| // Copyright 2022 The Tint Authors. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| #include "src/tint/transform/builtin_polyfill.h" |
| |
| #include <algorithm> |
| #include <tuple> |
| #include <unordered_map> |
| #include <utility> |
| |
| #include "src/tint/program_builder.h" |
| #include "src/tint/sem/builtin.h" |
| #include "src/tint/sem/call.h" |
| #include "src/tint/utils/map.h" |
| |
| using namespace tint::number_suffixes; // NOLINT |
| |
| TINT_INSTANTIATE_TYPEINFO(tint::transform::BuiltinPolyfill); |
| TINT_INSTANTIATE_TYPEINFO(tint::transform::BuiltinPolyfill::Config); |
| |
| namespace tint::transform { |
| |
| /// BinaryOpSignature is tuple of a binary op, LHS type and RHS type |
| using BinaryOpSignature = std::tuple<ast::BinaryOp, const sem::Type*, const sem::Type*>; |
| |
| /// PIMPL state for the transform |
| struct BuiltinPolyfill::State { |
| /// Constructor |
| /// @param c the CloneContext |
| /// @param p the builtins to polyfill |
| State(CloneContext& c, Builtins p) : ctx(c), polyfill(p) {} |
| |
| //////////////////////////////////////////////////////////////////////////// |
| // Function polyfills |
| //////////////////////////////////////////////////////////////////////////// |
| |
| /// Builds the polyfill function for the `acosh` builtin |
| /// @param ty the parameter and return type for the function |
| /// @return the polyfill function name |
| Symbol acosh(const sem::Type* ty) { |
| auto name = b.Symbols().New("tint_acosh"); |
| uint32_t width = WidthOf(ty); |
| |
| auto V = [&](AFloat value) -> const ast::Expression* { |
| const ast::Expression* expr = b.Expr(value); |
| if (width == 1) { |
| return expr; |
| } |
| return b.Construct(T(ty), expr); |
| }; |
| |
| utils::Vector<const ast::Statement*, 4> body; |
| switch (polyfill.acosh) { |
| case Level::kFull: |
| // return log(x + sqrt(x*x - 1)); |
| body.Push(b.Return( |
| b.Call("log", b.Add("x", b.Call("sqrt", b.Sub(b.Mul("x", "x"), 1_a)))))); |
| break; |
| case Level::kRangeCheck: { |
| // return select(acosh(x), 0, x < 1); |
| body.Push(b.Return( |
| b.Call("select", b.Call("acosh", "x"), V(0.0_a), b.LessThan("x", V(1.0_a))))); |
| break; |
| } |
| default: |
| TINT_ICE(Transform, b.Diagnostics()) |
| << "unhandled polyfill level: " << static_cast<int>(polyfill.acosh); |
| return {}; |
| } |
| |
| b.Func(name, utils::Vector{b.Param("x", T(ty))}, T(ty), body); |
| |
| return name; |
| } |
| |
| /// Builds the polyfill function for the `asinh` builtin |
| /// @param ty the parameter and return type for the function |
| /// @return the polyfill function name |
| Symbol asinh(const sem::Type* ty) { |
| auto name = b.Symbols().New("tint_sinh"); |
| |
| // return log(x + sqrt(x*x + 1)); |
| b.Func(name, utils::Vector{b.Param("x", T(ty))}, T(ty), |
| utils::Vector{ |
| b.Return(b.Call("log", b.Add("x", b.Call("sqrt", b.Add(b.Mul("x", "x"), 1_a))))), |
| }); |
| |
| return name; |
| } |
| |
| /// Builds the polyfill function for the `atanh` builtin |
| /// @param ty the parameter and return type for the function |
| /// @return the polyfill function name |
| Symbol atanh(const sem::Type* ty) { |
| auto name = b.Symbols().New("tint_atanh"); |
| uint32_t width = WidthOf(ty); |
| |
| auto V = [&](AFloat value) -> const ast::Expression* { |
| const ast::Expression* expr = b.Expr(value); |
| if (width == 1) { |
| return expr; |
| } |
| return b.Construct(T(ty), expr); |
| }; |
| |
| utils::Vector<const ast::Statement*, 1> body; |
| switch (polyfill.atanh) { |
| case Level::kFull: |
| // return log((1+x) / (1-x)) * 0.5 |
| body.Push( |
| b.Return(b.Mul(b.Call("log", b.Div(b.Add(1_a, "x"), b.Sub(1_a, "x"))), 0.5_a))); |
| break; |
| case Level::kRangeCheck: |
| // return select(atanh(x), 0, x >= 1); |
| body.Push(b.Return(b.Call("select", b.Call("atanh", "x"), V(0.0_a), |
| b.GreaterThanEqual("x", V(1.0_a))))); |
| break; |
| default: |
| TINT_ICE(Transform, b.Diagnostics()) |
| << "unhandled polyfill level: " << static_cast<int>(polyfill.acosh); |
