[globalisel][tablegen] Factor out implicit def/use renderers from createAndImportInst...

Multi-instruction emission will require that we have separate handling for
the defs between the implicitly created temporaries and the rule outputs.
The former require new temporary vregs while the latter should copy existing
operands. Factor out the implicit def/use renderers to minimize the code
duplication when we implement that.

llvm-svn: 317025

diff --git a/llvm/utils/TableGen/GlobalISelEmitter.cpp b/llvm/utils/TableGen/GlobalISelEmitter.cpp
index daa958e..9a38d92 100644 (file)
--- a/llvm/utils/TableGen/GlobalISelEmitter.cpp
+++ b/llvm/utils/TableGen/GlobalISelEmitter.cpp
@@ -1798,6 +1798,8 @@ public:
   BuildMIAction(unsigned InsnID, const CodeGenInstruction *I)
       : InsnID(InsnID), I(I), Matched(nullptr) {}
 
+  const CodeGenInstruction *getCGI() const { return I; }
+
   void chooseInsnToMutate(RuleMatcher &Rule) {
     for (const auto *MutateCandidate : Rule.mutatable_insns()) {
       if (canMutate(Rule, MutateCandidate)) {
@@ -2219,9 +2221,16 @@ private:
                            const TreePatternNode *SrcChild,
                            bool OperandIsAPointer, unsigned OpIdx,
                            unsigned &TempOpIdx) const;
+
   Expected<BuildMIAction &>
   createAndImportInstructionRenderer(RuleMatcher &M,
                                      const TreePatternNode *Dst);
+  Expected<BuildMIAction &>
+  createInstructionRenderer(RuleMatcher &M, const TreePatternNode *Dst);
+  void importExplicitDefRenderers(BuildMIAction &DstMIBuilder);
+  Expected<BuildMIAction &>
+  importExplicitUseRenderers(RuleMatcher &M, BuildMIAction &DstMIBuilder,
+                             const llvm::TreePatternNode *Dst);
   Error importExplicitUseRenderer(RuleMatcher &Rule,
                                   BuildMIAction &DstMIBuilder,
                                   TreePatternNode *DstChild) const;
@@ -2657,6 +2666,22 @@ Error GlobalISelEmitter::importExplicitUseRenderer(
 
 Expected<BuildMIAction &> GlobalISelEmitter::createAndImportInstructionRenderer(
     RuleMatcher &M, const TreePatternNode *Dst) {
+  auto DstMIBuilderOrError = createInstructionRenderer(M, Dst);
+  if (auto Error = DstMIBuilderOrError.takeError())
+    return std::move(Error);
+
+  BuildMIAction &DstMIBuilder = DstMIBuilderOrError.get();
+
+  importExplicitDefRenderers(DstMIBuilder);
+
+  if (auto Error = importExplicitUseRenderers(M, DstMIBuilder, Dst).takeError())
+    return std::move(Error);
+
+  return DstMIBuilder;
+}
+
+Expected<BuildMIAction &> GlobalISelEmitter::createInstructionRenderer(
+    RuleMatcher &M, const TreePatternNode *Dst) {
   Record *DstOp = Dst->getOperator();
   if (!DstOp->isSubClassOf("Instruction")) {
     if (DstOp->isSubClassOf("ValueType"))
@@ -2666,31 +2691,35 @@ Expected<BuildMIAction &> GlobalISelEmitter::createAndImportInstructionRenderer(
   }
   CodeGenInstruction *DstI = &Target.getInstruction(DstOp);
 
-  unsigned DstINumUses = DstI->Operands.size() - DstI->Operands.NumDefs;
-  unsigned ExpectedDstINumUses = Dst->getNumChildren();
-  bool IsExtractSubReg = false;
-
   // COPY_TO_REGCLASS is just a copy with a ConstrainOperandToRegClassAction
   // attached. Similarly for EXTRACT_SUBREG except that's a subregister copy.
-  if (DstI->TheDef->getName() == "COPY_TO_REGCLASS") {
+  if (DstI->TheDef->getName() == "COPY_TO_REGCLASS")
     DstI = &Target.getInstruction(RK.getDef("COPY"));
-    DstINumUses--; // Ignore the class constraint.
-    ExpectedDstINumUses--;
-  } else if (DstI->TheDef->getName() == "EXTRACT_SUBREG") {
+  else if (DstI->TheDef->getName() == "EXTRACT_SUBREG")
     DstI = &Target.getInstruction(RK.getDef("COPY"));
-    IsExtractSubReg = true;
-  }
 
   auto &DstMIBuilder = M.addAction<BuildMIAction>(0, DstI);
 
-  // Render the explicit defs.
+  return DstMIBuilder;
+}
+
+void GlobalISelEmitter::importExplicitDefRenderers(
+    BuildMIAction &DstMIBuilder) {
+  const CodeGenInstruction *DstI = DstMIBuilder.getCGI();
   for (unsigned I = 0; I < DstI->Operands.NumDefs; ++I) {
     const CGIOperandList::OperandInfo &DstIOperand = DstI->Operands[I];
     DstMIBuilder.addRenderer<CopyRenderer>(0, DstIOperand.Name);
   }
+}
+
+Expected<BuildMIAction &> GlobalISelEmitter::importExplicitUseRenderers(
+    RuleMatcher &M, BuildMIAction &DstMIBuilder,
+    const llvm::TreePatternNode *Dst) {
+  const CodeGenInstruction *DstI = DstMIBuilder.getCGI();
+  CodeGenInstruction *OrigDstI = &Target.getInstruction(Dst->getOperator());
 
   // EXTRACT_SUBREG needs to use a subregister COPY.
-  if (IsExtractSubReg) {
+  if (OrigDstI->TheDef->getName() == "EXTRACT_SUBREG") {
     if (!Dst->getChild(0)->isLeaf())
       return failedImport("EXTRACT_SUBREG child #1 is not a leaf");
 
@@ -2717,6 +2746,13 @@ Expected<BuildMIAction &> GlobalISelEmitter::createAndImportInstructionRenderer(
   }
 
   // Render the explicit uses.
+  unsigned DstINumUses = OrigDstI->Operands.size() - OrigDstI->Operands.NumDefs;
+  unsigned ExpectedDstINumUses = Dst->getNumChildren();
+  if (OrigDstI->TheDef->getName() == "COPY_TO_REGCLASS") {
+    DstINumUses--; // Ignore the class constraint.
+    ExpectedDstINumUses--;
+  }
+
   unsigned Child = 0;
   unsigned NumDefaultOps = 0;
   for (unsigned I = 0; I != DstINumUses; ++I) {