tint: const eval of reverseBits

Bug: tint:1581
Change-Id: I3dd1ea2c774f9fc0dff87b71f25375a469c3d05e
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/108300
Reviewed-by: Dan Sinclair <dsinclair@chromium.org>
Commit-Queue: Antonio Maiorano <amaiorano@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>

src/tint/intrinsics.def

@@ -520,8 +520,8 @@ fn radians<T: f32_f16>(T) -> T
 fn radians<N: num, T: f32_f16>(vec<N, T>) -> vec<N, T>
 fn reflect<N: num, T: f32_f16>(vec<N, T>, vec<N, T>) -> vec<N, T>
 fn refract<N: num, T: f32_f16>(vec<N, T>, vec<N, T>, T) -> vec<N, T>
-fn reverseBits<T: iu32>(T) -> T
+@const fn reverseBits<T: iu32>(T) -> T
-fn reverseBits<N: num, T: iu32>(vec<N, T>) -> vec<N, T>
+@const fn reverseBits<N: num, T: iu32>(vec<N, T>) -> vec<N, T>
 fn round<T: f32_f16>(T) -> T
 fn round<N: num, T: f32_f16>(vec<N, T>) -> vec<N, T>
 @const fn saturate<T: fa_f32_f16>(@test_value(2) T) -> T

src/tint/resolver/const_eval.cc

@@ -1822,7 +1822,7 @@ ConstEval::Result ConstEval::extractBits(const sem::Type* ty,
                     // Only need to set other bits if bit at c - 1 of result is 1
                     if ((r & (UT{1} << (c - UT{1}))) != UT{0}) {
                         UT dst_mask = src_mask >> o;
-                        r = r | (~UT{0} & ~dst_mask);
+                        r |= (~UT{0} & ~dst_mask);
                     }
                 }
 
@@ -1956,9 +1956,9 @@ ConstEval::Result ConstEval::insertBits(const sem::Type* ty,
                 // newbits. Other bits of the result are copied from e.
                 UT from = newbits << o;
                 UT mask = ((UT{1} << c) - UT{1}) << UT{o};
-                auto r = e;             // Start with 'e' as the result
+                auto r = e;          // Start with 'e' as the result
-                r = r & ~mask;          // Zero the bits in 'e' we're overwriting
+                r &= ~mask;          // Zero the bits in 'e' we're overwriting
-                r = r | (from & mask);  // Overwrite from 'newbits' (shifted into position)
+                r |= (from & mask);  // Overwrite from 'newbits' (shifted into position)
                 result = NumberT{r};
             }
 
@@ -1969,6 +1969,33 @@ ConstEval::Result ConstEval::insertBits(const sem::Type* ty,
     return TransformElements(builder, ty, transform, args[0], args[1]);
 }
 
+ConstEval::Result ConstEval::reverseBits(const sem::Type* ty,
+                                         utils::VectorRef<const sem::Constant*> args,
+                                         const Source&) {
+    auto transform = [&](const sem::Constant* c0) {
+        auto create = [&](auto in_e) -> ImplResult {
+            using NumberT = decltype(in_e);
+            using T = UnwrapNumber<NumberT>;
+            using UT = std::make_unsigned_t<T>;
+            constexpr UT kNumBits = sizeof(UT) * 8;
+
+            UT e = static_cast<UT>(in_e);
+            UT r = UT{0};
+            for (size_t s = 0; s < kNumBits; ++s) {
+                // Write source 's' bit to destination 'd' bit if 1
+                if (e & (UT{1} << s)) {
+                    size_t d = kNumBits - s - 1;
+                    r |= (UT{1} << d);
+                }
+            }
+
+            return CreateElement(builder, c0->Type(), NumberT{r});
+        };
+        return Dispatch_iu32(create, c0);
+    };
+    return TransformElements(builder, ty, transform, args[0]);
+}
+
 ConstEval::Result ConstEval::saturate(const sem::Type* ty,
                                       utils::VectorRef<const sem::Constant*> args,
                                       const Source&) {

src/tint/resolver/const_eval.h

@@ -509,8 +509,8 @@ class ConstEval {
     /// @param source the source location of the conversion
     /// @return the result value, or null if the value cannot be calculated
     Result extractBits(const sem::Type* ty,
-        utils::VectorRef<const sem::Constant*> args,
+                       utils::VectorRef<const sem::Constant*> args,
-        const Source& source);
+                       const Source& source);
 
     /// firstLeadingBit builtin
     /// @param ty the expression type
@@ -548,6 +548,15 @@ class ConstEval {
                       utils::VectorRef<const sem::Constant*> args,
                       const Source& source);
 
+    /// reverseBits builtin
+    /// @param ty the expression type
+    /// @param args the input arguments
+    /// @param source the source location of the conversion
+    /// @return the result value, or null if the value cannot be calculated
+    Result reverseBits(const sem::Type* ty,
+                       utils::VectorRef<const sem::Constant*> args,
+                       const Source& source);
+
     /// saturate builtin
     /// @param ty the expression type
     /// @param args the input arguments

src/tint/resolver/const_eval_builtin_test.cc

@@ -1106,6 +1106,52 @@ INSTANTIATE_TEST_SUITE_P(ExtractBits,
                              std::make_tuple(1000, 1000),         //
                              std::make_tuple(u32::Highest(), u32::Highest())));
 
