Revert "[DebugInfo] Remove some users of DBG_VALUEs IsIndirect field"

This reverts commit ed29dbaafa49bb8c9039a35f768244c394411fea.

I'm backing out D68945, which as the discussion for D73526 shows, doesn't
seem to handle the -O0 path through the codegen backend correctly. I'll
reland the patch when a fix is worked out, apologies for all the churn.
The two parent commits are part of this revert too.

Conflicts:
	llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
	llvm/test/DebugInfo/X86/dbg-addr-dse.ll

SelectionDAGBuilder conflict is due to a nearby change in e39e2b4a79c6
that's technically unrelated. dbg-addr-dse.ll conflicted because
41206b61e30c (legitimately) changes the order of two lines.

There are further modifications to dbg-value-func-arg.ll: it landed after
the patch being reverted, and I've converted indirection to be represented
by the isIndirect field rather than DW_OP_deref.

(cherry picked from commit 6531a78ac4b5b229bce272706593a0bc873877d7)

2 files changed, 5 insertions, 13 deletions

diff --git a/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp b/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
index 17eca2b0301..96e794b15a4 100644
--- a/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
@@ -1385,7 +1385,7 @@ bool IRTranslator::translateKnownIntrinsic(const CallInst &CI, Intrinsic::ID ID,
     if (!V) {
       // Currently the optimizer can produce this; insert an undef to
       // help debugging.  Probably the optimizer should not do this.
-      MIRBuilder.buildDirectDbgValue(0, DI.getVariable(), DI.getExpression());
+      MIRBuilder.buildIndirectDbgValue(0, DI.getVariable(), DI.getExpression());
     } else if (const auto *CI = dyn_cast<Constant>(V)) {
       MIRBuilder.buildConstDbgValue(*CI, DI.getVariable(), DI.getExpression());
     } else {
diff --git a/llvm/lib/CodeGen/GlobalISel/MachineIRBuilder.cpp b/llvm/lib/CodeGen/GlobalISel/MachineIRBuilder.cpp
index 67d9dacda61..3f6622723bd 100644
--- a/llvm/lib/CodeGen/GlobalISel/MachineIRBuilder.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/MachineIRBuilder.cpp
@@ -107,13 +107,9 @@ MachineIRBuilder::buildIndirectDbgValue(Register Reg, const MDNode *Variable,
   assert(
       cast<DILocalVariable>(Variable)->isValidLocationForIntrinsic(getDL()) &&
       "Expected inlined-at fields to agree");
-  // DBG_VALUE insts now carry IR-level indirection in their DIExpression
-  // rather than encoding it in the instruction itself.
-  const DIExpression *DIExpr = cast<DIExpression>(Expr);
-  DIExpr = DIExpression::append(DIExpr, {dwarf::DW_OP_deref});
   return insertInstr(BuildMI(getMF(), getDL(),
                              getTII().get(TargetOpcode::DBG_VALUE),
-                             /*IsIndirect*/ false, Reg, Variable, DIExpr));
+                             /*IsIndirect*/ true, Reg, Variable, Expr));
 }
 
 MachineInstrBuilder MachineIRBuilder::buildFIDbgValue(int FI,
@@ -124,15 +120,11 @@ MachineInstrBuilder MachineIRBuilder::buildFIDbgValue(int FI,
   assert(
       cast<DILocalVariable>(Variable)->isValidLocationForIntrinsic(getDL()) &&
       "Expected inlined-at fields to agree");
-  // DBG_VALUE insts now carry IR-level indirection in their DIExpression
-  // rather than encoding it in the instruction itself.
-  const DIExpression *DIExpr = cast<DIExpression>(Expr);
-  DIExpr = DIExpression::append(DIExpr, {dwarf::DW_OP_deref});
   return buildInstr(TargetOpcode::DBG_VALUE)
       .addFrameIndex(FI)
-      .addReg(0)
+      .addImm(0)
       .addMetadata(Variable)
-      .addMetadata(DIExpr);
+      .addMetadata(Expr);
 }
 
 MachineInstrBuilder MachineIRBuilder::buildConstDbgValue(const Constant &C,
@@ -156,7 +148,7 @@ MachineInstrBuilder MachineIRBuilder::buildConstDbgValue(const Constant &C,
     MIB.addReg(0U);
   }
 
-  return MIB.addReg(0).addMetadata(Variable).addMetadata(Expr);
+  return MIB.addImm(0).addMetadata(Variable).addMetadata(Expr);
 }
 
 MachineInstrBuilder MachineIRBuilder::buildDbgLabel(const MDNode *Label) {