GlobalISel: support translation of intrinsic calls.

These come in two variants for now: G_INTRINSIC and G_INTRINSIC_W_SIDE_EFFECTS.
We may decide to split the latter up with finer-grained restrictions later, if
necessary.

llvm-svn: 277224

2 files changed, 48 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp b/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
index b0751c0bb5e..80ec1b529d3 100644
--- a/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
@@ -19,8 +19,10 @@
 #include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/IR/Constant.h"
 #include "llvm/IR/Function.h"
+#include "llvm/IR/IntrinsicInst.h"
 #include "llvm/IR/Type.h"
 #include "llvm/IR/Value.h"
+#include "llvm/Target/TargetIntrinsicInfo.h"
 #include "llvm/Target/TargetLowering.h"
 
 #define DEBUG_TYPE "irtranslator"
@@ -175,6 +177,34 @@ bool IRTranslator::translateCast(unsigned Opcode, const CastInst &CI) {
   return true;
 }
 
+bool IRTranslator::translateCall(const CallInst &CI) {
+  auto TII = MIRBuilder.getMF().getTarget().getIntrinsicInfo();
+  const Function &F = *CI.getCalledFunction();
+  Intrinsic::ID ID = F.getIntrinsicID();
+  if (TII && ID == Intrinsic::not_intrinsic)
+    ID = static_cast<Intrinsic::ID>(TII->getIntrinsicID(&F));
+
+  assert(ID != Intrinsic::not_intrinsic && "FIXME: support real calls");
+
+  // Need types (starting with return) & args.
+  SmallVector<LLT, 4> Tys;
+  Tys.emplace_back(*CI.getType());
+  for (auto &Arg : CI.arg_operands())
+    Tys.emplace_back(*Arg->getType());
+
+  unsigned Res = CI.getType()->isVoidTy() ? 0 : getOrCreateVReg(CI);
+  MachineInstrBuilder MIB =
+      MIRBuilder.buildIntrinsic(Tys, ID, Res, !CI.doesNotAccessMemory());
+
+  for (auto &Arg : CI.arg_operands()) {
+    if (ConstantInt *CI = dyn_cast<ConstantInt>(Arg))
+      MIB.addImm(CI->getSExtValue());
+    else
+      MIB.addUse(getOrCreateVReg(*Arg));
+  }
+  return true;
+}
+
 bool IRTranslator::translateStaticAlloca(const AllocaInst &AI) {
   assert(AI.isStaticAlloca() && "only handle static allocas now");
   MachineFunction &MF = MIRBuilder.getMF();
@@ -218,6 +248,10 @@ bool IRTranslator::translate(const Instruction &Inst) {
   case Instruction::Ret:
     return translateReturn(cast<ReturnInst>(Inst));
 
+  // Calls
+  case Instruction::Call:
+    return translateCall(cast<CallInst>(Inst));
+
   // Casts
   case Instruction::BitCast:
     return translateBitCast(cast<CastInst>(Inst));
diff --git a/llvm/lib/CodeGen/GlobalISel/MachineIRBuilder.cpp b/llvm/lib/CodeGen/GlobalISel/MachineIRBuilder.cpp
index 426de444d88..5e737d5e2bb 100644
--- a/llvm/lib/CodeGen/GlobalISel/MachineIRBuilder.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/MachineIRBuilder.cpp
@@ -143,3 +143,17 @@ MachineInstrBuilder MachineIRBuilder::buildSequence(LLT Ty, unsigned Res,
     MIB.addUse(Op);
   return MIB;
 }
+
+MachineInstrBuilder MachineIRBuilder::buildIntrinsic(ArrayRef<LLT> Tys,
+                                                     Intrinsic::ID ID,
+                                                     unsigned Res,
+                                                     bool HasSideEffects) {
+  auto MIB =
+      buildInstr(HasSideEffects ? TargetOpcode::G_INTRINSIC_W_SIDE_EFFECTS
+                                : TargetOpcode::G_INTRINSIC,
+                 Tys);
+  if (Res)
+    MIB.addDef(Res);
+  MIB.addIntrinsicID(ID);
+  return MIB;
+}