+template <typename T>
+std::vector<Case> ReverseBitsCases() {
+    using B = BitValues<T>;
+    return {
+        C({T(0)}, T(0)),
+
+        C({B::Lsh(1, 0)}, B::Lsh(1, 31)),  //
+        C({B::Lsh(1, 1)}, B::Lsh(1, 30)),  //
+        C({B::Lsh(1, 2)}, B::Lsh(1, 29)),  //
+        C({B::Lsh(1, 3)}, B::Lsh(1, 28)),  //
+        C({B::Lsh(1, 4)}, B::Lsh(1, 27)),  //
+        //...
+        C({B::Lsh(1, 27)}, B::Lsh(1, 4)),  //
+        C({B::Lsh(1, 28)}, B::Lsh(1, 3)),  //
+        C({B::Lsh(1, 29)}, B::Lsh(1, 2)),  //
+        C({B::Lsh(1, 30)}, B::Lsh(1, 1)),  //
+        C({B::Lsh(1, 31)}, B::Lsh(1, 0)),  //
+
+        C({/**/ T(0b00010001000100010000000000000000)},
+          /* */ T(0b00000000000000001000100010001000)),
+
+        C({/**/ T(0b00011000000110000000000000000000)},
+          /* */ T(0b00000000000000000001100000011000)),
+
+        C({/**/ T(0b00000100000000001111111111111111)},
+          /* */ T(0b11111111111111110000000000100000)),
+
+        C({/**/ T(0b10010101111000110000011111101010)},
+          /* */ T(0b01010111111000001100011110101001)),
+
+        // Vector tests
+        C({/**/ Vec(T(0b00010001000100010000000000000000),  //
+                    T(0b00011000000110000000000000000000),  //
+                    T(0b00000000000000001111111111111111))},
+          /* */ Vec(T(0b00000000000000001000100010001000),  //
+                    T(0b00000000000000000001100000011000),  //
+                    T(0b11111111111111110000000000000000))),
+    };
+}
+INSTANTIATE_TEST_SUITE_P(  //
+    ReverseBits,
+    ResolverConstEvalBuiltinTest,
+    testing::Combine(testing::Values(sem::BuiltinType::kReverseBits),
+                     testing::ValuesIn(Concat(ReverseBitsCases<i32>(),  //
+                                              ReverseBitsCases<u32>()))));
+
 template <typename T>
 std::vector<Case> SaturateCases() {
     return {

src/tint/resolver/intrinsic_table.inl

@@ -12398,7 +12398,7 @@ constexpr OverloadInfo kOverloads[] = {
     /* parameters */ &kParameters[869],
     /* return matcher indices */ &kMatcherIndices[1],
     /* flags */ OverloadFlags(OverloadFlag::kIsBuiltin, OverloadFlag::kSupportsVertexPipeline, OverloadFlag::kSupportsFragmentPipeline, OverloadFlag::kSupportsComputePipeline),
-    /* const eval */ nullptr,
+    /* const eval */ &ConstEval::reverseBits,
   },
   {
     /* [339] */
@@ -12410,7 +12410,7 @@ constexpr OverloadInfo kOverloads[] = {
     /* parameters */ &kParameters[868],
     /* return matcher indices */ &kMatcherIndices[30],
     /* flags */ OverloadFlags(OverloadFlag::kIsBuiltin, OverloadFlag::kSupportsVertexPipeline, OverloadFlag::kSupportsFragmentPipeline, OverloadFlag::kSupportsComputePipeline),
-    /* const eval */ nullptr,
+    /* const eval */ &ConstEval::reverseBits,
   },
   {
     /* [340] */

test/tint/builtins/gen/literal/reverseBits/222177.wgsl.expected.dxc.hlsl

@@ -1,5 +1,5 @@
 void reverseBits_222177() {
-  int2 res = asint(reversebits(asuint((1).xx)));
+  int2 res = (-2147483648).xx;
 }
 
 struct tint_symbol {

test/tint/builtins/gen/literal/reverseBits/222177.wgsl.expected.fxc.hlsl

@@ -1,5 +1,5 @@
 void reverseBits_222177() {
-  int2 res = asint(reversebits(asuint((1).xx)));
+  int2 res = (-2147483648).xx;
 }
 
 struct tint_symbol {

test/tint/builtins/gen/literal/reverseBits/222177.wgsl.expected.glsl

@@ -1,7 +1,7 @@
 #version 310 es
 
 void reverseBits_222177() {
-  ivec2 res = bitfieldReverse(ivec2(1));
+  ivec2 res = ivec2(-2147483648);
 }
 
 vec4 vertex_main() {
@@ -21,7 +21,7 @@ void main() {
 precision mediump float;
 
 void reverseBits_222177() {
-  ivec2 res = bitfieldReverse(ivec2(1));
+  ivec2 res = ivec2(-2147483648);
 }
 
 void fragment_main() {
@@ -35,7 +35,7 @@ void main() {
 #version 310 es
 
 void reverseBits_222177() {
-  ivec2 res = bitfieldReverse(ivec2(1));
+  ivec2 res = ivec2(-2147483648);
 }
 
 void compute_main() {

test/tint/builtins/gen/literal/reverseBits/222177.wgsl.expected.msl

@@ -2,7 +2,7 @@
 
 using namespace metal;
 void reverseBits_222177() {
-  int2 res = reverse_bits(int2(1));
+  int2 res = int2((-2147483647 - 1));
 }
 
