writer/hlsl: Implement isNormal

Change-Id: I5e5aa81db686b0205ffbf157542c0e85f28b5d5d
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/54323
Commit-Queue: Ben Clayton <bclayton@chromium.org>
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: David Neto <dneto@google.com>

src/writer/hlsl/generator_impl.cc

@@ -535,8 +535,7 @@ bool GeneratorImpl::EmitCall(std::ostream& pre,
     if (intrinsic->Type() == sem::IntrinsicType::kFrexp) {
       return EmitFrexpCall(pre, out, expr, intrinsic);
     } else if (intrinsic->Type() == sem::IntrinsicType::kIsNormal) {
-      diagnostics_.add_error("is_normal not supported in HLSL backend yet");
-      return false;
+      return EmitIsNormalCall(pre, out, expr, intrinsic);
     } else if (intrinsic->Type() == sem::IntrinsicType::kIgnore) {
       return EmitExpression(pre, out, expr->params()[0]);
     } else if (intrinsic->IsDataPacking()) {
@@ -670,6 +669,44 @@ bool GeneratorImpl::EmitFrexpCall(std::ostream& pre,
   return true;
 }
 
+bool GeneratorImpl::EmitIsNormalCall(std::ostream& pre,
+                                     std::ostream& out,
+                                     ast::CallExpression* expr,
+                                     const sem::Intrinsic* intrinsic) {
+  // HLSL doesn't have a isNormal intrinsic, we need to emulate
+  auto input = intrinsic->Parameters()[0];
+
+  std::string width;
+  if (auto* vec = input.type->As<sem::Vector>()) {
+    width = std::to_string(vec->size());
+  }
+
+  constexpr auto* kExponentMask = "0x7f80000";
+  constexpr auto* kMinNormalExponent = "0x0080000";
+  constexpr auto* kMaxNormalExponent = "0x7f00000";
+
+  auto exponent = generate_name("tint_isnormal_exponent");
+  auto clamped = generate_name("tint_isnormal_clamped");
+
+  std::stringstream ss;
+  ss << "uint" << width << " " << exponent << " = asuint(";
+  if (!EmitExpression(pre, ss, expr->params()[0])) {
+    return false;
+  }
+  ss << ") & " << kExponentMask << ";";
+
+  make_indent(ss << std::endl);
+  ss << "uint" << width << " " << clamped << " = "
+     << "clamp(" << exponent << ", " << kMinNormalExponent << ", "
+     << kMaxNormalExponent << ");";
+
+  make_indent(ss << std::endl);
+  pre << ss.str();
+
+  out << "(" << clamped << " == " << exponent << ")";
+  return true;
+}
+
 bool GeneratorImpl::EmitDataPackingCall(std::ostream& pre,
                                         std::ostream& out,
                                         ast::CallExpression* expr,

src/writer/hlsl/generator_impl.h

@@ -152,6 +152,16 @@ class GeneratorImpl : public TextGenerator {
                      std::ostream& out,
                      ast::CallExpression* expr,
                      const sem::Intrinsic* intrinsic);
+  /// Handles generating a call to the `isNormal()` intrinsic
+  /// @param pre the preamble of the expression stream
+  /// @param out the output of the expression stream
+  /// @param expr the call expression
+  /// @param intrinsic the semantic information for the intrinsic
+  /// @returns true if the call expression is emitted
+  bool EmitIsNormalCall(std::ostream& pre,
+                        std::ostream& out,
+                        ast::CallExpression* expr,
+                        const sem::Intrinsic* intrinsic);
   /// Handles generating a call to data packing intrinsic
   /// @param pre the preamble of the expression stream
   /// @param out the output of the expression stream

src/writer/hlsl/generator_impl_intrinsic_test.cc

@@ -347,6 +347,36 @@ TEST_F(HlslGeneratorImplTest_Intrinsic, Frexp_Vector_i32) {
 )"));
 }
 
