[CodeGen] Enhance `MachineInstrSpan` to allow the end of MBB to be used.

Summary:
- Explicitly specify the parent MBB to allow the end iterator to be
  used.

Reviewers: aprantl, MatzeB, craig.topper, qcolombet

Subscribers: arsenm, jvesely, nhaehnle, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D64261

llvm-svn: 365240

1 files changed, 33 insertions, 0 deletions

diff --git a/llvm/unittests/CodeGen/MachineInstrTest.cpp b/llvm/unittests/CodeGen/MachineInstrTest.cpp
index 21b5eb6..0f86968 100644
--- a/llvm/unittests/CodeGen/MachineInstrTest.cpp
+++ b/llvm/unittests/CodeGen/MachineInstrTest.cpp
@@ -6,6 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "llvm/CodeGen/MachineBasicBlock.h"
 #include "llvm/CodeGen/MachineInstr.h"
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineModuleInfo.h"
@@ -273,6 +274,38 @@ TEST(MachineInstrPrintingTest, DebugLocPrinting) {
       StringRef(OS.str()).endswith("filename:1:5"));
 }
 
+TEST(MachineInstrSpan, DistanceBegin) {
+  auto MF = createMachineFunction();
+  auto MBB = MF->CreateMachineBasicBlock();
+
+  MCInstrDesc MCID = {0, 0,       0,       0,       0, 0,
+                      0, nullptr, nullptr, nullptr, 0, nullptr};
+
+  auto MII = MBB->begin();
+  MachineInstrSpan MIS(MII, MBB);
+  ASSERT_TRUE(MIS.empty());
+
+  auto MI = MF->CreateMachineInstr(MCID, DebugLoc());
+  MBB->insert(MII, MI);
+  ASSERT_TRUE(std::distance(MIS.begin(), MII) == 1);
+}
+
+TEST(MachineInstrSpan, DistanceEnd) {
+  auto MF = createMachineFunction();
+  auto MBB = MF->CreateMachineBasicBlock();
+
+  MCInstrDesc MCID = {0, 0,       0,       0,       0, 0,
+                      0, nullptr, nullptr, nullptr, 0, nullptr};
+
+  auto MII = MBB->end();
+  MachineInstrSpan MIS(MII, MBB);
+  ASSERT_TRUE(MIS.empty());
+
+  auto MI = MF->CreateMachineInstr(MCID, DebugLoc());
+  MBB->insert(MII, MI);
+  ASSERT_TRUE(std::distance(MIS.begin(), MII) == 1);
+}
+
 static_assert(is_trivially_copyable<MCOperand>::value, "trivially copyable");
 
 } // end namespace