 struct tint_symbol {

test/tint/builtins/gen/literal/reverseBits/222177.wgsl.expected.spvasm

@@ -1,7 +1,7 @@
 ; SPIR-V
 ; Version: 1.3
 ; Generator: Google Tint Compiler; 0
-; Bound: 35
+; Bound: 34
 ; Schema: 0
                OpCapability Shader
                OpMemoryModel Logical GLSL450
@@ -32,38 +32,37 @@
           %9 = OpTypeFunction %void
         %int = OpTypeInt 32 1
       %v2int = OpTypeVector %int 2
-      %int_1 = OpConstant %int 1
+%int_n2147483648 = OpConstant %int -2147483648
-         %17 = OpConstantComposite %v2int %int_1 %int_1
+         %16 = OpConstantComposite %v2int %int_n2147483648 %int_n2147483648
 %_ptr_Function_v2int = OpTypePointer Function %v2int
-         %20 = OpConstantNull %v2int
+         %19 = OpConstantNull %v2int
-         %21 = OpTypeFunction %v4float
+         %20 = OpTypeFunction %v4float
     %float_1 = OpConstant %float 1
 %reverseBits_222177 = OpFunction %void None %9
          %12 = OpLabel
-        %res = OpVariable %_ptr_Function_v2int Function %20
+        %res = OpVariable %_ptr_Function_v2int Function %19
-         %13 = OpBitReverse %v2int %17
+               OpStore %res %16
-               OpStore %res %13
                OpReturn
                OpFunctionEnd
-%vertex_main_inner = OpFunction %v4float None %21
+%vertex_main_inner = OpFunction %v4float None %20
-         %23 = OpLabel
+         %22 = OpLabel
-         %24 = OpFunctionCall %void %reverseBits_222177
+         %23 = OpFunctionCall %void %reverseBits_222177
                OpReturnValue %5
                OpFunctionEnd
 %vertex_main = OpFunction %void None %9
-         %26 = OpLabel
+         %25 = OpLabel
-         %27 = OpFunctionCall %v4float %vertex_main_inner
+         %26 = OpFunctionCall %v4float %vertex_main_inner
-               OpStore %value %27
+               OpStore %value %26
                OpStore %vertex_point_size %float_1
                OpReturn
                OpFunctionEnd
 %fragment_main = OpFunction %void None %9
-         %30 = OpLabel
+         %29 = OpLabel
-         %31 = OpFunctionCall %void %reverseBits_222177
+         %30 = OpFunctionCall %void %reverseBits_222177
                OpReturn
                OpFunctionEnd
 %compute_main = OpFunction %void None %9
-         %33 = OpLabel
+         %32 = OpLabel
-         %34 = OpFunctionCall %void %reverseBits_222177
+         %33 = OpFunctionCall %void %reverseBits_222177
                OpReturn
                OpFunctionEnd

test/tint/builtins/gen/literal/reverseBits/35fea9.wgsl.expected.dxc.hlsl

@@ -1,5 +1,5 @@
 void reverseBits_35fea9() {
-  uint4 res = reversebits((1u).xxxx);
+  uint4 res = (2147483648u).xxxx;
 }
 
 struct tint_symbol {

test/tint/builtins/gen/literal/reverseBits/35fea9.wgsl.expected.fxc.hlsl

@@ -1,5 +1,5 @@
 void reverseBits_35fea9() {
-  uint4 res = reversebits((1u).xxxx);
+  uint4 res = (2147483648u).xxxx;
 }
 
 struct tint_symbol {

test/tint/builtins/gen/literal/reverseBits/35fea9.wgsl.expected.glsl

@@ -1,7 +1,7 @@
 #version 310 es
 
 void reverseBits_35fea9() {
-  uvec4 res = bitfieldReverse(uvec4(1u));
+  uvec4 res = uvec4(2147483648u);
 }
 
 vec4 vertex_main() {
@@ -21,7 +21,7 @@ void main() {
 precision mediump float;
 
 void reverseBits_35fea9() {
-  uvec4 res = bitfieldReverse(uvec4(1u));
+  uvec4 res = uvec4(2147483648u);
 }
 
 void fragment_main() {
@@ -35,7 +35,7 @@ void main() {
 #version 310 es
 
 void reverseBits_35fea9() {
-  uvec4 res = bitfieldReverse(uvec4(1u));
+  uvec4 res = uvec4(2147483648u);
 }
 
 void compute_main() {

test/tint/builtins/gen/literal/reverseBits/35fea9.wgsl.expected.msl

@@ -2,7 +2,7 @@
 
 using namespace metal;
 void reverseBits_35fea9() {
-  uint4 res = reverse_bits(uint4(1u));
+  uint4 res = uint4(2147483648u);
 }
 
 struct tint_symbol {

test/tint/builtins/gen/literal/reverseBits/35fea9.wgsl.expected.spvasm

@@ -1,7 +1,7 @@
 ; SPIR-V
 ; Version: 1.3
 ; Generator: Google Tint Compiler; 0
-; Bound: 35
+; Bound: 34
 ; Schema: 0
                OpCapability Shader
                OpMemoryModel Logical GLSL450
@@ -32,38 +32,37 @@
           %9 = OpTypeFunction %void
        %uint = OpTypeInt 32 0
      %v4uint = OpTypeVector %uint 4
-     %uint_1 = OpConstant %uint 1
+%uint_2147483648 = OpConstant %uint 2147483648
-         %17 = OpConstantComposite %v4uint %uint_1 %uint_1 %uint_1 %uint_1
+         %16 = OpConstantComposite %v4uint %uint_2147483648 %uint_2147483648 %uint_2147483648 %uint_2147483648
 %_ptr_Function_v4uint = OpTypePointer Function %v4uint
-         %20 = OpConstantNull %v4uint
+         %19 = OpConstantNull %v4uint
-         %21 = OpTypeFunction %v4float
+         %20 = OpTypeFunction %v4float
     %float_1 = OpConstant %float 1
 %reverseBits_35fea9 = OpFunction %void None %9
          %12 = OpLabel
-        %res = OpVariable %_ptr_Function_v4uint Function %20
+        %res = OpVariable %_ptr_Function_v4uint Function %19
-         %13 = OpBitReverse %v4uint %17
+               OpStore %res %16
-               OpStore %res %13
                OpReturn
                OpFunctionEnd
-%vertex_main_inner = OpFunction %v4float None %21
+%vertex_main_inner = OpFunction %v4float None %20
-         %23 = OpLabel
+         %22 = OpLabel
-         %24 = OpFunctionCall %void %reverseBits_35fea9
+         %23 = OpFunctionCall %void %reverseBits_35fea9
                OpReturnValue %5
                OpFunctionEnd
 %vertex_main = OpFunction %void None %9
-         %26 = OpLabel
+         %25 = OpLabel
-         %27 = OpFunctionCall %v4float %vertex_main_inner
+         %26 = OpFunctionCall %v4float %vertex_main_inner
-               OpStore %value %27
+               OpStore %value %26
                OpStore %vertex_point_size %float_1
                OpReturn
                OpFunctionEnd
 %fragment_main = OpFunction %void None %9
-         %30 = OpLabel
+         %29 = OpLabel
-         %31 = OpFunctionCall %void %reverseBits_35fea9
+         %30 = OpFunctionCall %void %reverseBits_35fea9
                OpReturn
                OpFunctionEnd
 %compute_main = OpFunction %void None %9
-         %33 = OpLabel
+         %32 = OpLabel
-         %34 = OpFunctionCall %void %reverseBits_35fea9
+         %33 = OpFunctionCall %void %reverseBits_35fea9
                OpReturn
                OpFunctionEnd