| return {}; |
| } |
| |
| b.Func(name, utils::Vector{b.Param("x", T(ty))}, T(ty), body); |
| |
| return name; |
| } |
| |
| /// Builds the polyfill function for the `clamp` builtin when called with integer arguments |
| /// (scalar or vector) |
| /// @param ty the parameter and return type for the function |
| /// @return the polyfill function name |
| Symbol clampInteger(const sem::Type* ty) { |
| auto name = b.Symbols().New("tint_clamp"); |
| |
| b.Func(name, |
| utils::Vector{ |
| b.Param("e", T(ty)), |
| b.Param("low", T(ty)), |
| b.Param("high", T(ty)), |
| }, |
| T(ty), |
| utils::Vector{ |
| // return min(max(e, low), high); |
| b.Return(b.Call("min", b.Call("max", "e", "low"), "high")), |
| }); |
| return name; |
| } |
| |
| /// Builds the polyfill function for the `countLeadingZeros` builtin |
| /// @param ty the parameter and return type for the function |
| /// @return the polyfill function name |
| Symbol countLeadingZeros(const sem::Type* ty) { |
| auto name = b.Symbols().New("tint_count_leading_zeros"); |
| uint32_t width = WidthOf(ty); |
| |
| // Returns either u32 or vecN<u32> |
| auto U = [&]() -> const ast::Type* { |
| if (width == 1) { |
| return b.ty.u32(); |
| } |
| return b.ty.vec<u32>(width); |
| }; |
| auto V = [&](uint32_t value) -> const ast::Expression* { |
| return ScalarOrVector(width, u32(value)); |
| }; |
| b.Func(name, |
| utils::Vector{ |
| b.Param("v", T(ty)), |
| }, |
| T(ty), |
| utils::Vector{ |
| // var x = U(v); |
| b.Decl(b.Var("x", b.Construct(U(), b.Expr("v")))), |
| // let b16 = select(0, 16, x <= 0x0000ffff); |
| b.Decl(b.Let( |
| "b16", b.Call("select", V(0), V(16), b.LessThanEqual("x", V(0x0000ffff))))), |
| // x = x << b16; |
| b.Assign("x", b.Shl("x", "b16")), |
| // let b8 = select(0, 8, x <= 0x00ffffff); |
| b.Decl(b.Let("b8", |
| b.Call("select", V(0), V(8), b.LessThanEqual("x", V(0x00ffffff))))), |
| // x = x << b8; |
| b.Assign("x", b.Shl("x", "b8")), |
| // let b4 = select(0, 4, x <= 0x0fffffff); |
| b.Decl(b.Let("b4", |
| b.Call("select", V(0), V(4), b.LessThanEqual("x", V(0x0fffffff))))), |
| // x = x << b4; |
| b.Assign("x", b.Shl("x", "b4")), |
| // let b2 = select(0, 2, x <= 0x3fffffff); |
| b.Decl(b.Let("b2", |
| b.Call("select", V(0), V(2), b.LessThanEqual("x", V(0x3fffffff))))), |
| // x = x << b2; |
| b.Assign("x", b.Shl("x", "b2")), |
| // let b1 = select(0, 1, x <= 0x7fffffff); |
| b.Decl(b.Let("b1", |
| b.Call("select", V(0), V(1), b.LessThanEqual("x", V(0x7fffffff))))), |
| // let is_zero = select(0, 1, x == 0); |
| b.Decl(b.Let("is_zero", b.Call("select", V(0), V(1), b.Equal("x", V(0))))), |
| // return R((b16 | b8 | b4 | b2 | b1) + zero); |
| b.Return(b.Construct( |
| T(ty), |
| b.Add(b.Or(b.Or(b.Or(b.Or("b16", "b8"), "b4"), "b2"), "b1"), "is_zero"))), |
| }); |
| return name; |
| } |
| |
| /// Builds the polyfill function for the `countTrailingZeros` builtin |
| /// @param ty the parameter and return type for the function |
| /// @return the polyfill function name |
| Symbol countTrailingZeros(const sem::Type* ty) { |
| auto name = b.Symbols().New("tint_count_trailing_zeros"); |
| uint32_t width = WidthOf(ty); |
| |
| // Returns either u32 or vecN<u32> |
| auto U = [&]() -> const ast::Type* { |
| if (width == 1) { |
| return b.ty.u32(); |
| } |
| return b.ty.vec<u32>(width); |
| }; |
| auto V = [&](uint32_t value) -> const ast::Expression* { |
| return ScalarOrVector(width, u32(value)); |
| }; |
| auto B = [&](const ast::Expression* value) -> const ast::Expression* { |
| if (width == 1) { |
| return b.Construct<bool>(value); |
| } |
| return b.Construct(b.ty.vec<bool>(width), value); |
| }; |
| b.Func( |
| name, |
| utils::Vector{ |
| b.Param("v", T(ty)), |
| }, |
| T(ty), |
| utils::Vector{ |
| // var x = U(v); |
| b.Decl(b.Var("x", b.Construct(U(), b.Expr("v")))), |
| // let b16 = select(16, 0, bool(x & 0x0000ffff)); |
| b.Decl(b.Let("b16", b.Call("select", V(16), V(0), B(b.And("x", V(0x0000ffff)))))), |
| // x = x >> b16; |
