src/tint/lang/wgsl/ast/transform/simplify_pointers_test.cc - tint - Git at Google

 // Copyright 2021 The Dawn & Tint Authors
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are met:
 //
 // 1. Redistributions of source code must retain the above copyright notice, this
 //    list of conditions and the following disclaimer.
 //
 // 2. Redistributions in binary form must reproduce the above copyright notice,
 //    this list of conditions and the following disclaimer in the documentation
 //    and/or other materials provided with the distribution.
 //
 // 3. Neither the name of the copyright holder nor the names of its
 //    contributors may be used to endorse or promote products derived from
 //    this software without specific prior written permission.
 //
 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 // DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 // FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 // DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 // SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 // CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 // OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 #include "src/tint/lang/wgsl/ast/transform/simplify_pointers.h"

 #include "src/tint/lang/wgsl/ast/transform/helper_test.h"
 #include "src/tint/lang/wgsl/ast/transform/unshadow.h"

 namespace tint::ast::transform {
 namespace {

 using SimplifyPointersTest = TransformTest;

 TEST_F(SimplifyPointersTest, EmptyModule) {
     auto* src = "";

     EXPECT_FALSE(ShouldRun<SimplifyPointers>(src));
 }

 TEST_F(SimplifyPointersTest, FoldPointer) {
     auto* src = R"(
 fn f() {
   var v : i32;
   let p : ptr<function, i32> = &v;
   let x : i32 = *p;
 }
 )";

     auto* expect = R"(
 fn f() {
   var v : i32;
   let x : i32 = v;
 }
 )";

     auto got = Run<Unshadow, SimplifyPointers>(src);

     EXPECT_EQ(expect, str(got));
 }

 TEST_F(SimplifyPointersTest, UnusedPointerParam) {
     auto* src = R"(
 fn f(p : ptr<function, i32>) {
 }
 )";

     auto* expect = src;

     auto got = Run<Unshadow, SimplifyPointers>(src);

     EXPECT_EQ(expect, str(got));
 }

 TEST_F(SimplifyPointersTest, ReferencedPointerParam) {
     auto* src = R"(
 fn f(p : ptr<function, i32>) {
   let x = p;
 }
 )";

     auto* expect = R"(
 fn f(p : ptr<function, i32>) {
 }
 )";

     auto got = Run<Unshadow, SimplifyPointers>(src);

     EXPECT_EQ(expect, str(got));
 }

 TEST_F(SimplifyPointersTest, AddressOfDeref) {
     auto* src = R"(
 fn f() {
   var v : i32;
   let p : ptr<function, i32> = &(v);
   let x : ptr<function, i32> = &(*(p));
   let y : ptr<function, i32> = &(*(&(*(p))));
   let z : ptr<function, i32> = &(*(&(*(&(*(&(*(p))))))));
   var a = *x;
   var b = *y;
   var c = *z;
 }
 )";

     auto* expect = R"(
 fn f() {
   var v : i32;
   var a = v;
   var b = v;
   var c = v;
 }
 )";

     auto got = Run<Unshadow, SimplifyPointers>(src);

     EXPECT_EQ(expect, str(got));
 }

 TEST_F(SimplifyPointersTest, DerefAddressOf) {
     auto* src = R"(
 fn f() {
   var v : i32;
   let x : i32 = *(&(v));
   let y : i32 = *(&(*(&(v))));
   let z : i32 = *(&(*(&(*(&(*(&(v))))))));
 }
 )";

     auto* expect = R"(
 fn f() {
   var v : i32;
   let x : i32 = v;
   let y : i32 = v;
   let z : i32 = v;
 }
 )";

     auto got = Run<Unshadow, SimplifyPointers>(src);

     EXPECT_EQ(expect, str(got));
 }

 TEST_F(SimplifyPointersTest, PointerDerefIndex) {
     auto* src = R"(
 fn f() {
   var a : array<f32, 2>;
   let p = &a;
   let v = (*p)[1];
 }
 )";

     auto* expect = R"(
 fn f() {
   var a : array<f32, 2>;
   let v = a[1];
 }
 )";

     auto got = Run<Unshadow, SimplifyPointers>(src);