test/tint/builtins/gen/literal/reverseBits/4dbd6f.wgsl.expected.dxc.hlsl

@@ -1,5 +1,5 @@
 void reverseBits_4dbd6f() {
-  int4 res = asint(reversebits(asuint((1).xxxx)));
+  int4 res = (-2147483648).xxxx;
 }
 
 struct tint_symbol {

test/tint/builtins/gen/literal/reverseBits/4dbd6f.wgsl.expected.fxc.hlsl

@@ -1,5 +1,5 @@
 void reverseBits_4dbd6f() {
-  int4 res = asint(reversebits(asuint((1).xxxx)));
+  int4 res = (-2147483648).xxxx;
 }
 
 struct tint_symbol {

test/tint/builtins/gen/literal/reverseBits/4dbd6f.wgsl.expected.glsl

@@ -1,7 +1,7 @@
 #version 310 es
 
 void reverseBits_4dbd6f() {
-  ivec4 res = bitfieldReverse(ivec4(1));
+  ivec4 res = ivec4(-2147483648);
 }
 
 vec4 vertex_main() {
@@ -21,7 +21,7 @@ void main() {
 precision mediump float;
 
 void reverseBits_4dbd6f() {
-  ivec4 res = bitfieldReverse(ivec4(1));
+  ivec4 res = ivec4(-2147483648);
 }
 
 void fragment_main() {
@@ -35,7 +35,7 @@ void main() {
 #version 310 es
 
 void reverseBits_4dbd6f() {
-  ivec4 res = bitfieldReverse(ivec4(1));
+  ivec4 res = ivec4(-2147483648);
 }
 
 void compute_main() {

test/tint/builtins/gen/literal/reverseBits/4dbd6f.wgsl.expected.msl

@@ -2,7 +2,7 @@
 
 using namespace metal;
 void reverseBits_4dbd6f() {
-  int4 res = reverse_bits(int4(1));
+  int4 res = int4((-2147483647 - 1));
 }
 
 struct tint_symbol {

test/tint/builtins/gen/literal/reverseBits/4dbd6f.wgsl.expected.spvasm

@@ -1,7 +1,7 @@
 ; SPIR-V
 ; Version: 1.3
 ; Generator: Google Tint Compiler; 0
-; Bound: 35
+; Bound: 34
 ; Schema: 0
                OpCapability Shader
                OpMemoryModel Logical GLSL450
@@ -32,38 +32,37 @@
           %9 = OpTypeFunction %void
         %int = OpTypeInt 32 1
       %v4int = OpTypeVector %int 4
-      %int_1 = OpConstant %int 1
+%int_n2147483648 = OpConstant %int -2147483648
-         %17 = OpConstantComposite %v4int %int_1 %int_1 %int_1 %int_1
+         %16 = OpConstantComposite %v4int %int_n2147483648 %int_n2147483648 %int_n2147483648 %int_n2147483648
 %_ptr_Function_v4int = OpTypePointer Function %v4int
-         %20 = OpConstantNull %v4int
+         %19 = OpConstantNull %v4int
-         %21 = OpTypeFunction %v4float
+         %20 = OpTypeFunction %v4float
     %float_1 = OpConstant %float 1
 %reverseBits_4dbd6f = OpFunction %void None %9
          %12 = OpLabel
-        %res = OpVariable %_ptr_Function_v4int Function %20
+        %res = OpVariable %_ptr_Function_v4int Function %19
-         %13 = OpBitReverse %v4int %17
+               OpStore %res %16
-               OpStore %res %13
                OpReturn
                OpFunctionEnd
-%vertex_main_inner = OpFunction %v4float None %21
+%vertex_main_inner = OpFunction %v4float None %20
-         %23 = OpLabel
+         %22 = OpLabel
-         %24 = OpFunctionCall %void %reverseBits_4dbd6f
+         %23 = OpFunctionCall %void %reverseBits_4dbd6f
                OpReturnValue %5
                OpFunctionEnd
 %vertex_main = OpFunction %void None %9
-         %26 = OpLabel
+         %25 = OpLabel
-         %27 = OpFunctionCall %v4float %vertex_main_inner
+         %26 = OpFunctionCall %v4float %vertex_main_inner
-               OpStore %value %27
+               OpStore %value %26
                OpStore %vertex_point_size %float_1
                OpReturn
                OpFunctionEnd
 %fragment_main = OpFunction %void None %9
-         %30 = OpLabel
+         %29 = OpLabel
-         %31 = OpFunctionCall %void %reverseBits_4dbd6f
+         %30 = OpFunctionCall %void %reverseBits_4dbd6f
                OpReturn
                OpFunctionEnd
 %compute_main = OpFunction %void None %9
-         %33 = OpLabel
+         %32 = OpLabel
-         %34 = OpFunctionCall %void %reverseBits_4dbd6f
+         %33 = OpFunctionCall %void %reverseBits_4dbd6f
                OpReturn
                OpFunctionEnd