| b.Assign("x", b.Shr("x", "b16")), |
| // let b8 = select(8, 0, bool(x & 0x000000ff)); |
| b.Decl(b.Let("b8", b.Call("select", V(8), V(0), B(b.And("x", V(0x000000ff)))))), |
| // x = x >> b8; |
| b.Assign("x", b.Shr("x", "b8")), |
| // let b4 = select(4, 0, bool(x & 0x0000000f)); |
| b.Decl(b.Let("b4", b.Call("select", V(4), V(0), B(b.And("x", V(0x0000000f)))))), |
| // x = x >> b4; |
| b.Assign("x", b.Shr("x", "b4")), |
| // let b2 = select(2, 0, bool(x & 0x00000003)); |
| b.Decl(b.Let("b2", b.Call("select", V(2), V(0), B(b.And("x", V(0x00000003)))))), |
| // x = x >> b2; |
| b.Assign("x", b.Shr("x", "b2")), |
| // let b1 = select(1, 0, bool(x & 0x00000001)); |
| b.Decl(b.Let("b1", b.Call("select", V(1), V(0), B(b.And("x", V(0x00000001)))))), |
| // let is_zero = select(0, 1, x == 0); |
| b.Decl(b.Let("is_zero", b.Call("select", V(0), V(1), b.Equal("x", V(0))))), |
| // return R((b16 | b8 | b4 | b2 | b1) + zero); |
| b.Return(b.Construct( |
| T(ty), |
| b.Add(b.Or(b.Or(b.Or(b.Or("b16", "b8"), "b4"), "b2"), "b1"), "is_zero"))), |
| }); |
| return name; |
| } |
| |
| /// Builds the polyfill function for the `extractBits` builtin |
| /// @param ty the parameter and return type for the function |
| /// @return the polyfill function name |
| Symbol extractBits(const sem::Type* ty) { |
| auto name = b.Symbols().New("tint_extract_bits"); |
| uint32_t width = WidthOf(ty); |
| |
| constexpr uint32_t W = 32u; // 32-bit |
| |
| auto vecN_u32 = [&](const ast::Expression* value) -> const ast::Expression* { |
| if (width == 1) { |
| return value; |
| } |
| return b.Construct(b.ty.vec<u32>(width), value); |
| }; |
| |
| utils::Vector<const ast::Statement*, 8> body{ |
| b.Decl(b.Let("s", b.Call("min", "offset", u32(W)))), |
| b.Decl(b.Let("e", b.Call("min", u32(W), b.Add("s", "count")))), |
| }; |
| |
| switch (polyfill.extract_bits) { |
| case Level::kFull: |
| body.Push(b.Decl(b.Let("shl", b.Sub(u32(W), "e")))); |
| body.Push(b.Decl(b.Let("shr", b.Add("shl", "s")))); |
| // Here we don't want the shl and shr modulos the rhs, so handle the `rhs >= 32u` |
| // cases using `select`. In order to handle the signed shr `lhs >> rhs` corrently, |
| // use `(lhs >> 31u) >> 1u` if `rhs >= 32u`. |
| body.Push(b.Decl(b.Let("shl_result", b.Call("select", b.Construct(T(ty)), |
| b.Shl("v", vecN_u32(b.Expr("shl"))), |
| b.LessThan("shl", 32_u))))); |
| body.Push(b.Return(b.Call( |
| "select", |
| b.Shr(b.Shr("shl_result", vecN_u32(b.Expr(31_u))), vecN_u32(b.Expr(1_u))), |
| b.Shr("shl_result", vecN_u32(b.Expr("shr"))), b.LessThan("shr", 32_u)) |
| |
| )); |
| break; |
| case Level::kClampParameters: |
| body.Push(b.Return(b.Call("extractBits", "v", "s", b.Sub("e", "s")))); |
| break; |
| default: |
| TINT_ICE(Transform, b.Diagnostics()) |
| << "unhandled polyfill level: " << static_cast<int>(polyfill.extract_bits); |
| return {}; |
| } |
| |
| b.Func(name, |
| utils::Vector{ |
| b.Param("v", T(ty)), |
| b.Param("offset", b.ty.u32()), |
| b.Param("count", b.ty.u32()), |
| }, |
| T(ty), std::move(body)); |
| |
| return name; |
| } |
| |
| /// Builds the polyfill function for the `firstLeadingBit` builtin |
| /// @param ty the parameter and return type for the function |
| /// @return the polyfill function name |
| Symbol firstLeadingBit(const sem::Type* ty) { |
| auto name = b.Symbols().New("tint_first_leading_bit"); |
| uint32_t width = WidthOf(ty); |
| |
| // Returns either u32 or vecN<u32> |
| auto U = [&]() -> const ast::Type* { |
| if (width == 1) { |
| return b.ty.u32(); |
| } |
| return b.ty.vec<u32>(width); |
| }; |
| auto V = [&](uint32_t value) -> const ast::Expression* { |
| return ScalarOrVector(width, u32(value)); |
| }; |
| auto B = [&](const ast::Expression* value) -> const ast::Expression* { |
| if (width == 1) { |
| return b.Construct<bool>(value); |
| } |
| return b.Construct(b.ty.vec<bool>(width), value); |
| }; |
| |
| const ast::Expression* x = nullptr; |
| if (ty->is_unsigned_scalar_or_vector()) { |
| x = b.Expr("v"); |
