Implement f64.promote_f32 instruction

wasmx · Aug 9, 2020 · 128ebd3 · 128ebd3
1 parent 9e82ffc
commit 128ebd3
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diff --git a/lib/fizzy/execute.cpp b/lib/fizzy/execute.cpp
@@ -1543,6 +1543,11 @@ ExecutionResult execute(Instance& instance, FuncIdx func_idx, span<const Value>
             convert<uint64_t, double>(stack);
             break;
         }
+        case Instr::f64_promote_f32:
+        {
+            stack.top() = double{stack.top().f32};
+            break;
+        }
 
         case Instr::f32_load:
         case Instr::f64_load:
@@ -1587,7 +1592,6 @@ ExecutionResult execute(Instance& instance, FuncIdx func_idx, span<const Value>
         case Instr::f64_max:
         case Instr::f64_copysign:
         case Instr::f32_demote_f64:
-        case Instr::f64_promote_f32:
         case Instr::i32_reinterpret_f32:
         case Instr::i64_reinterpret_f64:
         case Instr::f32_reinterpret_i32:

diff --git a/test/unittests/execute_floating_point_test.cpp b/test/unittests/execute_floating_point_test.cpp
@@ -71,6 +71,51 @@ TEST(execute_floating_point, f64_add)
     EXPECT_THAT(execute(*instance, 0, {1.0011, 6.0066}), Result(7.0077));
 }
 
+TEST(execute_floating_point, f64_promote_f32)
+{
+    /* wat2wasm
+    (func (param f32) (result f64)
+      local.get 0
+      f64.promote_f32
+    )
+    */
+    auto wasm = from_hex("0061736d0100000001060160017d017c030201000a070105002000bb0b");
+    auto instance = instantiate(parse(wasm));
+
+    using f32_limits = std::numeric_limits<float>;
+    using f64_limits = std::numeric_limits<double>;
+
+    EXPECT_THAT(execute(*instance, 0, {0.0f}), Result(0.0));
+    EXPECT_THAT(execute(*instance, 0, {-0.0f}), Result(-0.0));
+    EXPECT_THAT(execute(*instance, 0, {1.0f}), Result(1.0));
+    EXPECT_THAT(execute(*instance, 0, {-1.0f}), Result(-1.0));
+
+    EXPECT_THAT(execute(*instance, 0, {f32_limits::max()}), Result(double{f32_limits::max()}));
+    EXPECT_THAT(execute(*instance, 0, {f32_limits::min()}), Result(double{f32_limits::min()}));
+    EXPECT_THAT(
+        execute(*instance, 0, {f32_limits::lowest()}), Result(double{f32_limits::lowest()}));
+
+    EXPECT_THAT(execute(*instance, 0, {f32_limits::infinity()}), Result(f64_limits::infinity()));
+    EXPECT_THAT(execute(*instance, 0, {-f32_limits::infinity()}), Result(-f64_limits::infinity()));
+
+    // The canonical NaN must result in canonical NaN (only the top bit set).
+    EXPECT_THAT(execute(*instance, 0, {FP32::nan(FP32::canon)}), Result(FP64::nan(FP64::canon)));
+
+    // An arithmetic NaN must result in any arithmetic NaN (payload >= canonical payload).
+    // The spec allows the result to be the canonical NaN, but in the current implementation it
+    // is not the case and the check is more restrictive than the spec requires.
+    const auto res1 = execute(*instance, 0, {FP32::nan(FP32::canon + 1)});
+    ASSERT_TRUE(!res1.trapped && res1.has_value);
+    EXPECT_GT(FP{res1.value.f64}.nan_payload(), FP64::canon);
+
+    // Other NaN must also result in arithmetic NaN.
+    // The spec allows the result to be the canonical NaN, but in the current implementation it
+    // is not the case and the check is more restrictive than the spec requires.
+    const auto res2 = execute(*instance, 0, {FP32::nan(1)});
+    ASSERT_TRUE(!res2.trapped && res2.has_value);
+    EXPECT_GT(FP{res2.value.f64}.nan_payload(), FP64::canon);
+}
+
 
 template <typename SrcT, typename DstT>
 struct ConversionPairWasmTraits;