test/tint/builtins/gen/literal/reverseBits/7c4269.wgsl.expected.dxc.hlsl

@@ -1,5 +1,5 @@
 void reverseBits_7c4269() {
-  int res = asint(reversebits(asuint(1)));
+  int res = -2147483648;
 }
 
 struct tint_symbol {

test/tint/builtins/gen/literal/reverseBits/7c4269.wgsl.expected.fxc.hlsl

@@ -1,5 +1,5 @@
 void reverseBits_7c4269() {
-  int res = asint(reversebits(asuint(1)));
+  int res = -2147483648;
 }
 
 struct tint_symbol {

test/tint/builtins/gen/literal/reverseBits/7c4269.wgsl.expected.glsl

@@ -1,7 +1,7 @@
 #version 310 es
 
 void reverseBits_7c4269() {
-  int res = bitfieldReverse(1);
+  int res = -2147483648;
 }
 
 vec4 vertex_main() {
@@ -21,7 +21,7 @@ void main() {
 precision mediump float;
 
 void reverseBits_7c4269() {
-  int res = bitfieldReverse(1);
+  int res = -2147483648;
 }
 
 void fragment_main() {
@@ -35,7 +35,7 @@ void main() {
 #version 310 es
 
 void reverseBits_7c4269() {
-  int res = bitfieldReverse(1);
+  int res = -2147483648;
 }
 
 void compute_main() {

test/tint/builtins/gen/literal/reverseBits/7c4269.wgsl.expected.msl

@@ -2,7 +2,7 @@
 
 using namespace metal;
 void reverseBits_7c4269() {
-  int res = reverse_bits(1);
+  int res = (-2147483647 - 1);
 }
 
 struct tint_symbol {

test/tint/builtins/gen/literal/reverseBits/7c4269.wgsl.expected.spvasm

@@ -1,7 +1,7 @@
 ; SPIR-V
 ; Version: 1.3
 ; Generator: Google Tint Compiler; 0
-; Bound: 33
+; Bound: 32
 ; Schema: 0
                OpCapability Shader
                OpMemoryModel Logical GLSL450
@@ -31,37 +31,36 @@
        %void = OpTypeVoid
           %9 = OpTypeFunction %void
         %int = OpTypeInt 32 1
-      %int_1 = OpConstant %int 1
+%int_n2147483648 = OpConstant %int -2147483648
 %_ptr_Function_int = OpTypePointer Function %int
-         %18 = OpConstantNull %int
+         %17 = OpConstantNull %int
-         %19 = OpTypeFunction %v4float
+         %18 = OpTypeFunction %v4float
     %float_1 = OpConstant %float 1
 %reverseBits_7c4269 = OpFunction %void None %9
          %12 = OpLabel
-        %res = OpVariable %_ptr_Function_int Function %18
+        %res = OpVariable %_ptr_Function_int Function %17
-         %13 = OpBitReverse %int %int_1
+               OpStore %res %int_n2147483648
-               OpStore %res %13
                OpReturn
                OpFunctionEnd
-%vertex_main_inner = OpFunction %v4float None %19
+%vertex_main_inner = OpFunction %v4float None %18
-         %21 = OpLabel
+         %20 = OpLabel
-         %22 = OpFunctionCall %void %reverseBits_7c4269
+         %21 = OpFunctionCall %void %reverseBits_7c4269
                OpReturnValue %5
                OpFunctionEnd
 %vertex_main = OpFunction %void None %9
-         %24 = OpLabel
+         %23 = OpLabel
-         %25 = OpFunctionCall %v4float %vertex_main_inner
+         %24 = OpFunctionCall %v4float %vertex_main_inner
-               OpStore %value %25
+               OpStore %value %24
                OpStore %vertex_point_size %float_1
                OpReturn
                OpFunctionEnd
 %fragment_main = OpFunction %void None %9
-         %28 = OpLabel
+         %27 = OpLabel
-         %29 = OpFunctionCall %void %reverseBits_7c4269
+         %28 = OpFunctionCall %void %reverseBits_7c4269
                OpReturn
                OpFunctionEnd
 %compute_main = OpFunction %void None %9
-         %31 = OpLabel
+         %30 = OpLabel
-         %32 = OpFunctionCall %void %reverseBits_7c4269
+         %31 = OpFunctionCall %void %reverseBits_7c4269
                OpReturn
                OpFunctionEnd

test/tint/builtins/gen/literal/reverseBits/a6ccd4.wgsl.expected.dxc.hlsl

@@ -1,5 +1,5 @@
 void reverseBits_a6ccd4() {
-  uint3 res = reversebits((1u).xxx);
+  uint3 res = (2147483648u).xxx;
 }
 
 struct tint_symbol {

test/tint/builtins/gen/literal/reverseBits/a6ccd4.wgsl.expected.fxc.hlsl

@@ -1,5 +1,5 @@
 void reverseBits_a6ccd4() {
-  uint3 res = reversebits((1u).xxx);
+  uint3 res = (2147483648u).xxx;
 }
 
 struct tint_symbol {

test/tint/builtins/gen/literal/reverseBits/a6ccd4.wgsl.expected.glsl

@@ -1,7 +1,7 @@
 #version 310 es
 
 void reverseBits_a6ccd4() {
-  uvec3 res = bitfieldReverse(uvec3(1u));
+  uvec3 res = uvec3(2147483648u);
 }
 
 vec4 vertex_main() {
@@ -21,7 +21,7 @@ void main() {
 precision mediump float;
 
 void reverseBits_a6ccd4() {
-  uvec3 res = bitfieldReverse(uvec3(1u));
+  uvec3 res = uvec3(2147483648u);
 }
 
 void fragment_main() {
@@ -35,7 +35,7 @@ void main() {
 #version 310 es
 
 void reverseBits_a6ccd4() {
-  uvec3 res = bitfieldReverse(uvec3(1u));
+  uvec3 res = uvec3(2147483648u);
 }
 