| } else { |
| // If ty is signed, then the value is inverted if the sign is negative |
| x = b.Call("select", // |
| b.Construct(U(), "v"), // |
| b.Construct(U(), b.Complement("v")), // |
| b.LessThan("v", ScalarOrVector(width, 0_i))); |
| } |
| |
| b.Func( |
| name, |
| utils::Vector{ |
| b.Param("v", T(ty)), |
| }, |
| T(ty), |
| utils::Vector{ |
| // var x = v; (unsigned) |
| // var x = select(U(v), ~U(v), v < 0); (signed) |
| b.Decl(b.Var("x", x)), |
| // let b16 = select(0, 16, bool(x & 0xffff0000)); |
| b.Decl(b.Let("b16", b.Call("select", V(0), V(16), B(b.And("x", V(0xffff0000)))))), |
| // x = x >> b16; |
| b.Assign("x", b.Shr("x", "b16")), |
| // let b8 = select(0, 8, bool(x & 0x0000ff00)); |
| b.Decl(b.Let("b8", b.Call("select", V(0), V(8), B(b.And("x", V(0x0000ff00)))))), |
| // x = x >> b8; |
| b.Assign("x", b.Shr("x", "b8")), |
| // let b4 = select(0, 4, bool(x & 0x000000f0)); |
| b.Decl(b.Let("b4", b.Call("select", V(0), V(4), B(b.And("x", V(0x000000f0)))))), |
| // x = x >> b4; |
| b.Assign("x", b.Shr("x", "b4")), |
| // let b2 = select(0, 2, bool(x & 0x0000000c)); |
| b.Decl(b.Let("b2", b.Call("select", V(0), V(2), B(b.And("x", V(0x0000000c)))))), |
| // x = x >> b2; |
| b.Assign("x", b.Shr("x", "b2")), |
| // let b1 = select(0, 1, bool(x & 0x00000002)); |
| b.Decl(b.Let("b1", b.Call("select", V(0), V(1), B(b.And("x", V(0x00000002)))))), |
| // let is_zero = select(0, 0xffffffff, x == 0); |
| b.Decl(b.Let("is_zero", b.Call("select", V(0), V(0xffffffff), b.Equal("x", V(0))))), |
| // return R(b16 | b8 | b4 | b2 | b1 | zero); |
| b.Return(b.Construct( |
| T(ty), b.Or(b.Or(b.Or(b.Or(b.Or("b16", "b8"), "b4"), "b2"), "b1"), "is_zero"))), |
| }); |
| return name; |
| } |
| |
| /// Builds the polyfill function for the `firstTrailingBit` builtin |
| /// @param ty the parameter and return type for the function |
| /// @return the polyfill function name |
| Symbol firstTrailingBit(const sem::Type* ty) { |
| auto name = b.Symbols().New("tint_first_trailing_bit"); |
| uint32_t width = WidthOf(ty); |
| |
| // Returns either u32 or vecN<u32> |
| auto U = [&]() -> const ast::Type* { |
| if (width == 1) { |
| return b.ty.u32(); |
| } |
| return b.ty.vec<u32>(width); |
| }; |
| auto V = [&](uint32_t value) -> const ast::Expression* { |
| return ScalarOrVector(width, u32(value)); |
| }; |
| auto B = [&](const ast::Expression* value) -> const ast::Expression* { |
| if (width == 1) { |
| return b.Construct<bool>(value); |
| } |
| return b.Construct(b.ty.vec<bool>(width), value); |
| }; |
| b.Func( |
| name, |
| utils::Vector{ |
| b.Param("v", T(ty)), |
| }, |
| T(ty), |
| utils::Vector{ |
| // var x = U(v); |
| b.Decl(b.Var("x", b.Construct(U(), b.Expr("v")))), |
| // let b16 = select(16, 0, bool(x & 0x0000ffff)); |
| b.Decl(b.Let("b16", b.Call("select", V(16), V(0), B(b.And("x", V(0x0000ffff)))))), |
| // x = x >> b16; |
| b.Assign("x", b.Shr("x", "b16")), |
| // let b8 = select(8, 0, bool(x & 0x000000ff)); |
| b.Decl(b.Let("b8", b.Call("select", V(8), V(0), B(b.And("x", V(0x000000ff)))))), |
| // x = x >> b8; |
| b.Assign("x", b.Shr("x", "b8")), |
| // let b4 = select(4, 0, bool(x & 0x0000000f)); |
| b.Decl(b.Let("b4", b.Call("select", V(4), V(0), B(b.And("x", V(0x0000000f)))))), |
| // x = x >> b4; |
| b.Assign("x", b.Shr("x", "b4")), |
| // let b2 = select(2, 0, bool(x & 0x00000003)); |
| b.Decl(b.Let("b2", b.Call("select", V(2), V(0), B(b.And("x", V(0x00000003)))))), |
| // x = x >> b2; |
| b.Assign("x", b.Shr("x", "b2")), |
| // let b1 = select(1, 0, bool(x & 0x00000001)); |
| b.Decl(b.Let("b1", b.Call("select", V(1), V(0), B(b.And("x", V(0x00000001)))))), |
| // let is_zero = select(0, 0xffffffff, x == 0); |
| b.Decl(b.Let("is_zero", b.Call("select", V(0), V(0xffffffff), b.Equal("x", V(0))))), |
| // return R(b16 | b8 | b4 | b2 | b1 | is_zero); |
| b.Return(b.Construct( |
| T(ty), b.Or(b.Or(b.Or(b.Or(b.Or("b16", "b8"), "b4"), "b2"), "b1"), "is_zero"))), |
| }); |
| return name; |
| } |
| |
