[llvm] [DirectX] Implement DXILResourceBindingAnalysis (PR #137258)

[Helena Kotas via llvm-commits]

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+//===- llvm/unittests/Target/DirectX/ResourceBindingAnalysisTests.cpp -----===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/Analysis/DXILResource.h"
+#include "llvm/AsmParser/Parser.h"
+#include "llvm/Passes/PassBuilder.h"
+#include "llvm/Support/DXILABI.h"
+#include "gtest/gtest.h"
+#include <cstdint>
+
+using namespace llvm;
+using namespace llvm::dxil;
+
+namespace {
+class ResourceBindingAnalysisTest : public testing::Test {
+protected:
+  PassBuilder *PB;
+  ModuleAnalysisManager *MAM;
+  LLVMContext *Context;
+
+  virtual void SetUp() {
+    PB = new PassBuilder();
+    MAM = new ModuleAnalysisManager();
+    Context = new LLVMContext();
+    PB->registerModuleAnalyses(*MAM);
+    MAM->registerPass([&] { return DXILResourceBindingAnalysis(); });
+  }
+
+  std::unique_ptr<Module> parseAsm(StringRef Asm) {
+    SMDiagnostic Error;
+    std::unique_ptr<Module> M = parseAssemblyString(Asm, Error, *Context);
+    EXPECT_TRUE(M) << "Bad assembly?: " << Error.getMessage();
+    return M;
+  }
+
+  virtual void TearDown() {
+    delete PB;
+    delete MAM;
+    delete Context;
+  }
+
+  void checkExpectedSpaceAndFreeRanges(
+      DXILResourceBindingInfo::RegisterSpace &RegSpace, uint32_t ExpSpace,
+      ArrayRef<uint32_t> ExpValues) {
+    EXPECT_EQ(RegSpace.Space, ExpSpace);
+    EXPECT_EQ(RegSpace.FreeRanges.size() * 2, ExpValues.size());
+    unsigned I = 0;
+    for (auto &R : RegSpace.FreeRanges) {
+      EXPECT_EQ(R.LowerBound, ExpValues[I]);
+      EXPECT_EQ(R.UpperBound, ExpValues[I + 1]);
+      I += 2;
+    }
+  }
+};
+
+TEST_F(ResourceBindingAnalysisTest, TestTrivialCase) {
+  // RWBuffer<float> Buf : register(u5);
+  StringRef Assembly = R"(
+define void @main() {
+entry:
+  %handle = call target("dx.TypedBuffer", float, 1, 0, 0) @llvm.dx.resource.handlefrombinding(i32 0, i32 5, i32 1, i32 0, i1 false)
+  ret void
+}
+  )";
+
+  auto M = parseAsm(Assembly);
+
+  DXILResourceBindingInfo &DRBI =
+      MAM->getResult<DXILResourceBindingAnalysis>(*M);
+
+  EXPECT_EQ(false, DRBI.hasImplicitBinding());
+  EXPECT_EQ(false, DRBI.hasOverlappingBinding());
+
+  // check that UAV has exactly one gap
+  DXILResourceBindingInfo::BindingSpaces &UAVSpaces =
+      DRBI.getBindingSpaces(ResourceClass::UAV);
+  EXPECT_EQ(UAVSpaces.ResClass, ResourceClass::UAV);
+  EXPECT_EQ(UAVSpaces.Spaces.size(), 1u);
+  checkExpectedSpaceAndFreeRanges(UAVSpaces.Spaces[0], 0,
+                                  {0, 4, 6, UINT32_MAX});
+
+  // check that other kinds of register spaces are all available
+  for (auto RC :
+       {ResourceClass::SRV, ResourceClass::CBuffer, ResourceClass::Sampler}) {
+    DXILResourceBindingInfo::BindingSpaces &Spaces = DRBI.getBindingSpaces(RC);
+    EXPECT_EQ(Spaces.ResClass, RC);
+    EXPECT_EQ(Spaces.Spaces.size(), 0u);
+  }
+}
+