 void compute_main() {

test/tint/builtins/gen/literal/reverseBits/a6ccd4.wgsl.expected.msl

@@ -2,7 +2,7 @@
 
 using namespace metal;
 void reverseBits_a6ccd4() {
-  uint3 res = reverse_bits(uint3(1u));
+  uint3 res = uint3(2147483648u);
 }
 
 struct tint_symbol {

test/tint/builtins/gen/literal/reverseBits/a6ccd4.wgsl.expected.spvasm

@@ -1,7 +1,7 @@
 ; SPIR-V
 ; Version: 1.3
 ; Generator: Google Tint Compiler; 0
-; Bound: 35
+; Bound: 34
 ; Schema: 0
                OpCapability Shader
                OpMemoryModel Logical GLSL450
@@ -32,38 +32,37 @@
           %9 = OpTypeFunction %void
        %uint = OpTypeInt 32 0
      %v3uint = OpTypeVector %uint 3
-     %uint_1 = OpConstant %uint 1
+%uint_2147483648 = OpConstant %uint 2147483648
-         %17 = OpConstantComposite %v3uint %uint_1 %uint_1 %uint_1
+         %16 = OpConstantComposite %v3uint %uint_2147483648 %uint_2147483648 %uint_2147483648
 %_ptr_Function_v3uint = OpTypePointer Function %v3uint
-         %20 = OpConstantNull %v3uint
+         %19 = OpConstantNull %v3uint
-         %21 = OpTypeFunction %v4float
+         %20 = OpTypeFunction %v4float
     %float_1 = OpConstant %float 1
 %reverseBits_a6ccd4 = OpFunction %void None %9
          %12 = OpLabel
-        %res = OpVariable %_ptr_Function_v3uint Function %20
+        %res = OpVariable %_ptr_Function_v3uint Function %19
-         %13 = OpBitReverse %v3uint %17
+               OpStore %res %16
-               OpStore %res %13
                OpReturn
                OpFunctionEnd
-%vertex_main_inner = OpFunction %v4float None %21
+%vertex_main_inner = OpFunction %v4float None %20
-         %23 = OpLabel
+         %22 = OpLabel
-         %24 = OpFunctionCall %void %reverseBits_a6ccd4
+         %23 = OpFunctionCall %void %reverseBits_a6ccd4
                OpReturnValue %5
                OpFunctionEnd
 %vertex_main = OpFunction %void None %9
-         %26 = OpLabel
+         %25 = OpLabel
-         %27 = OpFunctionCall %v4float %vertex_main_inner
+         %26 = OpFunctionCall %v4float %vertex_main_inner
-               OpStore %value %27
+               OpStore %value %26
                OpStore %vertex_point_size %float_1
                OpReturn
                OpFunctionEnd
 %fragment_main = OpFunction %void None %9
-         %30 = OpLabel
+         %29 = OpLabel
-         %31 = OpFunctionCall %void %reverseBits_a6ccd4
+         %30 = OpFunctionCall %void %reverseBits_a6ccd4
                OpReturn
                OpFunctionEnd
 %compute_main = OpFunction %void None %9
-         %33 = OpLabel
+         %32 = OpLabel
-         %34 = OpFunctionCall %void %reverseBits_a6ccd4
+         %33 = OpFunctionCall %void %reverseBits_a6ccd4
                OpReturn
                OpFunctionEnd

test/tint/builtins/gen/literal/reverseBits/c21bc1.wgsl.expected.dxc.hlsl

@@ -1,5 +1,5 @@
 void reverseBits_c21bc1() {
-  int3 res = asint(reversebits(asuint((1).xxx)));
+  int3 res = (-2147483648).xxx;
 }
 
 struct tint_symbol {

test/tint/builtins/gen/literal/reverseBits/c21bc1.wgsl.expected.fxc.hlsl

@@ -1,5 +1,5 @@
 void reverseBits_c21bc1() {
-  int3 res = asint(reversebits(asuint((1).xxx)));
+  int3 res = (-2147483648).xxx;
 }
 
 struct tint_symbol {

test/tint/builtins/gen/literal/reverseBits/c21bc1.wgsl.expected.glsl

@@ -1,7 +1,7 @@
 #version 310 es
 
 void reverseBits_c21bc1() {
-  ivec3 res = bitfieldReverse(ivec3(1));
+  ivec3 res = ivec3(-2147483648);
 }
 
 vec4 vertex_main() {
@@ -21,7 +21,7 @@ void main() {
 precision mediump float;
 
 void reverseBits_c21bc1() {
-  ivec3 res = bitfieldReverse(ivec3(1));
+  ivec3 res = ivec3(-2147483648);
 }
 
 void fragment_main() {
@@ -35,7 +35,7 @@ void main() {
 #version 310 es
 
 void reverseBits_c21bc1() {
-  ivec3 res = bitfieldReverse(ivec3(1));
+  ivec3 res = ivec3(-2147483648);
 }
 
 void compute_main() {

test/tint/builtins/gen/literal/reverseBits/c21bc1.wgsl.expected.msl

@@ -2,7 +2,7 @@
 
 using namespace metal;
 void reverseBits_c21bc1() {
-  int3 res = reverse_bits(int3(1));
+  int3 res = int3((-2147483647 - 1));
 }
 