| /// Builds the polyfill function for the `insertBits` builtin |
| /// @param ty the parameter and return type for the function |
| /// @return the polyfill function name |
| Symbol insertBits(const sem::Type* ty) { |
| auto name = b.Symbols().New("tint_insert_bits"); |
| uint32_t width = WidthOf(ty); |
| |
| // Currently in WGSL parameters of insertBits must be i32, u32, vecN<i32> or vecN<u32> |
| if (!sem::Type::DeepestElementOf(ty)->IsAnyOf<sem::I32, sem::U32>()) { |
| TINT_ICE(Transform, b.Diagnostics()) |
| << "insertBits polyfill only support i32, u32, and vector of i32 or u32, got " |
| << b.FriendlyName(ty); |
| return {}; |
| } |
| |
| constexpr uint32_t W = 32u; // 32-bit |
| |
| auto V = [&](auto value) -> const ast::Expression* { |
| const ast::Expression* expr = b.Expr(value); |
| if (!ty->is_unsigned_scalar_or_vector()) { |
| expr = b.Construct<i32>(expr); |
| } |
| if (ty->Is<sem::Vector>()) { |
| expr = b.Construct(T(ty), expr); |
| } |
| return expr; |
| }; |
| auto U = [&](auto value) -> const ast::Expression* { |
| if (width == 1) { |
| return b.Expr(value); |
| } |
| return b.vec(b.ty.u32(), width, value); |
| }; |
| |
| // Polyfill algorithm: |
| // s = min(offset, 32u); |
| // e = min(32u, (s + count)); |
| // mask = (((1u << s) - 1u) ^ ((1u << e) - 1u)); |
| // return (((n << s) & mask) | (v & ~(mask))); |
| // Note that the algorithm above use the left-shifting in C++ manner, but in WGSL, HLSL, MSL |
| // the rhs are modulo to bit-width of lhs (that is 32u in this case), and in GLSL the result |
| // is undefined if rhs is greater than or equal to bit-width of lhs. The results of `x << y` |
| // in C++ and HLSL are different when `y >= 32u`, and the `s` and `e` defined above can be |
| // 32u, which are cases we must handle specially. Replace all `(x << y)` to |
| // `select(Tx(), x << y, y < 32u)`, in which `Tx` is the type of x, where y can be greater |
| // than or equal to 32u. |
| // WGSL polyfill function: |
| // fn tint_insert_bits(v : T, n : T, offset : u32, count : u32) -> T { |
| // let e = offset + count; |
| // let mask = ( |
| // (select(0u, 1u << offset, offset < 32u) - 1u) ^ |
| // (select(0u, 1u << e, e < 32u) - 1u) |
| // ); |
| // return ((select(T(), n << offset, offset < 32u) & mask) | (v & ~(mask))); |
| // } |
| |
| utils::Vector<const ast::Statement*, 8> body; |
| |
| switch (polyfill.insert_bits) { |
| case Level::kFull: |
| // let e = offset + count; |
| body.Push(b.Decl(b.Let("e", b.Add("offset", "count")))); |
| |
| // let mask = ( |
| // (select(0u, 1u << offset, offset < 32u) - 1u) ^ |
| // (select(0u, 1u << e, e < 32u) - 1u) |
| // ); |
| body.Push(b.Decl(b.Let( |
| "mask", |
| b.Xor( // |
| b.Sub( |
| b.Call("select", 0_u, b.Shl(1_u, "offset"), b.LessThan("offset", 32_u)), |
| 1_u), |
| b.Sub(b.Call("select", 0_u, b.Shl(1_u, "e"), b.LessThan("e", 32_u)), |
| 1_u) // |
| )))); |
| |
| // return ((select(T(), n << offset, offset < 32u) & mask) | (v & ~(mask))); |
| body.Push( |
| b.Return(b.Or(b.And(b.Call("select", b.Construct(T(ty)), |
| b.Shl("n", U("offset")), b.LessThan("offset", 32_u)), |
| V("mask")), |
| b.And("v", V(b.Complement("mask")))))); |
| |
| break; |
| case Level::kClampParameters: |
| body.Push(b.Decl(b.Let("s", b.Call("min", "offset", u32(W))))); |
| body.Push(b.Decl(b.Let("e", b.Call("min", u32(W), b.Add("s", "count"))))); |
| body.Push(b.Return(b.Call("insertBits", "v", "n", "s", b.Sub("e", "s")))); |
| break; |
| default: |
| TINT_ICE(Transform, b.Diagnostics()) |
| << "unhandled polyfill level: " << static_cast<int>(polyfill.insert_bits); |
| return {}; |
| } |
| |
| b.Func(name, |
| utils::Vector{ |
| b.Param("v", T(ty)), |
| b.Param("n", T(ty)), |
| b.Param("offset", b.ty.u32()), |
| b.Param("count", b.ty.u32()), |
| }, |
| T(ty), body); |
| |
| return name; |
| } |
| |
| /// Builds the polyfill function for the `saturate` builtin |
| /// @param ty the parameter and return type for the function |
| /// @return the polyfill function name |
