GlobalISel: translate insertvalue instructions.

This adds a G_INSERT instruction, which technically makes G_SEQUENCE redundant
(it's equivalent to a G_INSERT into an IMPLICIT_DEF). We'll leave G_SEQUENCE
for now though: it's likely to be far more common as it's a fundamental part of
legalization, so avoiding the mess and bloat of the extra IMPLICIT_DEFs is
probably worthwhile.

llvm-svn: 279306

1 files changed, 24 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp b/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
index 545b85f1c21..fb348e9a6c7 100644
--- a/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
@@ -203,6 +203,30 @@ bool IRTranslator::translateExtractValue(const User &U) {
   return true;
 }
 
+bool IRTranslator::translateInsertValue(const User &U) {
+  const InsertValueInst &IVI = cast<InsertValueInst>(U);
+  const Value *Src = IVI.getAggregateOperand();
+  Type *Int32Ty = Type::getInt32Ty(IVI.getContext());
+  SmallVector<Value *, 1> Indices;
+
+  // getIndexedOffsetInType is designed for GEPs, so the first index is the
+  // usual array element rather than looking into the actual aggregate.
+  Indices.push_back(ConstantInt::get(Int32Ty, 0));
+  for (auto Idx : IVI.indices())
+    Indices.push_back(ConstantInt::get(Int32Ty, Idx));
+
+  uint64_t Offset = 8 * DL->getIndexedOffsetInType(Src->getType(), Indices);
+
+  unsigned Res = getOrCreateVReg(IVI);
+  const Value &Inserted = *IVI.getInsertedValueOperand();
+  MIRBuilder.buildInsert(
+      LLT{*IVI.getType(), DL}, Res, getOrCreateVReg(*IVI.getAggregateOperand()),
+      LLT{*Inserted.getType(), DL}, getOrCreateVReg(Inserted), Offset);
+
+  return true;
+}
+
+
 bool IRTranslator::translateBitCast(const User &U) {
   if (LLT{*U.getOperand(0)->getType()} == LLT{*U.getType()}) {
     unsigned &Reg = ValToVReg[&U];