 struct tint_symbol {

test/tint/builtins/gen/literal/reverseBits/c21bc1.wgsl.expected.spvasm

@@ -1,7 +1,7 @@
 ; SPIR-V
 ; Version: 1.3
 ; Generator: Google Tint Compiler; 0
-; Bound: 35
+; Bound: 34
 ; Schema: 0
                OpCapability Shader
                OpMemoryModel Logical GLSL450
@@ -32,38 +32,37 @@
           %9 = OpTypeFunction %void
         %int = OpTypeInt 32 1
       %v3int = OpTypeVector %int 3
-      %int_1 = OpConstant %int 1
+%int_n2147483648 = OpConstant %int -2147483648
-         %17 = OpConstantComposite %v3int %int_1 %int_1 %int_1
+         %16 = OpConstantComposite %v3int %int_n2147483648 %int_n2147483648 %int_n2147483648
 %_ptr_Function_v3int = OpTypePointer Function %v3int
-         %20 = OpConstantNull %v3int
+         %19 = OpConstantNull %v3int
-         %21 = OpTypeFunction %v4float
+         %20 = OpTypeFunction %v4float
     %float_1 = OpConstant %float 1
 %reverseBits_c21bc1 = OpFunction %void None %9
          %12 = OpLabel
-        %res = OpVariable %_ptr_Function_v3int Function %20
+        %res = OpVariable %_ptr_Function_v3int Function %19
-         %13 = OpBitReverse %v3int %17
+               OpStore %res %16
-               OpStore %res %13
                OpReturn
                OpFunctionEnd
-%vertex_main_inner = OpFunction %v4float None %21
+%vertex_main_inner = OpFunction %v4float None %20
-         %23 = OpLabel
+         %22 = OpLabel
-         %24 = OpFunctionCall %void %reverseBits_c21bc1
+         %23 = OpFunctionCall %void %reverseBits_c21bc1
                OpReturnValue %5
                OpFunctionEnd
 %vertex_main = OpFunction %void None %9
-         %26 = OpLabel
+         %25 = OpLabel
-         %27 = OpFunctionCall %v4float %vertex_main_inner
+         %26 = OpFunctionCall %v4float %vertex_main_inner
-               OpStore %value %27
+               OpStore %value %26
                OpStore %vertex_point_size %float_1
                OpReturn
                OpFunctionEnd
 %fragment_main = OpFunction %void None %9
-         %30 = OpLabel
+         %29 = OpLabel
-         %31 = OpFunctionCall %void %reverseBits_c21bc1
+         %30 = OpFunctionCall %void %reverseBits_c21bc1
                OpReturn
                OpFunctionEnd
 %compute_main = OpFunction %void None %9
-         %33 = OpLabel
+         %32 = OpLabel
-         %34 = OpFunctionCall %void %reverseBits_c21bc1
+         %33 = OpFunctionCall %void %reverseBits_c21bc1
                OpReturn
                OpFunctionEnd

test/tint/builtins/gen/literal/reverseBits/e1f4c1.wgsl.expected.dxc.hlsl

@@ -1,5 +1,5 @@
 void reverseBits_e1f4c1() {
-  uint2 res = reversebits((1u).xx);
+  uint2 res = (2147483648u).xx;
 }
 
 struct tint_symbol {

test/tint/builtins/gen/literal/reverseBits/e1f4c1.wgsl.expected.fxc.hlsl

@@ -1,5 +1,5 @@
 void reverseBits_e1f4c1() {
-  uint2 res = reversebits((1u).xx);
+  uint2 res = (2147483648u).xx;
 }
 
 struct tint_symbol {

test/tint/builtins/gen/literal/reverseBits/e1f4c1.wgsl.expected.glsl

@@ -1,7 +1,7 @@
 #version 310 es
 
 void reverseBits_e1f4c1() {
-  uvec2 res = bitfieldReverse(uvec2(1u));
+  uvec2 res = uvec2(2147483648u);
 }
 
 vec4 vertex_main() {
@@ -21,7 +21,7 @@ void main() {
 precision mediump float;
 
 void reverseBits_e1f4c1() {
-  uvec2 res = bitfieldReverse(uvec2(1u));
+  uvec2 res = uvec2(2147483648u);
 }
 
 void fragment_main() {
@@ -35,7 +35,7 @@ void main() {
 #version 310 es
 
 void reverseBits_e1f4c1() {
-  uvec2 res = bitfieldReverse(uvec2(1u));
+  uvec2 res = uvec2(2147483648u);
 }
 
 void compute_main() {

test/tint/builtins/gen/literal/reverseBits/e1f4c1.wgsl.expected.msl

@@ -2,7 +2,7 @@
 
 using namespace metal;
 void reverseBits_e1f4c1() {
-  uint2 res = reverse_bits(uint2(1u));
+  uint2 res = uint2(2147483648u);
 }
 
