[GlobalISel] Add unit tests for call lowering on byref support

llvm/unittests/CodeGen/GlobalISel/CMakeLists.txt

@@ -1,5 +1,6 @@
 set(LLVM_LINK_COMPONENTS
   ${LLVM_TARGETS_TO_BUILD}
+  AsmParser
   CodeGen
   CodeGenTypes
   Core
@@ -26,4 +27,5 @@ add_llvm_unittest(GlobalISelTests
   KnownBitsVectorTest.cpp
   GISelUtilsTest.cpp
   GISelAliasTest.cpp
+  CallLowering.cpp
   )

llvm/unittests/CodeGen/GlobalISel/CallLowering.cpp

@@ -0,0 +1,57 @@
+//===- CallLowering.cpp - CallLowering unit tests -------------------------===//
+//
+// 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/CodeGen/GlobalISel/CallLowering.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/AsmParser/Parser.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Support/SourceMgr.h"
+#include "gtest/gtest.h"
+
+using namespace llvm;
+
+namespace {
+struct TargetCallLoweringTest : public CallLowering, testing::Test {
+  LLVMContext C;
+
+public:
+  TargetCallLoweringTest() : CallLowering(nullptr) {}
+
+  std::unique_ptr<Module> parseIR(const char *IR) {
+    SMDiagnostic Err;
+    std::unique_ptr<Module> Mod = parseAssemblyString(IR, Err, C);
+    if (!Mod)
+      Err.print("TestTargetCallLoweringTest", errs());
+    return Mod;
+  }
+};
+} // namespace
+
+TEST_F(TargetCallLoweringTest, ArgByRef) {
+  std::unique_ptr<Module> M = parseIR(R"(
+define void @foo(ptr %p0, ptr byref(i32) align(4) %p1) {
+  ret void
+}
+)");
+  const DataLayout &DL = M->getDataLayout();
+  Function *F = M->getFunction("foo");
+  // Dummy vregs.
+  SmallVector<Register, 4> VRegs(1, 1);
+
+  CallLowering::ArgInfo Arg0(VRegs, F->getArg(0)->getType(), 0);
+  setArgFlags(Arg0, AttributeList::FirstArgIndex + 0, DL, *F);
+  EXPECT_TRUE(Arg0.Flags[0].isPointer());
+  EXPECT_FALSE(Arg0.Flags[0].isByRef());
+
+  CallLowering::ArgInfo Arg1(VRegs, F->getArg(1)->getType(), 1);
+  setArgFlags(Arg1, AttributeList::FirstArgIndex + 1, DL, *F);
+  EXPECT_TRUE(Arg1.Flags[0].isPointer());
+  EXPECT_TRUE(Arg1.Flags[0].isByRef());
+  EXPECT_EQ(Arg1.Flags[0].getByRefSize(), 4U);
+}