     EXPECT_EQ(expect, str(got));
 }

 TEST_F(SimplifyPointersTest, PointerIndex) {
     auto* src = R"(
 fn f() {
   var a : array<f32, 2>;
   let p = &a;
   let v = p[1];
 }
 )";

     auto* expect = R"(
 fn f() {
   var a : array<f32, 2>;
   let v = a[1];
 }
 )";

     auto got = Run<Unshadow, SimplifyPointers>(src);

     EXPECT_EQ(expect, str(got));
 }

 TEST_F(SimplifyPointersTest, SimpleChain) {
     auto* src = R"(
 fn f() {
   var a : array<f32, 2>;
   let ap : ptr<function, array<f32, 2>> = &a;
   let vp : ptr<function, f32> = &(*ap)[1];
   let v : f32 = *vp;
 }
 )";

     auto* expect = R"(
 fn f() {
   var a : array<f32, 2>;
   let v : f32 = a[1];
 }
 )";

     auto got = Run<Unshadow, SimplifyPointers>(src);

     EXPECT_EQ(expect, str(got));
 }

 TEST_F(SimplifyPointersTest, SimpleChain_ViaPointerIndex) {
     auto* src = R"(
 fn f() {
   var a : array<f32, 2>;
   let ap : ptr<function, array<f32, 2>> = &a;
   let vp : ptr<function, f32> = &ap[1];
   let v : f32 = *vp;
 }
 )";

     auto* expect = R"(
 fn f() {
   var a : array<f32, 2>;
   let v : f32 = a[1];
 }
 )";

     auto got = Run<Unshadow, SimplifyPointers>(src);

     EXPECT_EQ(expect, str(got));
 }

 TEST_F(SimplifyPointersTest, ComplexChain) {
     auto* src = R"(
 fn f() {
   var a : array<mat4x4<f32>, 4>;
   let ap : ptr<function, array<mat4x4<f32>, 4>> = &a;
   let mp : ptr<function, mat4x4<f32>> = &(*ap)[3];
   let vp : ptr<function, vec4<f32>> = &(*mp)[2];
   let v : vec4<f32> = *vp;
 }
 )";

     auto* expect = R"(
 fn f() {
   var a : array<mat4x4<f32>, 4>;
   let v : vec4<f32> = a[3][2];
 }
 )";

     auto got = Run<Unshadow, SimplifyPointers>(src);

     EXPECT_EQ(expect, str(got));
 }

 TEST_F(SimplifyPointersTest, ComplexChain_ViaPointerIndex) {
     auto* src = R"(
 fn f() {
   var a : array<mat4x4<f32>, 4>;
   let ap : ptr<function, array<mat4x4<f32>, 4>> = &a;
   let mp : ptr<function, mat4x4<f32>> = &ap[3];
   let vp : ptr<function, vec4<f32>> = &mp[2];
   let v : vec4<f32> = *vp;
 }
 )";

     auto* expect = R"(
 fn f() {
   var a : array<mat4x4<f32>, 4>;
   let v : vec4<f32> = a[3][2];
 }
 )";

     auto got = Run<Unshadow, SimplifyPointers>(src);

     EXPECT_EQ(expect, str(got));
 }

 TEST_F(SimplifyPointersTest, SavedVars) {
     auto* src = R"(
 struct S {
   i : i32,
 };

 fn arr() {
   var a : array<S, 2>;
   var i : i32 = 0;
   var j : i32 = 0;
   let p : ptr<function, i32> = &a[i + j].i;
   i = 2;
   *p = 4;
 }

 fn matrix() {
   var m : mat3x3<f32>;
   var i : i32 = 0;
   var j : i32 = 0;
   let p : ptr<function, vec3<f32>> = &m[i + j];
   i = 2;
   *p = vec3<f32>(4.0, 5.0, 6.0);
 }
 )";

     auto* expect = R"(
 struct S {
   i : i32,
 }

 fn arr() {
   var a : array<S, 2>;
   var i : i32 = 0;
   var j : i32 = 0;
   let p_save = (i + j);
   i = 2;
   a[p_save].i = 4;
 }

 fn matrix() {
   var m : mat3x3<f32>;
   var i : i32 = 0;
   var j : i32 = 0;
   let p_save_1 = (i + j);
   i = 2;
   m[p_save_1] = vec3<f32>(4.0, 5.0, 6.0);
 }
 )";

     auto got = Run<Unshadow, SimplifyPointers>(src);