 struct tint_symbol {

test/tint/builtins/gen/literal/reverseBits/e1f4c1.wgsl.expected.spvasm

@@ -1,7 +1,7 @@
 ; SPIR-V
 ; Version: 1.3
 ; Generator: Google Tint Compiler; 0
-; Bound: 35
+; Bound: 34
 ; Schema: 0
                OpCapability Shader
                OpMemoryModel Logical GLSL450
@@ -32,38 +32,37 @@
           %9 = OpTypeFunction %void
        %uint = OpTypeInt 32 0
      %v2uint = OpTypeVector %uint 2
-     %uint_1 = OpConstant %uint 1
+%uint_2147483648 = OpConstant %uint 2147483648
-         %17 = OpConstantComposite %v2uint %uint_1 %uint_1
+         %16 = OpConstantComposite %v2uint %uint_2147483648 %uint_2147483648
 %_ptr_Function_v2uint = OpTypePointer Function %v2uint
-         %20 = OpConstantNull %v2uint
+         %19 = OpConstantNull %v2uint
-         %21 = OpTypeFunction %v4float
+         %20 = OpTypeFunction %v4float
     %float_1 = OpConstant %float 1
 %reverseBits_e1f4c1 = OpFunction %void None %9
          %12 = OpLabel
-        %res = OpVariable %_ptr_Function_v2uint Function %20
+        %res = OpVariable %_ptr_Function_v2uint Function %19
-         %13 = OpBitReverse %v2uint %17
+               OpStore %res %16
-               OpStore %res %13
                OpReturn
                OpFunctionEnd
-%vertex_main_inner = OpFunction %v4float None %21
+%vertex_main_inner = OpFunction %v4float None %20
-         %23 = OpLabel
+         %22 = OpLabel
-         %24 = OpFunctionCall %void %reverseBits_e1f4c1
+         %23 = OpFunctionCall %void %reverseBits_e1f4c1
                OpReturnValue %5
                OpFunctionEnd
 %vertex_main = OpFunction %void None %9
-         %26 = OpLabel
+         %25 = OpLabel
-         %27 = OpFunctionCall %v4float %vertex_main_inner
+         %26 = OpFunctionCall %v4float %vertex_main_inner
-               OpStore %value %27
+               OpStore %value %26
                OpStore %vertex_point_size %float_1
                OpReturn
                OpFunctionEnd
 %fragment_main = OpFunction %void None %9
-         %30 = OpLabel
+         %29 = OpLabel
-         %31 = OpFunctionCall %void %reverseBits_e1f4c1
+         %30 = OpFunctionCall %void %reverseBits_e1f4c1
                OpReturn
                OpFunctionEnd
 %compute_main = OpFunction %void None %9
-         %33 = OpLabel
+         %32 = OpLabel
-         %34 = OpFunctionCall %void %reverseBits_e1f4c1
+         %33 = OpFunctionCall %void %reverseBits_e1f4c1
                OpReturn
                OpFunctionEnd

test/tint/builtins/gen/literal/reverseBits/e31adf.wgsl.expected.dxc.hlsl

@@ -1,5 +1,5 @@
 void reverseBits_e31adf() {
-  uint res = reversebits(1u);
+  uint res = 2147483648u;
 }
 
 struct tint_symbol {

test/tint/builtins/gen/literal/reverseBits/e31adf.wgsl.expected.fxc.hlsl

@@ -1,5 +1,5 @@
 void reverseBits_e31adf() {
-  uint res = reversebits(1u);
+  uint res = 2147483648u;
 }
 
 struct tint_symbol {

test/tint/builtins/gen/literal/reverseBits/e31adf.wgsl.expected.glsl

@@ -1,7 +1,7 @@
 #version 310 es
 
 void reverseBits_e31adf() {
-  uint res = bitfieldReverse(1u);
+  uint res = 2147483648u;
 }
 
 vec4 vertex_main() {
@@ -21,7 +21,7 @@ void main() {
 precision mediump float;
 
 void reverseBits_e31adf() {
-  uint res = bitfieldReverse(1u);
+  uint res = 2147483648u;
 }
 
 void fragment_main() {
@@ -35,7 +35,7 @@ void main() {
 #version 310 es
 
 void reverseBits_e31adf() {
-  uint res = bitfieldReverse(1u);
+  uint res = 2147483648u;
 }
 
 void compute_main() {

test/tint/builtins/gen/literal/reverseBits/e31adf.wgsl.expected.msl

@@ -2,7 +2,7 @@
 
 using namespace metal;
 void reverseBits_e31adf() {
-  uint res = reverse_bits(1u);
+  uint res = 2147483648u;
 }
 
 struct tint_symbol {

test/tint/builtins/gen/literal/reverseBits/e31adf.wgsl.expected.spvasm

@@ -1,7 +1,7 @@
 ; SPIR-V
 ; Version: 1.3
 ; Generator: Google Tint Compiler; 0
-; Bound: 33
+; Bound: 32
 ; Schema: 0
                OpCapability Shader
                OpMemoryModel Logical GLSL450
@@ -31,37 +31,36 @@
        %void = OpTypeVoid
           %9 = OpTypeFunction %void
        %uint = OpTypeInt 32 0
-     %uint_1 = OpConstant %uint 1
+%uint_2147483648 = OpConstant %uint 2147483648
 %_ptr_Function_uint = OpTypePointer Function %uint
-         %18 = OpConstantNull %uint
+         %17 = OpConstantNull %uint
-         %19 = OpTypeFunction %v4float
+         %18 = OpTypeFunction %v4float
     %float_1 = OpConstant %float 1
 %reverseBits_e31adf = OpFunction %void None %9
          %12 = OpLabel
-        %res = OpVariable %_ptr_Function_uint Function %18
+        %res = OpVariable %_ptr_Function_uint Function %17
-         %13 = OpBitReverse %uint %uint_1
+               OpStore %res %uint_2147483648
-               OpStore %res %13
                OpReturn
                OpFunctionEnd
-%vertex_main_inner = OpFunction %v4float None %19
+%vertex_main_inner = OpFunction %v4float None %18
-         %21 = OpLabel
+         %20 = OpLabel
-         %22 = OpFunctionCall %void %reverseBits_e31adf
+         %21 = OpFunctionCall %void %reverseBits_e31adf
                OpReturnValue %5
                OpFunctionEnd
 %vertex_main = OpFunction %void None %9
-         %24 = OpLabel
+         %23 = OpLabel
-         %25 = OpFunctionCall %v4float %vertex_main_inner
+         %24 = OpFunctionCall %v4float %vertex_main_inner
-               OpStore %value %25
+               OpStore %value %24
                OpStore %vertex_point_size %float_1
                OpReturn
                OpFunctionEnd
 %fragment_main = OpFunction %void None %9
-         %28 = OpLabel
+         %27 = OpLabel
-         %29 = OpFunctionCall %void %reverseBits_e31adf
+         %28 = OpFunctionCall %void %reverseBits_e31adf
                OpReturn
                OpFunctionEnd
 %compute_main = OpFunction %void None %9
-         %31 = OpLabel
+         %30 = OpLabel
-         %32 = OpFunctionCall %void %reverseBits_e31adf
+         %31 = OpFunctionCall %void %reverseBits_e31adf
                OpReturn
                OpFunctionEnd