| Symbol saturate(const sem::Type* ty) { |
| auto name = b.Symbols().New("tint_saturate"); |
| auto body = utils::Vector{ |
| b.Return(b.Call("clamp", "v", b.Construct(T(ty), 0_a), b.Construct(T(ty), 1_a))), |
| }; |
| b.Func(name, |
| utils::Vector{ |
| b.Param("v", T(ty)), |
| }, |
| T(ty), body); |
| |
| return name; |
| } |
| |
| /// Builds the polyfill function for the `textureSampleBaseClampToEdge` builtin, when the |
| /// texture type is texture_2d<f32>. |
| /// @return the polyfill function name |
| Symbol textureSampleBaseClampToEdge_2d_f32() { |
| auto name = b.Symbols().New("tint_textureSampleBaseClampToEdge"); |
| auto body = utils::Vector{ |
| b.Decl(b.Let("dims", |
| b.Construct(b.ty.vec2<f32>(), b.Call("textureDimensions", "t", 0_a)))), |
| b.Decl(b.Let("half_texel", b.Div(b.vec2<f32>(0.5_a), "dims"))), |
| b.Decl( |
| b.Let("clamped", b.Call("clamp", "coord", "half_texel", b.Sub(1_a, "half_texel")))), |
| b.Return(b.Call("textureSampleLevel", "t", "s", "clamped", 0_a)), |
| }; |
| b.Func(name, |
| utils::Vector{ |
| b.Param("t", b.ty.sampled_texture(ast::TextureDimension::k2d, b.ty.f32())), |
| b.Param("s", b.ty.sampler(ast::SamplerKind::kSampler)), |
| b.Param("coord", b.ty.vec2<f32>()), |
| }, |
| b.ty.vec4<f32>(), body); |
| return name; |
| } |
| |
| /// Builds the polyfill function for the `quantizeToF16` builtin, by replacing the vector form |
| /// with scalar calls. |
| /// @param vec the vector type |
| /// @return the polyfill function name |
| Symbol quantizeToF16(const sem::Vector* vec) { |
| auto name = b.Symbols().New("tint_quantizeToF16"); |
| utils::Vector<const ast::Expression*, 4> args; |
| for (uint32_t i = 0; i < vec->Width(); i++) { |
| args.Push(b.Call("quantizeToF16", b.IndexAccessor("v", u32(i)))); |
| } |
| b.Func(name, |
| utils::Vector{ |
| b.Param("v", T(vec)), |
| }, |
| T(vec), |
| utils::Vector{ |
| b.Return(b.Construct(T(vec), std::move(args))), |
| }); |
| return name; |
| } |
| |
| //////////////////////////////////////////////////////////////////////////// |
| // Inline polyfills |
| //////////////////////////////////////////////////////////////////////////// |
| |
| /// Builds the polyfill inline expression for a bitshift left or bitshift right, ensuring that |
| /// the RHS is modulo the bit-width of the LHS. |
| /// @param bin_op the original BinaryExpression |
| /// @return the polyfill value for bitshift operation |
| const ast::Expression* BitshiftModulo(const ast::BinaryExpression* bin_op) { |
| auto* lhs_ty = ctx.src->TypeOf(bin_op->lhs)->UnwrapRef(); |
| auto* rhs_ty = ctx.src->TypeOf(bin_op->rhs)->UnwrapRef(); |
| auto* lhs_el_ty = sem::Type::DeepestElementOf(lhs_ty); |
| const ast::Expression* mask = b.Expr(AInt(lhs_el_ty->Size() * 8 - 1)); |
| if (rhs_ty->Is<sem::Vector>()) { |
| mask = b.Construct(CreateASTTypeFor(ctx, rhs_ty), mask); |
| } |
| auto* lhs = ctx.Clone(bin_op->lhs); |
| auto* rhs = b.And(ctx.Clone(bin_op->rhs), mask); |
| return b.create<ast::BinaryExpression>(ctx.Clone(bin_op->source), bin_op->op, lhs, rhs); |
| } |
| |
| /// Builds the polyfill inline expression for a integer divide or modulo, preventing DBZs and |
| /// integer overflows. |
| /// @param bin_op the original BinaryExpression |
| /// @return the polyfill divide or modulo |
| const ast::Expression* IntDivMod(const ast::BinaryExpression* bin_op) { |
| auto* lhs_ty = ctx.src->TypeOf(bin_op->lhs)->UnwrapRef(); |
| auto* rhs_ty = ctx.src->TypeOf(bin_op->rhs)->UnwrapRef(); |
| BinaryOpSignature sig{bin_op->op, lhs_ty, rhs_ty}; |
| auto fn = binary_op_polyfills.GetOrCreate(sig, [&] { |
| const bool is_div = bin_op->op == ast::BinaryOp::kDivide; |
| |
| uint32_t lhs_width = 1; |
| uint32_t rhs_width = 1; |
| const auto* lhs_el_ty = sem::Type::ElementOf(lhs_ty, &lhs_width); |
| const auto* rhs_el_ty = sem::Type::ElementOf(rhs_ty, &rhs_width); |
| |
| const uint32_t width = std::max(lhs_width, rhs_width); |
| |
| const char* lhs = "lhs"; |
| const char* rhs = "rhs"; |
| |
