From 0aa201eaf97681f59b72baee6552aa1b9b5c9129 Mon Sep 17 00:00:00 2001
From: Vedant Kumar <vsk@apple.com>
Date: Wed, 27 May 2020 13:13:13 -0700
Subject: [PATCH] [MachineLICM] Assert that locations from debug insts are not
 lost

Summary:
Assert that MachineLICM does not move a debug instruction and then drop
its debug location. Later passes require each debug instruction to have
a location.

Testing: check-llvm, clang stage2 RelWithDebInfo build (x86_64)

Reviewers: aprantl, davide, chrisjackson, jmorse

Subscribers: hiraditya, asbirlea, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D80665
---
 llvm/lib/CodeGen/MachineLICM.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/llvm/lib/CodeGen/MachineLICM.cpp b/llvm/lib/CodeGen/MachineLICM.cpp
index 2a60858b6de2..98638b9fa737 100644
--- a/llvm/lib/CodeGen/MachineLICM.cpp
+++ b/llvm/lib/CodeGen/MachineLICM.cpp
@@ -638,6 +638,7 @@ void MachineLICMBase::HoistPostRA(MachineInstr *MI, unsigned Def) {
   // Since we are moving the instruction out of its basic block, we do not
   // retain its debug location. Doing so would degrade the debugging
   // experience and adversely affect the accuracy of profiling information.
+  assert(!MI->isDebugInstr() && "Should not hoist debug inst");
   MI->setDebugLoc(DebugLoc());
 
   // Add register to livein list to all the BBs in the current loop since a
@@ -841,6 +842,7 @@ void MachineLICMBase::SinkIntoLoop() {
 
     // The instruction is is moved from its basic block, so do not retain the
     // debug information.
+    assert(!I->isDebugInstr() && "Should not sink debug inst");
     I->setDebugLoc(DebugLoc());
   }
 }
@@ -1536,6 +1538,7 @@ bool MachineLICMBase::Hoist(MachineInstr *MI, MachineBasicBlock *Preheader) {
     // Since we are moving the instruction out of its basic block, we do not
     // retain its debug location. Doing so would degrade the debugging
     // experience and adversely affect the accuracy of profiling information.
+    assert(!MI->isDebugInstr() && "Should not hoist debug inst");
     MI->setDebugLoc(DebugLoc());
 
     // Update register pressure for BBs from header to this block.