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)

1 files changed, 5 insertions, 7 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/FastISel.cpp b/llvm/lib/CodeGen/SelectionDAG/FastISel.cpp
index 2bec8613e79..8294591b732 100644
--- a/llvm/lib/CodeGen/SelectionDAG/FastISel.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/FastISel.cpp
@@ -1393,11 +1393,9 @@ bool FastISel::selectIntrinsicCall(const IntrinsicInst *II) {
              "Expected inlined-at fields to agree");
       // A dbg.declare describes the address of a source variable, so lower it
       // into an indirect DBG_VALUE.
-      auto *Expr = DI->getExpression();
-      Expr = DIExpression::append(Expr, {dwarf::DW_OP_deref});
       BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
-              TII.get(TargetOpcode::DBG_VALUE), /*IsIndirect*/ false,
-              *Op, DI->getVariable(), Expr);
+              TII.get(TargetOpcode::DBG_VALUE), /*IsIndirect*/ true,
+              *Op, DI->getVariable(), DI->getExpression());
     } else {
       // We can't yet handle anything else here because it would require
       // generating code, thus altering codegen because of debug info.
@@ -1421,19 +1419,19 @@ bool FastISel::selectIntrinsicCall(const IntrinsicInst *II) {
       if (CI->getBitWidth() > 64)
         BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, II)
             .addCImm(CI)
-            .addReg(0U)
+            .addImm(0U)
             .addMetadata(DI->getVariable())
             .addMetadata(DI->getExpression());
       else
         BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, II)
             .addImm(CI->getZExtValue())
-            .addReg(0U)
+            .addImm(0U)
             .addMetadata(DI->getVariable())
             .addMetadata(DI->getExpression());
     } else if (const auto *CF = dyn_cast<ConstantFP>(V)) {
       BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, II)
           .addFPImm(CF)
-          .addReg(0U)
+          .addImm(0U)
           .addMetadata(DI->getVariable())
           .addMetadata(DI->getExpression());
     } else if (unsigned Reg = lookUpRegForValue(V)) {