Implement f{32,64}.sub instructions

wasmx · Aug 14, 2020 · 7edb382 · 7edb382
1 parent 7106040
commit 7edb382
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Showing 2 changed files with 77 additions and 2 deletions.
diff --git a/lib/fizzy/execute.cpp b/lib/fizzy/execute.cpp
@@ -1573,6 +1573,11 @@ ExecutionResult execute(Instance& instance, FuncIdx func_idx, span<const Value>
             binary_op(stack, std::plus<float>{});
             break;
         }
+        case Instr::f32_sub:
+        {
+            binary_op(stack, std::minus<float>{});
+            break;
+        }
         case Instr::f32_mul:
         {
             binary_op(stack, std::multiplies<float>{});
@@ -1625,6 +1630,11 @@ ExecutionResult execute(Instance& instance, FuncIdx func_idx, span<const Value>
             binary_op(stack, std::plus<double>{});
             break;
         }
+        case Instr::f64_sub:
+        {
+            binary_op(stack, std::minus<double>{});
+            break;
+        }
         case Instr::f64_mul:
         {
             binary_op(stack, std::multiplies<double>{});
@@ -1789,12 +1799,10 @@ ExecutionResult execute(Instance& instance, FuncIdx func_idx, span<const Value>
         case Instr::f32_floor:
         case Instr::f32_trunc:
         case Instr::f32_nearest:
-        case Instr::f32_sub:
         case Instr::f64_ceil:
         case Instr::f64_floor:
         case Instr::f64_trunc:
         case Instr::f64_nearest:
-        case Instr::f64_sub:
         case Instr::f32_demote_f64:
         case Instr::i32_reinterpret_f32:
         case Instr::i64_reinterpret_f64:

diff --git a/test/unittests/execute_floating_point_test.cpp b/test/unittests/execute_floating_point_test.cpp
@@ -277,6 +277,7 @@ TYPED_TEST(execute_floating_point_types, binop_nan_propagation)
     // Only f32 variants, but f64 variants are going to be covered as well.
     constexpr Instr opcodes[] = {
         Instr::f32_add,
+        Instr::f32_sub,
         Instr::f32_mul,
         Instr::f32_div,
         Instr::f32_min,
@@ -538,6 +539,72 @@ TYPED_TEST(execute_floating_point_types, add)
     EXPECT_THAT(exec(TypeParam{0x0.287p2}, TypeParam{0x1.FFp4}), Result(TypeParam{0x1.048Ep5}));
 }
 
+TYPED_TEST(execute_floating_point_types, sub)
+{
+    using FP = FP<TypeParam>;
+    using Limits = typename FP::Limits;
+
+    auto instance = instantiate(parse(this->get_binop_code(Instr::f32_sub)));
+    const auto exec = [&](auto arg1, auto arg2) { return execute(*instance, 0, {arg1, arg2}); };
+
+    // fsub(+-inf, +-inf) = nan:canonical
+    EXPECT_THAT(exec(Limits::infinity(), Limits::infinity()), CanonicalNaN(TypeParam{}));
+    EXPECT_THAT(exec(-Limits::infinity(), -Limits::infinity()), CanonicalNaN(TypeParam{}));
+
+    // fsub(+-inf, -+inf) = +-inf
+    EXPECT_THAT(exec(Limits::infinity(), -Limits::infinity()), Result(Limits::infinity()));
+    EXPECT_THAT(exec(-Limits::infinity(), Limits::infinity()), Result(-Limits::infinity()));
+
+    // fsub(+-O, +-0) = +0
+    EXPECT_THAT(exec(TypeParam{0.0}, TypeParam{0.0}), Result(TypeParam{0.0}));
+    EXPECT_THAT(exec(-TypeParam{0.0}, -TypeParam{0.0}), Result(TypeParam{0.0}));
+
+    // fsub(+-0, -+0) = +-0
+    EXPECT_THAT(exec(TypeParam{0.0}, -TypeParam{0.0}), Result(TypeParam{0.0}));
+    EXPECT_THAT(exec(-TypeParam{0.0}, TypeParam{0.0}), Result(-TypeParam{0.0}));
+
+    // fsub(z1, +-0) = z1  (for z1 = +-inf)
+    EXPECT_THAT(exec(Limits::infinity(), TypeParam{0.0}), Result(Limits::infinity()));
+    EXPECT_THAT(exec(Limits::infinity(), -TypeParam{0.0}), Result(Limits::infinity()));
+    EXPECT_THAT(exec(-Limits::infinity(), TypeParam{0.0}), Result(-Limits::infinity()));
+    EXPECT_THAT(exec(-Limits::infinity(), -TypeParam{0.0}), Result(-Limits::infinity()));
+
+    for (const auto q : this->positive_special_values)
+    {
+        // fsub(z1, +-inf) = -+inf  (for z1 = +-q)
+        EXPECT_THAT(exec(q, Limits::infinity()), Result(-Limits::infinity()));
+        EXPECT_THAT(exec(q, -Limits::infinity()), Result(Limits::infinity()));
+        EXPECT_THAT(exec(-q, Limits::infinity()), Result(-Limits::infinity()));
+        EXPECT_THAT(exec(-q, -Limits::infinity()), Result(Limits::infinity()));
+
+        // fsub(+-inf, z2) = +-inf  (for z2 = +-q)
+        EXPECT_THAT(exec(Limits::infinity(), q), Result(Limits::infinity()));
+        EXPECT_THAT(exec(-Limits::infinity(), q), Result(-Limits::infinity()));
+        EXPECT_THAT(exec(Limits::infinity(), -q), Result(Limits::infinity()));
+        EXPECT_THAT(exec(-Limits::infinity(), -q), Result(-Limits::infinity()));
+
+        // fsub(z1, +-0) = z1  (for z1 = +-q)
+        EXPECT_THAT(exec(q, TypeParam{0.0}), Result(q));
+        EXPECT_THAT(exec(q, -TypeParam{0.0}), Result(q));
+        EXPECT_THAT(exec(-q, TypeParam{0.0}), Result(-q));
+        EXPECT_THAT(exec(-q, -TypeParam{0.0}), Result(-q));
+
+        // fsub(+-0, +-q2) = -+q2
+        EXPECT_THAT(exec(TypeParam{0.0}, q), Result(-q));
+        EXPECT_THAT(exec(-TypeParam{0.0}, -q), Result(q));
+
+        // Not part of the spec.
+        EXPECT_THAT(exec(TypeParam{0.0}, -q), Result(q));
+        EXPECT_THAT(exec(-TypeParam{0.0}, q), Result(-q));
+
+        // fsub(+-q, +-q) = +0
+        EXPECT_THAT(exec(q, q), Result(TypeParam{0.0}));
+        EXPECT_THAT(exec(-q, -q), Result(TypeParam{0.0}));
+    }
+
+    EXPECT_THAT(exec(TypeParam{0x1.048Ep5}, TypeParam{0x1.FFp4}), Result(TypeParam{0x0.287p2}));
+}
+
 TYPED_TEST(execute_floating_point_types, mul)
 {
     using FP = FP<TypeParam>;