fix large f32 consts, fixes #817 (#820)

5 files changed, 24 insertions, 8 deletions

diff --git a/src/asm2wasm.h b/src/asm2wasm.h
index 377b6b20b..87fd10649 100644
--- a/src/asm2wasm.h
+++ b/src/asm2wasm.h
@@ -443,9 +443,13 @@ private:
 
   std::map<unsigned, Ref> tempNums;
 
-  Literal checkLiteral(Ref ast) {
+  Literal checkLiteral(Ref ast, bool rawIsInteger = true) {
     if (ast[0] == NUM) {
-      return Literal((int32_t)ast[1]->getInteger());
+      if (rawIsInteger) {
+        return Literal((int32_t)ast[1]->getInteger());
+      } else {
+        return Literal(ast[1]->getNumber());
+      }
     } else if (ast[0] == UNARY_PREFIX) {
       if (ast[1] == PLUS && ast[2][0] == NUM) {
         return Literal((double)ast[2][1]->getNumber());
@@ -1475,10 +1479,8 @@ Function* Asm2WasmBuilder::processFunction(Ref ast) {
         }
         if (name == Math_fround) {
           assert(ast[2]->size() == 1);
-          Literal lit = checkLiteral(ast[2][0]);
-          if (lit.type == i32) {
-            return builder.makeConst(Literal((float)lit.geti32()));
-          } else if (lit.type == f64) {
+          Literal lit = checkLiteral(ast[2][0], false /* raw is float */);
+          if (lit.type == f64) {
             return builder.makeConst(Literal((float)lit.getf64()));
           }
           auto ret = allocator.alloc<Unary>();
diff --git a/src/emscripten-optimizer/simple_ast.h b/src/emscripten-optimizer/simple_ast.h
index 3f0d363df..20de952c1 100644
--- a/src/emscripten-optimizer/simple_ast.h
+++ b/src/emscripten-optimizer/simple_ast.h
@@ -225,9 +225,9 @@ struct Value {
     return boo;
   }
 
-  int getInteger() { // convenience function to get a known integer
+  int32_t getInteger() { // convenience function to get a known integer
     assert(fmod(getNumber(), 1) == 0);
-    int ret = int(getNumber());
+    int32_t ret = getNumber();
     assert(double(ret) == getNumber()); // no loss in conversion
     return ret;
   }
diff --git a/test/unit.asm.js b/test/unit.asm.js
index 6ccf6c489..f002965ec 100644
--- a/test/unit.asm.js
+++ b/test/unit.asm.js
@@ -589,6 +589,10 @@ function asm(global, env, buffer) {
    return;
   }
 
+  function big_fround() {
+    return Math_fround(4294967295);
+  }
+
   function dropIgnoredImportsInIf($0,$1,$2) {
    $0 = $0|0;
    $1 = $1|0;
diff --git a/test/unit.fromasm.imprecise.no-opts b/test/unit.fromasm.imprecise.no-opts
index f372b2d57..608d68dcb 100644
--- a/test/unit.fromasm.imprecise.no-opts
+++ b/test/unit.fromasm.imprecise.no-opts
@@ -1677,6 +1677,11 @@
     )
     (return)
   )
+  (func $big_fround (result f32)
+    (return
+      (f32.const 4294967296)
+    )
+  )
   (func $dropIgnoredImportsInIf (param $$0 i32) (param $$1 i32) (param $$2 i32)
     (block $do-once
       (if
diff --git a/test/unit.fromasm.no-opts b/test/unit.fromasm.no-opts
index 0b90cb3b8..0b8a67ca7 100644
--- a/test/unit.fromasm.no-opts
+++ b/test/unit.fromasm.no-opts
@@ -1683,6 +1683,11 @@
     )
     (return)
   )
+  (func $big_fround (result f32)
+    (return
+      (f32.const 4294967296)
+    )
+  )
   (func $dropIgnoredImportsInIf (param $$0 i32) (param $$1 i32) (param $$2 i32)
     (block $do-once
       (if