     EXPECT_EQ(expect, str(got));
 }

 TEST_F(SimplifyPointersTest, DontSaveLiterals) {
     auto* src = R"(
 fn f() {
   var arr : array<i32, 2>;
   let p1 : ptr<function, i32> = &arr[1];
   *p1 = 4;
 }
 )";

     auto* expect = R"(
 fn f() {
   var arr : array<i32, 2>;
   arr[1] = 4;
 }
 )";

     auto got = Run<Unshadow, SimplifyPointers>(src);

     EXPECT_EQ(expect, str(got));
 }

 TEST_F(SimplifyPointersTest, SavedVarsChain) {
     auto* src = R"(
 fn f() {
   var arr : array<array<i32, 2>, 2>;
   let i : i32 = 0;
   let j : i32 = 1;
   let p : ptr<function, array<i32, 2>> = &arr[i];
   let q : ptr<function, i32> = &(*p)[j];
   *q = 12;
 }
 )";

     auto* expect = R"(
 fn f() {
   var arr : array<array<i32, 2>, 2>;
   let i : i32 = 0;
   let j : i32 = 1;
   let p_save = i;
   let q_save = j;
   arr[p_save][q_save] = 12;
 }
 )";

     auto got = Run<Unshadow, SimplifyPointers>(src);

     EXPECT_EQ(expect, str(got));
 }

 TEST_F(SimplifyPointersTest, ForLoopInit) {
     auto* src = R"(
 fn foo() -> i32 {
   return 1;
 }

 @fragment
 fn main() {
   var arr = array<f32, 4>();
   for (let a = &arr[foo()]; ;) {
     let x = *a;
     break;
   }
 }
 )";

     auto* expect = R"(
 fn foo() -> i32 {
   return 1;
 }

 @fragment
 fn main() {
   var arr = array<f32, 4>();
   let a_save = foo();
   for(; ; ) {
     let x = arr[a_save];
     break;
   }
 }
 )";

     auto got = Run<Unshadow, SimplifyPointers>(src);

     EXPECT_EQ(expect, str(got));
 }

 TEST_F(SimplifyPointersTest, MultiSavedVarsInSinglePtrLetExpr) {
     auto* src = R"(
 fn x() -> i32 {
   return 1;
 }

 fn y() -> i32 {
   return 1;
 }

 fn z() -> i32 {
   return 1;
 }

 struct Inner {
   a : array<i32, 2>,
 };

 struct Outer {
   a : array<Inner, 2>,
 };

 fn f() {
   var arr : array<Outer, 2>;
   let p : ptr<function, i32> = &arr[x()].a[y()].a[z()];
   *p = 1;
   *p = 2;
 }
 )";

     auto* expect = R"(
 fn x() -> i32 {
   return 1;
 }

 fn y() -> i32 {
   return 1;
 }

 fn z() -> i32 {
   return 1;
 }

 struct Inner {
   a : array<i32, 2>,
 }

 struct Outer {
   a : array<Inner, 2>,
 }

 fn f() {
   var arr : array<Outer, 2>;
   let p_save = x();
   let p_save_1 = y();
   let p_save_2 = z();
   arr[p_save].a[p_save_1].a[p_save_2] = 1;
   arr[p_save].a[p_save_1].a[p_save_2] = 2;
 }
 )";

     auto got = Run<Unshadow, SimplifyPointers>(src);

     EXPECT_EQ(expect, str(got));
 }

 TEST_F(SimplifyPointersTest, ShadowPointer) {
     auto* src = R"(
 var<private> a : array<i32, 2>;

 @compute @workgroup_size(1)
 fn main() {
   let x = &a;
   var a : i32 = (*x)[0];
   {
     var a : i32 = (*x)[1];
   }
 }
 )";

     auto* expect = R"(
 var<private> a : array<i32, 2>;

 @compute @workgroup_size(1)
 fn main() {
   var a_1 : i32 = a[0];
   {
     var a_2 : i32 = a[1];
   }
 }
 )";

     auto got = Run<Unshadow, SimplifyPointers>(src);

