From 1023a2eca3f003c19532d5659f44bef169ab4519 Mon Sep 17 00:00:00 2001
From: Aditya Nandakumar <aditya_nandakumar@apple.com>
Date: Mon, 1 Jul 2019 17:53:50 +0000
Subject: [PATCH] [GlobalISel]: Allow backends to custom legalize Intrinsics

https://reviews.llvm.org/D31359

Add a hook "legalizeInstrinsic" to allow backends to override this
and custom lower/legalize intrinsics.

llvm-svn: 364821
---
 llvm/include/llvm/CodeGen/GlobalISel/LegalizerInfo.h | 5 +++++
 llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp      | 4 ++++
 llvm/lib/CodeGen/GlobalISel/LegalizerInfo.cpp        | 6 ++++++
 3 files changed, 15 insertions(+)

diff --git a/llvm/include/llvm/CodeGen/GlobalISel/LegalizerInfo.h b/llvm/include/llvm/CodeGen/GlobalISel/LegalizerInfo.h
index 7b7c899..513c98f 100644
--- a/llvm/include/llvm/CodeGen/GlobalISel/LegalizerInfo.h
+++ b/llvm/include/llvm/CodeGen/GlobalISel/LegalizerInfo.h
@@ -1114,6 +1114,11 @@ public:
                               MachineIRBuilder &MIRBuilder,
                               GISelChangeObserver &Observer) const;
 
+  /// Return true if MI is either legal or has been legalized and false
+  /// if not legal.
+  virtual bool legalizeIntrinsic(MachineInstr &MI, MachineRegisterInfo &MRI,
+                                 MachineIRBuilder &MIRBuilder) const;
+
 private:
   /// Determine what action should be taken to legalize the given generic
   /// instruction opcode, type-index and type. Requires computeTables to have
diff --git a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
index 88c9715..d62e786 100644
--- a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
@@ -82,6 +82,10 @@ LegalizerHelper::LegalizeResult
 LegalizerHelper::legalizeInstrStep(MachineInstr &MI) {
   LLVM_DEBUG(dbgs() << "Legalizing: "; MI.print(dbgs()));
 
+  if (MI.getOpcode() == TargetOpcode::G_INTRINSIC ||
+      MI.getOpcode() == TargetOpcode::G_INTRINSIC_W_SIDE_EFFECTS)
+    return LI.legalizeIntrinsic(MI, MRI, MIRBuilder) ? Legalized
+                                                     : UnableToLegalize;
   auto Step = LI.getAction(MI, MRI);
   switch (Step.Action) {
   case Legal:
diff --git a/llvm/lib/CodeGen/GlobalISel/LegalizerInfo.cpp b/llvm/lib/CodeGen/GlobalISel/LegalizerInfo.cpp
index 14df53b..6e1de95 100644
--- a/llvm/lib/CodeGen/GlobalISel/LegalizerInfo.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/LegalizerInfo.cpp
@@ -658,6 +658,12 @@ LegalizerInfo::findVectorLegalAction(const InstrAspect &Aspect) const {
                       IntermediateType.getScalarSizeInBits())};
 }
 
+bool LegalizerInfo::legalizeIntrinsic(MachineInstr &MI,
+                                      MachineRegisterInfo &MRI,
+                                      MachineIRBuilder &MIRBuilder) const {
+  return true;
+}
+
 /// \pre Type indices of every opcode form a dense set starting from 0.
 void LegalizerInfo::verify(const MCInstrInfo &MII) const {
 #ifndef NDEBUG
-- 
2.7.4