[CodeGen] Complete register allocation infrastructure

1 files changed, 92 insertions, 0 deletions

diff --git a/backend/unittests/CodeGen/LiveRegMatrixTest.cpp b/backend/unittests/CodeGen/LiveRegMatrixTest.cpp
new file mode 100644
index 0000000..21c0778
--- /dev/null
+++ b/backend/unittests/CodeGen/LiveRegMatrixTest.cpp
@@ -0,0 +1,92 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include "rcc/CodeGen/LiveRegMatrix.h"
+
+#include "CodeGen/RegisterAllocationTestSupport.h"
+
+#include <algorithm>
+#include <iostream>
+
+namespace {
+
+using namespace rcc;
+using namespace rcc::test;
+using namespace rcc::test::ra;
+
+void testLaneAndAssignment(TestContext &Context, const TargetDescription &Target) {
+  auto Fixture = createFunction("matrix-lanes", 1);
+  if (!Fixture)
+    return;
+  auto Low = createVReg(*Fixture->Function);
+  auto High = createVReg(*Fixture->Function);
+  if (!Low || !High ||
+      !buildDef(*Fixture->Function, Target, *Fixture->Block, *Low, 1, TestSubReg::Low32) ||
+      !buildDef(*Fixture->Function, Target, *Fixture->Block, *High, 2, TestSubReg::High32) ||
+      !buildUse(*Fixture->Function, Target, *Fixture->Block, *High, TestSubReg::High32) ||
+      !buildUse(*Fixture->Function, Target, *Fixture->Block, *Low, TestSubReg::Low32))
+    return;
+
+  MachineAnalysisManager Analyses;
+  if (!registerStage11MachineAnalyses(Analyses))
+    return;
+  auto Intervals = Analyses.getResult<LiveIntervalsAnalysis>(*Fixture->Function, Target);
+  if (!Intervals)
+    return;
+  const PhysicalRegister G0 = physical(TestRegister::G0);
+  LiveRegMatrix Matrix(*Fixture->Function, Target, **Intervals);
+  Context.expect(Matrix.assign(*Low, G0).has_value() &&
+                     Matrix.checkInterference(*High, G0).Kind == RegisterInterferenceKind::Free &&
+                     Matrix.assign(*High, G0).has_value() && Matrix.assignment(*Low) == G0,
+                 "LiveRegMatrix must allow disjoint lanes and publish assignments");
+  Context.expect(Matrix.unassign(*Low).has_value() && !Matrix.assignment(*Low),
+                 "LiveRegMatrix must remove an assignment without affecting other lanes");
+}
+
+void testFixedAndMaskInterference(TestContext &Context, const TargetDescription &Target) {
+  auto Fixture = createFunction("matrix-fixed", 2);
+  if (!Fixture)
+    return;
+  auto Value = createVReg(*Fixture->Function);
+  const PhysicalRegister G0 = physical(TestRegister::G0);
+  const PhysicalRegister G1 = physical(TestRegister::G1);
+  if (!Value || !buildDef(*Fixture->Function, Target, *Fixture->Block, *Value, 7) ||
+      !buildMask(*Fixture->Function, Target, *Fixture->Block, createTestCallPreservedMask()) ||
+      !buildUse(*Fixture->Function, Target, *Fixture->Block, Register::fromPhysical(G0)) ||
+      !buildUse(*Fixture->Function, Target, *Fixture->Block, *Value))
+    return;
+
+  MachineAnalysisManager Analyses;
+  if (!registerStage11MachineAnalyses(Analyses))
+    return;
+  auto Intervals = Analyses.getResult<LiveIntervalsAnalysis>(*Fixture->Function, Target);
+  if (!Intervals)
+    return;
+  LiveRegMatrix Matrix(*Fixture->Function, Target, **Intervals);
+  const auto G0Interferences = Matrix.collectInterferences(*Value, G0);
+  const auto G1Interferences = Matrix.collectInterferences(*Value, G1);
+  const auto HasKind = [](std::span<const RegisterInterference> Values,
+                          RegisterInterferenceKind Kind) {
+    return std::ranges::any_of(
+        Values, [Kind](const RegisterInterference &Value) { return Value.Kind == Kind; });
+  };
+  Context.expect(HasKind(G0Interferences, RegisterInterferenceKind::FixedRegister) &&
+                     HasKind(G0Interferences, RegisterInterferenceKind::RegisterMask) &&
+                     !HasKind(G1Interferences, RegisterInterferenceKind::FixedRegister) &&
+                     Matrix.assign(*Value, G1).has_value(),
+                 "LiveRegMatrix must distinguish fixed-register and RegMask interference");
+}
+
+} // namespace
+
+int main() {
+  TestContext Context;
+  auto Target = createTarget();
+  Context.expect(Target.has_value(), "LiveRegMatrix test target must be constructible");
+  if (!Target) {
+    std::cerr << Target.error().message() << '\n';
+    return Context.result();
+  }
+  testLaneAndAssignment(Context, *Target);
+  testFixedAndMaskInterference(Context, *Target);
+  return Context.result();
+}