| utils::Vector<const ast::Statement*, 4> body; |
| |
| if (lhs_width < width) { |
| // lhs is scalar, rhs is vector. Convert lhs to vector. |
| body.Push(b.Decl(b.Let("l", b.vec(T(lhs_el_ty), width, b.Expr(lhs))))); |
| lhs = "l"; |
| } |
| if (rhs_width < width) { |
| // lhs is vector, rhs is scalar. Convert rhs to vector. |
| body.Push(b.Decl(b.Let("r", b.vec(T(rhs_el_ty), width, b.Expr(rhs))))); |
| rhs = "r"; |
| } |
| |
| auto name = b.Symbols().New(is_div ? "tint_div" : "tint_mod"); |
| auto* use_one = b.Equal(rhs, ScalarOrVector(width, 0_a)); |
| if (lhs_ty->is_signed_scalar_or_vector()) { |
| const auto bits = lhs_el_ty->Size() * 8; |
| auto min_int = AInt(AInt::kLowestValue >> (AInt::kNumBits - bits)); |
| const ast::Expression* lhs_is_min = b.Equal(lhs, ScalarOrVector(width, min_int)); |
| const ast::Expression* rhs_is_minus_one = b.Equal(rhs, ScalarOrVector(width, -1_a)); |
| // use_one = use_one | ((lhs == MIN_INT) & (rhs == -1)) |
| use_one = b.Or(use_one, b.And(lhs_is_min, rhs_is_minus_one)); |
| } |
| auto* select = b.Call("select", rhs, ScalarOrVector(width, 1_a), use_one); |
| |
| body.Push(b.Return(is_div ? b.Div(lhs, select) : b.Mod(lhs, select))); |
| b.Func(name, |
| utils::Vector{ |
| b.Param("lhs", T(lhs_ty)), |
| b.Param("rhs", T(rhs_ty)), |
| }, |
| width == 1 ? T(lhs_ty) : b.ty.vec(T(lhs_el_ty), width), // return type |
| std::move(body)); |
| |
| return name; |
| }); |
| auto* lhs = ctx.Clone(bin_op->lhs); |
| auto* rhs = ctx.Clone(bin_op->rhs); |
| return b.Call(fn, lhs, rhs); |
| } |
| |
| private: |
| /// The clone context |
| CloneContext& ctx; |
| /// The builtins to polyfill |
| Builtins polyfill; |
| /// The destination program builder |
| ProgramBuilder& b = *ctx.dst; |
| /// The source clone context |
| const sem::Info& sem = ctx.src->Sem(); |
| |
| // Polyfill functions for binary operators. |
| utils::Hashmap<BinaryOpSignature, Symbol, 8> binary_op_polyfills; |
| |
| /// @returns the AST type for the given sem type |
| const ast::Type* T(const sem::Type* ty) const { return CreateASTTypeFor(ctx, ty); } |
| |
| /// @returns 1 if `ty` is not a vector, otherwise the vector width |
| uint32_t WidthOf(const sem::Type* ty) const { |
| if (auto* v = ty->As<sem::Vector>()) { |
| return v->Width(); |
| } |
| return 1; |
| } |
| |
| /// @returns a scalar or vector with the given width, with each element with |
| /// the given value. |
| template <typename T> |
| const ast::Expression* ScalarOrVector(uint32_t width, T value) const { |
| if (width == 1) { |
| return b.Expr(value); |
| } |
| return b.Construct(b.ty.vec<T>(width), value); |
| } |
| }; |
| |
| BuiltinPolyfill::BuiltinPolyfill() = default; |
| |
| BuiltinPolyfill::~BuiltinPolyfill() = default; |
| |
| Transform::ApplyResult BuiltinPolyfill::Apply(const Program* src, |
| const DataMap& data, |
| DataMap&) const { |
| auto* cfg = data.Get<Config>(); |
| if (!cfg) { |
| return SkipTransform; |
| } |
| |
| auto& polyfill = cfg->builtins; |
| |
| utils::Hashmap<const sem::Builtin*, Symbol, 8> builtin_polyfills; |
| |
| ProgramBuilder b; |
| CloneContext ctx{&b, src, /* auto_clone_symbols */ true}; |
| State s{ctx, polyfill}; |
| |
| bool made_changes = false; |
| for (auto* node : src->ASTNodes().Objects()) { |
| auto* expr = src->Sem().Get<sem::Expression>(node); |
| if (!expr || expr->Stage() == sem::EvaluationStage::kConstant) { |
| continue; // Don't polyfill @const expressions |
| } |
| |
| if (auto* call = expr->As<sem::Call>()) { |
| auto* builtin = call->Target()->As<sem::Builtin>(); |
| if (!builtin) { |
| continue; |
| } |
| Symbol fn; |
| switch (builtin->Type()) { |
| case sem::BuiltinType::kAcosh: |
| if (polyfill.acosh != Level::kNone) { |
| fn = builtin_polyfills.GetOrCreate( |
| builtin, [&] { return s.acosh(builtin->ReturnType()); }); |
| } |
| break; |
| case sem::BuiltinType::kAsinh: |
| if (polyfill.asinh) { |
| fn = builtin_polyfills.GetOrCreate( |
| builtin, [&] { return s.asinh(builtin->ReturnType()); }); |
| } |
