GlobalISel: implement legalization pass, with just one transformation.

This adds the actual MachineLegalizeHelper to do the work and a trivial pass
wrapper that legalizes all instructions in a MachineFunction. Currently the
only transformation supported is splitting up a vector G_ADD into one acting on
smaller vectors.

llvm-svn: 276461

1 files changed, 32 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/GlobalISel/MachineIRBuilder.cpp b/llvm/lib/CodeGen/GlobalISel/MachineIRBuilder.cpp
index 220965ce660..2b91584c75d 100644
--- a/llvm/lib/CodeGen/GlobalISel/MachineIRBuilder.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/MachineIRBuilder.cpp
@@ -110,3 +110,35 @@ MachineInstr *MachineIRBuilder::buildFrameIndex(LLT Ty, unsigned Res, int Idx) {
   MIB.addImm(Idx);
   return NewMI;
 }
+
+MachineInstr *MachineIRBuilder::buildAdd(LLT Ty, unsigned Res, unsigned Op0,
+                                         unsigned Op1) {
+  return buildInstr(TargetOpcode::G_ADD, Ty, Res, Op0, Op1);
+}
+
+MachineInstr *MachineIRBuilder::buildExtract(LLT Ty, ArrayRef<unsigned> Results,
+                                             unsigned Src,
+                                             ArrayRef<unsigned> Indexes) {
+  assert(Results.size() == Indexes.size() && "inconsistent number of regs");
+
+  MachineInstr *NewMI = buildInstr(TargetOpcode::G_EXTRACT, Ty);
+  auto MIB = MachineInstrBuilder(getMF(), NewMI);
+  for (auto Res : Results)
+    MIB.addReg(Res, RegState::Define);
+
+  MIB.addReg(Src);
+
+  for (auto Idx : Indexes)
+    MIB.addImm(Idx);
+  return NewMI;
+}
+
+MachineInstr *MachineIRBuilder::buildSequence(LLT Ty, unsigned Res,
+                                              ArrayRef<unsigned> Ops) {
+  MachineInstr *NewMI = buildInstr(TargetOpcode::G_SEQUENCE, Ty);
+  auto MIB = MachineInstrBuilder(getMF(), NewMI);
+  MIB.addReg(Res, RegState::Define);
+  for (auto Op : Ops)
+    MIB.addReg(Op);
+  return NewMI;
+}