MachineFunction: Copy call site info when duplicating insts

Summary:
Preserve call site info for duplicated instructions. We copy over the
call site info in CloneMachineInstrBundle to avoid repeated calls to
copyCallSiteInfo in CloneMachineInstr.

(Alternatively, we could copy call site info higher up the stack, e.g.
into TargetInstrInfo::duplicate, or even into individual backend passes.
However, I don't see how that would be safer or more general than the
current approach.)

Reviewers: aprantl, djtodoro, dstenb

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D77685

1 files changed, 20 insertions, 0 deletions

diff --git a/llvm/unittests/CodeGen/MachineInstrTest.cpp b/llvm/unittests/CodeGen/MachineInstrTest.cpp
index 33baaf62..71c4b8e 100644
--- a/llvm/unittests/CodeGen/MachineInstrTest.cpp
+++ b/llvm/unittests/CodeGen/MachineInstrTest.cpp
@@ -383,6 +383,26 @@ TEST(MachineInstrExtraInfo, RemoveExtraInfo) {
   ASSERT_FALSE(MI->getHeapAllocMarker());
 }
 
+TEST(MachineInstrClone, CopyCallSiteInfo) {
+  LLVMContext Ctx;
+  Module Mod("Module", Ctx);
+  auto MF = createMachineFunction(Ctx, Mod);
+  auto MBB = MF->CreateMachineBasicBlock();
+  auto MII = MBB->begin();
+
+  MCInstrDesc MCID = {0, 0,       0,       0,      0, (1ULL << MCID::Call),
+                      0, nullptr, nullptr, nullptr};
+
+  MachineFunction::CallSiteInfo CSInfo;
+  auto MI = MF->CreateMachineInstr(MCID, DebugLoc());
+  ASSERT_TRUE(MI->isCandidateForCallSiteEntry());
+  MBB->insert(MII, MI);
+  MF->addCallArgsForwardingRegs(MI, std::move(CSInfo));
+  EXPECT_EQ(MF->getCallSitesInfo().size(), 1u);
+  MF->CloneMachineInstrBundle(*MBB, MBB->end(), *MI);
+  EXPECT_EQ(MF->getCallSitesInfo().size(), 2u);
+}
+
 static_assert(is_trivially_copyable<MCOperand>::value, "trivially copyable");
 
 } // end namespace