     EXPECT_EQ(expect, str(got));
 }

 }  // namespace
 }  // namespace tint::ast::transform
	// Copyright 2021 The Dawn & Tint Authors
	//
	// Redistribution and use in source and binary forms, with or without
	// modification, are permitted provided that the following conditions are met:
	//
	// 1. Redistributions of source code must retain the above copyright notice, this
	// list of conditions and the following disclaimer.
	//
	// 2. Redistributions in binary form must reproduce the above copyright notice,
	// this list of conditions and the following disclaimer in the documentation
	// and/or other materials provided with the distribution.
	//
	// 3. Neither the name of the copyright holder nor the names of its
	// contributors may be used to endorse or promote products derived from
	// this software without specific prior written permission.
	//
	// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
	// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
	// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
	// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
	// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
	// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
	// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

	#include "src/tint/lang/wgsl/ast/transform/simplify_pointers.h"

	#include "src/tint/lang/wgsl/ast/transform/helper_test.h"
	#include "src/tint/lang/wgsl/ast/transform/unshadow.h"

	namespace tint::ast::transform {
	namespace {

	using SimplifyPointersTest = TransformTest;

	TEST_F(SimplifyPointersTest, EmptyModule) {
	auto* src = "";

	EXPECT_FALSE(ShouldRun<SimplifyPointers>(src));
	}

	TEST_F(SimplifyPointersTest, FoldPointer) {
	auto* src = R"(
	fn f() {
	var v : i32;
	let p : ptr<function, i32> = &v;
	let x : i32 = *p;
	}
	)";

	auto* expect = R"(
	fn f() {
	var v : i32;
	let x : i32 = v;
	}
	)";

	auto got = Run<Unshadow, SimplifyPointers>(src);

	EXPECT_EQ(expect, str(got));
	}

	TEST_F(SimplifyPointersTest, UnusedPointerParam) {
	auto* src = R"(
	fn f(p : ptr<function, i32>) {
	}
	)";

	auto* expect = src;

	auto got = Run<Unshadow, SimplifyPointers>(src);

	EXPECT_EQ(expect, str(got));
	}

	TEST_F(SimplifyPointersTest, ReferencedPointerParam) {
	auto* src = R"(
	fn f(p : ptr<function, i32>) {
	let x = p;
	}
	)";

	auto* expect = R"(
	fn f(p : ptr<function, i32>) {
	}
	)";

	auto got = Run<Unshadow, SimplifyPointers>(src);

	EXPECT_EQ(expect, str(got));
	}

	TEST_F(SimplifyPointersTest, AddressOfDeref) {
	auto* src = R"(
	fn f() {
	var v : i32;
	let p : ptr<function, i32> = &(v);
	let x : ptr<function, i32> = &(*(p));
	let y : ptr<function, i32> = &((&((p))));
	let z : ptr<function, i32> = &((&((&((&((p))))))));
	var a = *x;
	var b = *y;
	var c = *z;
	}
	)";

	auto* expect = R"(
	fn f() {
	var v : i32;
	var a = v;
	var b = v;
	var c = v;
	}
	)";

	auto got = Run<Unshadow, SimplifyPointers>(src);

	EXPECT_EQ(expect, str(got));
	}

	TEST_F(SimplifyPointersTest, DerefAddressOf) {
	auto* src = R"(
	fn f() {
	var v : i32;
	let x : i32 = *(&(v));
	let y : i32 = (&((&(v))));
	let z : i32 = (&((&((&((&(v))))))));
	}
	)";

	auto* expect = R"(
	fn f() {
	var v : i32;
	let x : i32 = v;
	let y : i32 = v;
	let z : i32 = v;
	}
	)";

	auto got = Run<Unshadow, SimplifyPointers>(src);

	EXPECT_EQ(expect, str(got));
	}

	TEST_F(SimplifyPointersTest, PointerDerefIndex) {
	auto* src = R"(
	fn f() {
	var a : array<f32, 2>;
	let p = &a;
	let v = (*p)[1];
	}
	)";

	auto* expect = R"(
	fn f() {
	var a : array<f32, 2>;
	let v = a[1];
	}
	)";

	auto got = Run<Unshadow, SimplifyPointers>(src);