| break; |
| case sem::BuiltinType::kAtanh: |
| if (polyfill.atanh != Level::kNone) { |
| fn = builtin_polyfills.GetOrCreate( |
| builtin, [&] { return s.atanh(builtin->ReturnType()); }); |
| } |
| break; |
| case sem::BuiltinType::kClamp: |
| if (polyfill.clamp_int) { |
| auto& sig = builtin->Signature(); |
| if (sig.parameters[0]->Type()->is_integer_scalar_or_vector()) { |
| fn = builtin_polyfills.GetOrCreate( |
| builtin, [&] { return s.clampInteger(builtin->ReturnType()); }); |
| } |
| } |
| break; |
| case sem::BuiltinType::kCountLeadingZeros: |
| if (polyfill.count_leading_zeros) { |
| fn = builtin_polyfills.GetOrCreate( |
| builtin, [&] { return s.countLeadingZeros(builtin->ReturnType()); }); |
| } |
| break; |
| case sem::BuiltinType::kCountTrailingZeros: |
| if (polyfill.count_trailing_zeros) { |
| fn = builtin_polyfills.GetOrCreate( |
| builtin, [&] { return s.countTrailingZeros(builtin->ReturnType()); }); |
| } |
| break; |
| case sem::BuiltinType::kExtractBits: |
| if (polyfill.extract_bits != Level::kNone) { |
| fn = builtin_polyfills.GetOrCreate( |
| builtin, [&] { return s.extractBits(builtin->ReturnType()); }); |
| } |
| break; |
| case sem::BuiltinType::kFirstLeadingBit: |
| if (polyfill.first_leading_bit) { |
| fn = builtin_polyfills.GetOrCreate( |
| builtin, [&] { return s.firstLeadingBit(builtin->ReturnType()); }); |
| } |
| break; |
| case sem::BuiltinType::kFirstTrailingBit: |
| if (polyfill.first_trailing_bit) { |
| fn = builtin_polyfills.GetOrCreate( |
| builtin, [&] { return s.firstTrailingBit(builtin->ReturnType()); }); |
| } |
| break; |
| case sem::BuiltinType::kInsertBits: |
| if (polyfill.insert_bits != Level::kNone) { |
| fn = builtin_polyfills.GetOrCreate( |
| builtin, [&] { return s.insertBits(builtin->ReturnType()); }); |
| } |
| break; |
| case sem::BuiltinType::kSaturate: |
| if (polyfill.saturate) { |
| fn = builtin_polyfills.GetOrCreate( |
| builtin, [&] { return s.saturate(builtin->ReturnType()); }); |
| } |
| break; |
| case sem::BuiltinType::kTextureSampleBaseClampToEdge: |
| if (polyfill.texture_sample_base_clamp_to_edge_2d_f32) { |
| auto& sig = builtin->Signature(); |
| auto* tex = sig.Parameter(sem::ParameterUsage::kTexture); |
| if (auto* stex = tex->Type()->As<sem::SampledTexture>()) { |
| if (stex->type()->Is<sem::F32>()) { |
| fn = builtin_polyfills.GetOrCreate(builtin, [&] { |
| return s.textureSampleBaseClampToEdge_2d_f32(); |
| }); |
| } |
| } |
| } |
| break; |
| case sem::BuiltinType::kQuantizeToF16: |
| if (polyfill.quantize_to_vec_f16) { |
| if (auto* vec = builtin->ReturnType()->As<sem::Vector>()) { |
| fn = builtin_polyfills.GetOrCreate( |
| builtin, [&] { return s.quantizeToF16(vec); }); |
| } |
| } |
| break; |
| |
| default: |
| break; |
| } |
| |
| if (fn.IsValid()) { |
| auto* replacement = b.Call(fn, ctx.Clone(call->Declaration()->args)); |
| ctx.Replace(call->Declaration(), replacement); |
| made_changes = true; |
| } |
| } else if (auto* bin_op = node->As<ast::BinaryExpression>()) { |
| switch (bin_op->op) { |
| case ast::BinaryOp::kShiftLeft: |
| case ast::BinaryOp::kShiftRight: { |
| if (polyfill.bitshift_modulo) { |
| ctx.Replace(bin_op, [bin_op, &s] { return s.BitshiftModulo(bin_op); }); |
| made_changes = true; |
| } |
| break; |
| } |
| case ast::BinaryOp::kDivide: |
| case ast::BinaryOp::kModulo: { |
| if (polyfill.int_div_mod) { |
| auto* lhs_ty = src->TypeOf(bin_op->lhs)->UnwrapRef(); |
| if (lhs_ty->is_integer_scalar_or_vector()) { |
| ctx.Replace(bin_op, [bin_op, &s] { return s.IntDivMod(bin_op); }); |
| made_changes = true; |
| } |
| } |
| break; |
| } |
| default: |
| break; |
| } |
| } |
| } |
| |
| if (!made_changes) { |
| return SkipTransform; |
| } |
| |
| ctx.Clone(); |
| return Program(std::move(b)); |
| } |
| |
| BuiltinPolyfill::Config::Config(const Builtins& b) : builtins(b) {} |
| BuiltinPolyfill::Config::Config(const Config&) = default; |
| BuiltinPolyfill::Config::~Config() = default; |
| |
| } // namespace tint::transform |
