 != 0xff); // 0xff may be '-1' in the bitcode
+
             return 0;
           }
         '''
-        self.do_test(src, '*4294967295,0,4294967219*\n*-1,1,-1,1*\n*-2,1,-2,1*\n*246,296*')
+        self.do_test(src, '*4294967295,0,4294967219*\n*-1,1,-1,1*\n*-2,1,-2,1*\n*246,296*\n*1,0*')
 
     def test_bitfields(self):
         global SAFE_HEAP; SAFE_HEAP = 0 # bitfields do loads on invalid areas, by design
@@ -1639,9 +1644,8 @@ if 'benchmark' not in sys.argv:
                    force_c=True)
 
     def test_openjpeg(self):
-      if COMPILER == LLVM_GCC: return # Not sure why, but fails in gcc - generally correct, but noisy output
-
       global SAFE_HEAP; SAFE_HEAP = 0 # Very slow
+      global CORRECT_SIGNS; CORRECT_SIGNS = 1 # Needed for some comparisons, at least in gcc
 
       original_j2k = path_from_root('tests', 'openjpeg', 'syntensity_lobby_s.j2k')
 
@@ -1672,11 +1676,14 @@ if 'benchmark' not in sys.argv:
       # check our output by comparing the average pixel difference
       def image_compare(output):
         # Get the image generated by JS, from the JSON.stringify'd array
-        m = re.search('\[[\d, ]*\]', output)
+        m = re.search('\[[\d, -]*\]', output)
         try:
           js_data = eval(m.group(0))
         except AttributeError:
           print 'Failed to find proper image output in: ' + output
+          raise
+
+        js_data = map(lambda x: x if x >= 0 else 256+x, js_data) # Our output may be signed, so unsign it
 
         # Generate the native code output using lli
         lli_file = os.path.join(self.get_dir(), 'lli.raw')
@@ -1697,7 +1704,7 @@ if 'benchmark' not in sys.argv:
         diff_mean = diff_total/float(num)
 
         image_mean = 83
-        print '[image stats:', js_mean, image_mean, lli_mean, diff_mean, num, ']'
+        #print '[image stats:', js_mean, image_mean, lli_mean, diff_mean, num, ']'
         assert abs(js_mean - image_mean) < 2
         assert abs(lli_mean - image_mean) < 2
         assert diff_mean < 2 # XXX All of these are not quite right...