	EXPECT_EQ(expect, str(got));
	}

	TEST_F(SimplifyPointersTest, PointerIndex) {
	auto* src = R"(
	fn f() {
	var a : array<f32, 2>;
	let p = &a;
	let v = p[1];
	}
	)";

	auto* expect = R"(
	fn f() {
	var a : array<f32, 2>;
	let v = a[1];
	}
	)";

	auto got = Run<Unshadow, SimplifyPointers>(src);

	EXPECT_EQ(expect, str(got));
	}

	TEST_F(SimplifyPointersTest, SimpleChain) {
	auto* src = R"(
	fn f() {
	var a : array<f32, 2>;
	let ap : ptr<function, array<f32, 2>> = &a;
	let vp : ptr<function, f32> = &(*ap)[1];
	let v : f32 = *vp;
	}
	)";

	auto* expect = R"(
	fn f() {
	var a : array<f32, 2>;
	let v : f32 = a[1];
	}
	)";

	auto got = Run<Unshadow, SimplifyPointers>(src);

	EXPECT_EQ(expect, str(got));
	}

	TEST_F(SimplifyPointersTest, SimpleChain_ViaPointerIndex) {
	auto* src = R"(
	fn f() {
	var a : array<f32, 2>;
	let ap : ptr<function, array<f32, 2>> = &a;
	let vp : ptr<function, f32> = &ap[1];
	let v : f32 = *vp;
	}
	)";

	auto* expect = R"(
	fn f() {
	var a : array<f32, 2>;
	let v : f32 = a[1];
	}
	)";

	auto got = Run<Unshadow, SimplifyPointers>(src);

	EXPECT_EQ(expect, str(got));
	}

	TEST_F(SimplifyPointersTest, ComplexChain) {
	auto* src = R"(
	fn f() {
	var a : array<mat4x4<f32>, 4>;
	let ap : ptr<function, array<mat4x4<f32>, 4>> = &a;
	let mp : ptr<function, mat4x4<f32>> = &(*ap)[3];
	let vp : ptr<function, vec4<f32>> = &(*mp)[2];
	let v : vec4<f32> = *vp;
	}
	)";

	auto* expect = R"(
	fn f() {
	var a : array<mat4x4<f32>, 4>;
	let v : vec4<f32> = a[3][2];
	}
	)";

	auto got = Run<Unshadow, SimplifyPointers>(src);

	EXPECT_EQ(expect, str(got));
	}

	TEST_F(SimplifyPointersTest, ComplexChain_ViaPointerIndex) {
	auto* src = R"(
	fn f() {
	var a : array<mat4x4<f32>, 4>;
	let ap : ptr<function, array<mat4x4<f32>, 4>> = &a;
	let mp : ptr<function, mat4x4<f32>> = &ap[3];
	let vp : ptr<function, vec4<f32>> = &mp[2];
	let v : vec4<f32> = *vp;
	}
	)";

	auto* expect = R"(
	fn f() {
	var a : array<mat4x4<f32>, 4>;
	let v : vec4<f32> = a[3][2];
	}
	)";

	auto got = Run<Unshadow, SimplifyPointers>(src);

	EXPECT_EQ(expect, str(got));
	}

	TEST_F(SimplifyPointersTest, SavedVars) {
	auto* src = R"(
	struct S {
	i : i32,
	};

	fn arr() {
	var a : array<S, 2>;
	var i : i32 = 0;
	var j : i32 = 0;
	let p : ptr<function, i32> = &a[i + j].i;
	i = 2;
	*p = 4;
	}

	fn matrix() {
	var m : mat3x3<f32>;
	var i : i32 = 0;
	var j : i32 = 0;
	let p : ptr<function, vec3<f32>> = &m[i + j];
	i = 2;
	*p = vec3<f32>(4.0, 5.0, 6.0);
	}
	)";

	auto* expect = R"(
	struct S {
	i : i32,
	}

	fn arr() {
	var a : array<S, 2>;
	var i : i32 = 0;
	var j : i32 = 0;
	let p_save = (i + j);
	i = 2;
	a[p_save].i = 4;
	}

	fn matrix() {
	var m : mat3x3<f32>;
	var i : i32 = 0;
	var j : i32 = 0;
	let p_save_1 = (i + j);
	i = 2;
	m[p_save_1] = vec3<f32>(4.0, 5.0, 6.0);
	}
	)";

	auto got = Run<Unshadow, SimplifyPointers>(src);

