[WebAssembly] Convert a regular for loop to a range-based for loop.

[oota-llvm.git] / lib / Target / WebAssembly / WebAssemblyInstrInfo.cpp

diff --git a/lib/Target/WebAssembly/WebAssemblyInstrInfo.cpp b/lib/Target/WebAssembly/WebAssemblyInstrInfo.cpp
index 1898ad8f8eb956eff1511b35176113541f223b68..5e7663cdb5063f7190a4e966e71bfce47b04da38 100644 (file)
--- a/lib/Target/WebAssembly/WebAssemblyInstrInfo.cpp
+++ b/lib/Target/WebAssembly/WebAssemblyInstrInfo.cpp
@@ -28,12 +28,132 @@ using namespace llvm;
 #include "WebAssemblyGenInstrInfo.inc"
 
 WebAssemblyInstrInfo::WebAssemblyInstrInfo(const WebAssemblySubtarget &STI)
-    : RI(STI.getTargetTriple()) {}
+    : WebAssemblyGenInstrInfo(WebAssembly::ADJCALLSTACKDOWN,
+                              WebAssembly::ADJCALLSTACKUP),
+      RI(STI.getTargetTriple()) {}
 
 void WebAssemblyInstrInfo::copyPhysReg(MachineBasicBlock &MBB,
                                        MachineBasicBlock::iterator I,
                                        DebugLoc DL, unsigned DestReg,
                                        unsigned SrcReg, bool KillSrc) const {
-  BuildMI(MBB, I, DL, get(WebAssembly::COPY), DestReg)
+  // This method is called by post-RA expansion, which expects only pregs to
+  // exist. However we need to handle both here.
+  auto &MRI = MBB.getParent()->getRegInfo();
+  const TargetRegisterClass *RC = TargetRegisterInfo::isVirtualRegister(DestReg) ?
+      MRI.getRegClass(DestReg) :
+      MRI.getTargetRegisterInfo()->getMinimalPhysRegClass(SrcReg);
+
+  unsigned CopyLocalOpcode;
+  if (RC == &WebAssembly::I32RegClass)
+    CopyLocalOpcode = WebAssembly::COPY_LOCAL_I32;
+  else if (RC == &WebAssembly::I64RegClass)
+    CopyLocalOpcode = WebAssembly::COPY_LOCAL_I64;
+  else if (RC == &WebAssembly::F32RegClass)
+    CopyLocalOpcode = WebAssembly::COPY_LOCAL_F32;
+  else if (RC == &WebAssembly::F64RegClass)
+    CopyLocalOpcode = WebAssembly::COPY_LOCAL_F64;
+  else
+    llvm_unreachable("Unexpected register class");
+
+  BuildMI(MBB, I, DL, get(CopyLocalOpcode), DestReg)
       .addReg(SrcReg, KillSrc ? RegState::Kill : 0);
 }
+
+// Branch analysis.
+bool WebAssemblyInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,
+                                         MachineBasicBlock *&TBB,
+                                         MachineBasicBlock *&FBB,
+                                         SmallVectorImpl<MachineOperand> &Cond,
+                                         bool /*AllowModify*/) const {
+  bool HaveCond = false;
+  for (MachineInstr &MI : MBB.terminators()) {
+    switch (MI.getOpcode()) {
+    default:
+      // Unhandled instruction; bail out.
+      return true;
+    case WebAssembly::BR_IF:
+      if (HaveCond)
+        return true;
+      Cond.push_back(MachineOperand::CreateImm(true));
+      Cond.push_back(MI.getOperand(0));
+      TBB = MI.getOperand(1).getMBB();
+      HaveCond = true;
+      break;
+    case WebAssembly::BR_UNLESS:
+      if (HaveCond)
+        return true;
+      Cond.push_back(MachineOperand::CreateImm(false));
+      Cond.push_back(MI.getOperand(0));
+      TBB = MI.getOperand(1).getMBB();
+      HaveCond = true;
+      break;
+    case WebAssembly::BR:
+      if (!HaveCond)
+        TBB = MI.getOperand(0).getMBB();
+      else
+        FBB = MI.getOperand(0).getMBB();
+      break;
+    }
+    if (MI.isBarrier())
+      break;
+  }
+
+  return false;
+}
+
+unsigned WebAssemblyInstrInfo::RemoveBranch(MachineBasicBlock &MBB) const {
+  MachineBasicBlock::instr_iterator I = MBB.instr_end();
+  unsigned Count = 0;
+
+  while (I != MBB.instr_begin()) {
+    --I;
+    if (I->isDebugValue())
+      continue;
+    if (!I->isTerminator())
+      break;
+    // Remove the branch.
+    I->eraseFromParent();
+    I = MBB.instr_end();
+    ++Count;
+  }
+
+  return Count;
+}
+
+unsigned WebAssemblyInstrInfo::InsertBranch(MachineBasicBlock &MBB,
+                                            MachineBasicBlock *TBB,
+                                            MachineBasicBlock *FBB,
+                                            ArrayRef<MachineOperand> Cond,
+                                            DebugLoc DL) const {
+  if (Cond.empty()) {
+    if (!TBB)
+      return 0;
+
+    BuildMI(&MBB, DL, get(WebAssembly::BR)).addMBB(TBB);
+    return 1;
+  }
+
+  assert(Cond.size() == 2 && "Expected a flag and a successor block");
+
+  if (Cond[0].getImm()) {
+    BuildMI(&MBB, DL, get(WebAssembly::BR_IF))
+        .addOperand(Cond[1])
+        .addMBB(TBB);
+  } else {
+    BuildMI(&MBB, DL, get(WebAssembly::BR_UNLESS))
+        .addOperand(Cond[1])
+        .addMBB(TBB);
+  }
+  if (!FBB)
+    return 1;
+
+  BuildMI(&MBB, DL, get(WebAssembly::BR)).addMBB(FBB);
+  return 2;
+}
+
+bool WebAssemblyInstrInfo::ReverseBranchCondition(
+    SmallVectorImpl<MachineOperand> &Cond) const {
+  assert(Cond.size() == 2 && "Expected a flag and a successor block");
+  Cond.front() = MachineOperand::CreateImm(!Cond.front().getImm());
+  return false;
+}