1 files changed, 42 insertions, 25 deletions

diff --git a/llvm/lib/CodeGen/MachineOutliner.cpp b/llvm/lib/CodeGen/MachineOutliner.cpp
index 7ce655d..e742642 100644
--- a/llvm/lib/CodeGen/MachineOutliner.cpp
+++ b/llvm/lib/CodeGen/MachineOutliner.cpp
@@ -258,6 +258,10 @@ struct InstructionMapper {
     if (!TII.isMBBSafeToOutlineFrom(MBB, Flags))
       return;
 
+    auto Ranges = TII.getOutlinableRanges(MBB, Flags);
+    if (Ranges.empty())
+      return;
+
     // Store info for the MBB for later outlining.
     MBBFlagsMap[&MBB] = Flags;
 
@@ -280,34 +284,47 @@ struct InstructionMapper {
     std::vector<unsigned> UnsignedVecForMBB;
     std::vector<MachineBasicBlock::iterator> InstrListForMBB;
 
-    for (MachineBasicBlock::iterator Et = MBB.end(); It != Et; ++It) {
-      // Keep track of where this instruction is in the module.
-      switch (TII.getOutliningType(It, Flags)) {
-      case InstrType::Illegal:
+    for (auto &Range : Ranges) {
+      auto RangeStart = Range.first;
+      auto RangeEnd = Range.second;
+      // Everything outside of an outlinable range is illegal.
+      for (; It != RangeStart; ++It)
         mapToIllegalUnsigned(It, CanOutlineWithPrevInstr, UnsignedVecForMBB,
                              InstrListForMBB);
-        break;
-
-      case InstrType::Legal:
-        mapToLegalUnsigned(It, CanOutlineWithPrevInstr, HaveLegalRange,
-                           NumLegalInBlock, UnsignedVecForMBB, InstrListForMBB);
-        break;
-
-      case InstrType::LegalTerminator:
-        mapToLegalUnsigned(It, CanOutlineWithPrevInstr, HaveLegalRange,
-                           NumLegalInBlock, UnsignedVecForMBB, InstrListForMBB);
-        // The instruction also acts as a terminator, so we have to record that
-        // in the string.
-        mapToIllegalUnsigned(It, CanOutlineWithPrevInstr, UnsignedVecForMBB,
+      assert(It != MBB.end() && "Should still have instructions?");
+      // `It` is now positioned at the beginning of a range of instructions
+      // which may be outlinable. Check if each instruction is known to be safe.
+      for (; It != RangeEnd; ++It) {
+        // Keep track of where this instruction is in the module.
+        switch (TII.getOutliningType(It, Flags)) {
+        case InstrType::Illegal:
+          mapToIllegalUnsigned(It, CanOutlineWithPrevInstr, UnsignedVecForMBB,
+                               InstrListForMBB);
+          break;
+
+        case InstrType::Legal:
+          mapToLegalUnsigned(It, CanOutlineWithPrevInstr, HaveLegalRange,
+                             NumLegalInBlock, UnsignedVecForMBB,
                              InstrListForMBB);
-        break;
-
-      case InstrType::Invisible:
-        // Normally this is set by mapTo(Blah)Unsigned, but we just want to
-        // skip this instruction. So, unset the flag here.
-        ++NumInvisible;
-        AddedIllegalLastTime = false;
-        break;
+          break;
+
+        case InstrType::LegalTerminator:
+          mapToLegalUnsigned(It, CanOutlineWithPrevInstr, HaveLegalRange,
+                             NumLegalInBlock, UnsignedVecForMBB,
+                             InstrListForMBB);
+          // The instruction also acts as a terminator, so we have to record
+          // that in the string.
+          mapToIllegalUnsigned(It, CanOutlineWithPrevInstr, UnsignedVecForMBB,
+                               InstrListForMBB);
+          break;
+
+        case InstrType::Invisible:
+          // Normally this is set by mapTo(Blah)Unsigned, but we just want to
+          // skip this instruction. So, unset the flag here.
+          ++NumInvisible;
+          AddedIllegalLastTime = false;
+          break;
+        }
       }
     }