do not assume anything about the top bits in llvm intrinsics receivin…

…g i8/i16 values - while normally we can assume that the top bits are clear due to how LLVM creates the call, if the call is an ffi or constructed in a non-clang way (see rust-lang/rust#39119) then we must be careful
emscripten-core · Jan 17, 2017 · 12c1945 · 12c1945
1 parent 62dfd0f
commit 12c1945
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/src/library.js b/src/library.js
@@ -951,15 +951,15 @@ LibraryManager.library = {
   llvm_ctlz_i8: function(x, isZeroUndef) {
     x = x | 0;
     isZeroUndef = isZeroUndef | 0;
-    return (Math_clz32(x) | 0) - 24 | 0;
+    return (Math_clz32(x & 0xff) | 0) - 24 | 0;
   },
 
   llvm_ctlz_i16__asm: true,
   llvm_ctlz_i16__sig: 'ii',
   llvm_ctlz_i16: function(x, isZeroUndef) {
     x = x | 0;
     isZeroUndef = isZeroUndef | 0;
-    return (Math_clz32(x) | 0) - 16 | 0
+    return (Math_clz32(x & 0xffff) | 0) - 16 | 0
   },
 
   llvm_ctlz_i64__asm: true,