+TEST_F(HlslGeneratorImplTest_Intrinsic, IsNormal_Scalar) {
+  auto* val = Var("val", ty.f32());
+  auto* call = Call("isNormal", val);
+  WrapInFunction(val, call);
+
+  GeneratorImpl& gen = SanitizeAndBuild();
+
+  ASSERT_TRUE(gen.Generate(out)) << gen.error();
+  EXPECT_THAT(result(), HasSubstr(R"(
+  uint tint_isnormal_exponent = asuint(val) & 0x7f80000;
+  uint tint_isnormal_clamped = clamp(tint_isnormal_exponent, 0x0080000, 0x7f00000);
+  (tint_isnormal_clamped == tint_isnormal_exponent);
+)"));
+}
+
+TEST_F(HlslGeneratorImplTest_Intrinsic, IsNormal_Vector) {
+  auto* val = Var("val", ty.vec3<f32>());
+  auto* call = Call("isNormal", val);
+  WrapInFunction(val, call);
+
+  GeneratorImpl& gen = SanitizeAndBuild();
+
+  ASSERT_TRUE(gen.Generate(out)) << gen.error();
+  EXPECT_THAT(result(), HasSubstr(R"(
+  uint3 tint_isnormal_exponent = asuint(val) & 0x7f80000;
+  uint3 tint_isnormal_clamped = clamp(tint_isnormal_exponent, 0x0080000, 0x7f00000);
+  (tint_isnormal_clamped == tint_isnormal_exponent);
+)"));
+}
+
 TEST_F(HlslGeneratorImplTest_Intrinsic, Pack4x8Snorm) {
   auto* call = Call("pack4x8snorm", "p1");
   Global("p1", ty.vec4<f32>(), ast::StorageClass::kPrivate);

test/intrinsics/gen/isNormal/863dcd.wgsl.expected.hlsl

@@ -1,30 +1,26 @@
-SKIP: FAILED
-
-
-fn isNormal_863dcd() {
-  var res : vec4<bool> = isNormal(vec4<f32>());
+void isNormal_863dcd() {
+  uint4 tint_isnormal_exponent = asuint(float4(0.0f, 0.0f, 0.0f, 0.0f)) & 0x7f80000;
+  uint4 tint_isnormal_clamped = clamp(tint_isnormal_exponent, 0x0080000, 0x7f00000);
+  bool4 res = (tint_isnormal_clamped == tint_isnormal_exponent);
 }
 
 struct tint_symbol {
-  [[builtin(position)]]
-  value : vec4<f32>;
+  float4 value : SV_Position;
 };
 
-[[stage(vertex)]]
-fn vertex_main() -> tint_symbol {
+tint_symbol vertex_main() {
   isNormal_863dcd();
-  let tint_symbol_1 : tint_symbol = tint_symbol(vec4<f32>());
+  const tint_symbol tint_symbol_1 = {float4(0.0f, 0.0f, 0.0f, 0.0f)};
   return tint_symbol_1;
 }
 
-[[stage(fragment)]]
-fn fragment_main() {
+void fragment_main() {
   isNormal_863dcd();
+  return;
 }
 
-[[stage(compute)]]
-fn compute_main() {
+[numthreads(1, 1, 1)]
+void compute_main() {
   isNormal_863dcd();
+  return;
 }
-
-Failed to generate: error: is_normal not supported in HLSL backend yet

test/intrinsics/gen/isNormal/b00ab1.wgsl.expected.hlsl

@@ -1,30 +1,26 @@
-SKIP: FAILED
-
-
-fn isNormal_b00ab1() {
-  var res : vec2<bool> = isNormal(vec2<f32>());
+void isNormal_b00ab1() {
+  uint2 tint_isnormal_exponent = asuint(float2(0.0f, 0.0f)) & 0x7f80000;
+  uint2 tint_isnormal_clamped = clamp(tint_isnormal_exponent, 0x0080000, 0x7f00000);
+  bool2 res = (tint_isnormal_clamped == tint_isnormal_exponent);
 }
 
 struct tint_symbol {
-  [[builtin(position)]]
-  value : vec4<f32>;
+  float4 value : SV_Position;
 };
 