+TEST_F(ResourceBindingAnalysisTest, TestManyBindings) {
+  // cbuffer CB                 : register(b3) { int a; }
+  // RWBuffer<float4> A[5]      : register(u10, space20);
+  // StructuredBuffer<int> B    : register(t5);
+  // RWBuffer<float> C          : register(u5);
+  // StructuredBuffer<int> D[5] : register(t0);
+  // RWBuffer<float> E[2]       : register(u2);
+  StringRef Assembly = R"(
+%__cblayout_CB = type <{ i32 }>
+define void @main() {
+entry:
+  %handleCB = call target("dx.CBuffer", target("dx.Layout", %__cblayout_CB, 4, 0)) @llvm.dx.resource.handlefrombinding(i32 0, i32 3, i32 1, i32 0, i1 false)
+  %handleA = call target("dx.TypedBuffer", float, 1, 0, 0) @llvm.dx.resource.handlefrombinding(i32 20, i32 10, i32 5, i32 0, i1 false)
+  %handleB = call target("dx.RawBuffer", i32, 0, 0) @llvm.dx.resource.handlefrombinding(i32 0, i32 5, i32 1, i32 0, i1 false)
+  %handleC = call target("dx.TypedBuffer", float, 1, 0, 0) @llvm.dx.resource.handlefrombinding(i32 0, i32 5, i32 1, i32 0, i1 false)
+  %handleD = call target("dx.RawBuffer", i32, 0, 0) @llvm.dx.resource.handlefrombinding(i32 0, i32 0, i32 5, i32 4, i1 false)
+  %handleE = call target("dx.TypedBuffer", float, 1, 0, 0) @llvm.dx.resource.handlefrombinding(i32 0, i32 2, i32 2, i32 0, i1 false)
+  ret void
+}
+  )";
+
+  auto M = parseAsm(Assembly);
+
+  DXILResourceBindingInfo &DRBI =
+      MAM->getResult<DXILResourceBindingAnalysis>(*M);
+
+  EXPECT_EQ(false, DRBI.hasImplicitBinding());
+  EXPECT_EQ(false, DRBI.hasOverlappingBinding());
+
+  DXILResourceBindingInfo::BindingSpaces &SRVSpaces =
+      DRBI.getBindingSpaces(ResourceClass::SRV);
+  EXPECT_EQ(SRVSpaces.ResClass, ResourceClass::SRV);
+  EXPECT_EQ(SRVSpaces.Spaces.size(), 1u);
+  checkExpectedSpaceAndFreeRanges(SRVSpaces.Spaces[0], 0, {6, UINT32_MAX});
+
+  DXILResourceBindingInfo::BindingSpaces &UAVSpaces =
+      DRBI.getBindingSpaces(ResourceClass::UAV);
+  EXPECT_EQ(UAVSpaces.ResClass, ResourceClass::UAV);
+  EXPECT_EQ(UAVSpaces.Spaces.size(), 2u);
+  checkExpectedSpaceAndFreeRanges(UAVSpaces.Spaces[0], 0,
+                                  {0, 1, 4, 4, 6, UINT32_MAX});
+  checkExpectedSpaceAndFreeRanges(UAVSpaces.Spaces[1], 20,
+                                  {0, 9, 15, UINT32_MAX});
+
+  DXILResourceBindingInfo::BindingSpaces &CBufferSpaces =
+      DRBI.getBindingSpaces(ResourceClass::CBuffer);
+  EXPECT_EQ(CBufferSpaces.ResClass, ResourceClass::CBuffer);
+  EXPECT_EQ(CBufferSpaces.Spaces.size(), 1u);
+  checkExpectedSpaceAndFreeRanges(CBufferSpaces.Spaces[0], 0,
+                                  {0, 2, 4, UINT32_MAX});
+}
+
+TEST_F(ResourceBindingAnalysisTest, TestUnboundedAndOverlap) {
----------------
hekota wrote:

I can add a test for exact overlap. For this PR it is will be XFAIL because we currently do not have a way to distinguish between 2 resources of the same type with identical binding. That will be addressed in https://github.com/llvm/llvm-project/issues/110723.

https://github.com/llvm/llvm-project/pull/137258