	EXPECT_EQ(expect, str(got));
	}

	TEST_F(SimplifyPointersTest, DontSaveLiterals) {
	auto* src = R"(
	fn f() {
	var arr : array<i32, 2>;
	let p1 : ptr<function, i32> = &arr[1];
	*p1 = 4;
	}
	)";

	auto* expect = R"(
	fn f() {
	var arr : array<i32, 2>;
	arr[1] = 4;
	}
	)";

	auto got = Run<Unshadow, SimplifyPointers>(src);

	EXPECT_EQ(expect, str(got));
	}

	TEST_F(SimplifyPointersTest, SavedVarsChain) {
	auto* src = R"(
	fn f() {
	var arr : array<array<i32, 2>, 2>;
	let i : i32 = 0;
	let j : i32 = 1;
	let p : ptr<function, array<i32, 2>> = &arr[i];
	let q : ptr<function, i32> = &(*p)[j];
	*q = 12;
	}
	)";

	auto* expect = R"(
	fn f() {
	var arr : array<array<i32, 2>, 2>;
	let i : i32 = 0;
	let j : i32 = 1;
	let p_save = i;
	let q_save = j;
	arr[p_save][q_save] = 12;
	}
	)";

	auto got = Run<Unshadow, SimplifyPointers>(src);

	EXPECT_EQ(expect, str(got));
	}

	TEST_F(SimplifyPointersTest, ForLoopInit) {
	auto* src = R"(
	fn foo() -> i32 {
	return 1;
	}

	@fragment
	fn main() {
	var arr = array<f32, 4>();
	for (let a = &arr[foo()]; ;) {
	let x = *a;
	break;
	}
	}
	)";

	auto* expect = R"(
	fn foo() -> i32 {
	return 1;
	}

	@fragment
	fn main() {
	var arr = array<f32, 4>();
	let a_save = foo();
	for(; ; ) {
	let x = arr[a_save];
	break;
	}
	}
	)";

	auto got = Run<Unshadow, SimplifyPointers>(src);

	EXPECT_EQ(expect, str(got));
	}

	TEST_F(SimplifyPointersTest, MultiSavedVarsInSinglePtrLetExpr) {
	auto* src = R"(
	fn x() -> i32 {
	return 1;
	}

	fn y() -> i32 {
	return 1;
	}

	fn z() -> i32 {
	return 1;
	}

	struct Inner {
	a : array<i32, 2>,
	};

	struct Outer {
	a : array<Inner, 2>,
	};

	fn f() {
	var arr : array<Outer, 2>;
	let p : ptr<function, i32> = &arr[x()].a[y()].a[z()];
	*p = 1;
	*p = 2;
	}
	)";

	auto* expect = R"(
	fn x() -> i32 {
	return 1;
	}

	fn y() -> i32 {
	return 1;
	}

	fn z() -> i32 {
	return 1;
	}

	struct Inner {
	a : array<i32, 2>,
	}

	struct Outer {
	a : array<Inner, 2>,
	}

	fn f() {
	var arr : array<Outer, 2>;
	let p_save = x();
	let p_save_1 = y();
	let p_save_2 = z();
	arr[p_save].a[p_save_1].a[p_save_2] = 1;
	arr[p_save].a[p_save_1].a[p_save_2] = 2;
	}
	)";

	auto got = Run<Unshadow, SimplifyPointers>(src);

	EXPECT_EQ(expect, str(got));
	}

	TEST_F(SimplifyPointersTest, ShadowPointer) {
	auto* src = R"(
	var<private> a : array<i32, 2>;

	@compute @workgroup_size(1)
	fn main() {
	let x = &a;
	var a : i32 = (*x)[0];
	{
	var a : i32 = (*x)[1];
	}
	}
	)";

	auto* expect = R"(
	var<private> a : array<i32, 2>;

	@compute @workgroup_size(1)
	fn main() {
	var a_1 : i32 = a[0];
	{
	var a_2 : i32 = a[1];
	}
	}
	)";

	auto got = Run<Unshadow, SimplifyPointers>(src);

	EXPECT_EQ(expect, str(got));
	}

	} // namespace
	} // namespace tint::ast::transform