-[[stage(vertex)]]
-fn vertex_main() -> tint_symbol {
+tint_symbol vertex_main() {
   isNormal_b00ab1();
-  let tint_symbol_1 : tint_symbol = tint_symbol(vec4<f32>());
+  const tint_symbol tint_symbol_1 = {float4(0.0f, 0.0f, 0.0f, 0.0f)};
   return tint_symbol_1;
 }
 
-[[stage(fragment)]]
-fn fragment_main() {
+void fragment_main() {
   isNormal_b00ab1();
+  return;
 }
 
-[[stage(compute)]]
-fn compute_main() {
+[numthreads(1, 1, 1)]
+void compute_main() {
   isNormal_b00ab1();
+  return;
 }
-
-Failed to generate: error: is_normal not supported in HLSL backend yet

test/intrinsics/gen/isNormal/c286b7.wgsl.expected.hlsl

@@ -1,30 +1,26 @@
-SKIP: FAILED
-
-
-fn isNormal_c286b7() {
-  var res : vec3<bool> = isNormal(vec3<f32>());
+void isNormal_c286b7() {
+  uint3 tint_isnormal_exponent = asuint(float3(0.0f, 0.0f, 0.0f)) & 0x7f80000;
+  uint3 tint_isnormal_clamped = clamp(tint_isnormal_exponent, 0x0080000, 0x7f00000);
+  bool3 res = (tint_isnormal_clamped == tint_isnormal_exponent);
 }
 
 struct tint_symbol {
-  [[builtin(position)]]
-  value : vec4<f32>;
+  float4 value : SV_Position;
 };
 
-[[stage(vertex)]]
-fn vertex_main() -> tint_symbol {
+tint_symbol vertex_main() {
   isNormal_c286b7();
-  let tint_symbol_1 : tint_symbol = tint_symbol(vec4<f32>());
+  const tint_symbol tint_symbol_1 = {float4(0.0f, 0.0f, 0.0f, 0.0f)};
   return tint_symbol_1;
 }
 
-[[stage(fragment)]]
-fn fragment_main() {
+void fragment_main() {
   isNormal_c286b7();
+  return;
 }
 
-[[stage(compute)]]
-fn compute_main() {
+[numthreads(1, 1, 1)]
+void compute_main() {
   isNormal_c286b7();
+  return;
 }
-
-Failed to generate: error: is_normal not supported in HLSL backend yet

test/intrinsics/gen/isNormal/c6e880.wgsl.expected.hlsl

@@ -1,30 +1,26 @@
-SKIP: FAILED
-
-
-fn isNormal_c6e880() {
-  var res : bool = isNormal(1.0);
+void isNormal_c6e880() {
+  uint tint_isnormal_exponent = asuint(1.0f) & 0x7f80000;
+  uint tint_isnormal_clamped = clamp(tint_isnormal_exponent, 0x0080000, 0x7f00000);
+  bool res = (tint_isnormal_clamped == tint_isnormal_exponent);
 }
 
 struct tint_symbol {
-  [[builtin(position)]]
-  value : vec4<f32>;
+  float4 value : SV_Position;
 };
 
-[[stage(vertex)]]
-fn vertex_main() -> tint_symbol {
+tint_symbol vertex_main() {
   isNormal_c6e880();
-  let tint_symbol_1 : tint_symbol = tint_symbol(vec4<f32>());
+  const tint_symbol tint_symbol_1 = {float4(0.0f, 0.0f, 0.0f, 0.0f)};
   return tint_symbol_1;
 }
 
-[[stage(fragment)]]
-fn fragment_main() {
+void fragment_main() {
   isNormal_c6e880();
+  return;
 }
 
-[[stage(compute)]]
-fn compute_main() {
+[numthreads(1, 1, 1)]
+void compute_main() {
   isNormal_c6e880();
+  return;
 }
-
-Failed to generate: error: is_normal not supported in HLSL backend yet