Vendor import of llvm trunk r256633:

https://llvm.org/svn/llvm-project/llvm/trunk@256633

1 files changed, 60 insertions, 32 deletions

diff --git a/include/llvm/CodeGen/MachineInstr.h b/include/llvm/CodeGen/MachineInstr.h
index de7e0a2..978864e 100644
--- a/include/llvm/CodeGen/MachineInstr.h
+++ b/include/llvm/CodeGen/MachineInstr.h
@@ -23,6 +23,7 @@
 #include "llvm/ADT/ilist.h"
 #include "llvm/ADT/ilist_node.h"
 #include "llvm/ADT/iterator_range.h"
+#include "llvm/Analysis/AliasAnalysis.h"
 #include "llvm/CodeGen/MachineOperand.h"
 #include "llvm/IR/DebugInfo.h"
 #include "llvm/IR/DebugLoc.h"
@@ -34,7 +35,6 @@
 namespace llvm {
 
 template <typename T> class SmallVectorImpl;
-class AliasAnalysis;
 class TargetInstrInfo;
 class TargetRegisterClass;
 class TargetRegisterInfo;
@@ -48,7 +48,8 @@ class MachineMemOperand;
 /// MachineFunction is deleted, all the contained MachineInstrs are deallocated
 /// without having their destructor called.
 ///
-class MachineInstr : public ilist_node<MachineInstr> {
+class MachineInstr
+    : public ilist_node_with_parent<MachineInstr, MachineBasicBlock> {
 public:
   typedef MachineMemOperand **mmo_iterator;
 
@@ -64,8 +65,10 @@ public:
     NoFlags      = 0,
     FrameSetup   = 1 << 0,              // Instruction is used as a part of
                                         // function frame setup code.
-    BundledPred  = 1 << 1,              // Instruction has bundled predecessors.
-    BundledSucc  = 1 << 2               // Instruction has bundled successors.
+    FrameDestroy = 1 << 1,              // Instruction is used as a part of
+                                        // function frame destruction code.
+    BundledPred  = 1 << 2,              // Instruction has bundled predecessors.
+    BundledSucc  = 1 << 3               // Instruction has bundled successors.
   };
 private:
   const MCInstrDesc *MCID;              // Instruction descriptor.
@@ -89,6 +92,12 @@ private:
                                         // information to AsmPrinter.
 
   uint8_t NumMemRefs;                   // Information on memory references.
+  // Note that MemRefs == nullptr,  means 'don't know', not 'no memory access'.
+  // Calling code must treat missing information conservatively.  If the number
+  // of memory operands required to be precise exceeds the maximum value of
+  // NumMemRefs - currently 256 - we remove the operands entirely. Note also
+  // that this is a non-owning reference to a shared copy on write buffer owned
+  // by the MachineFunction and created via MF.allocateMemRefsArray. 
   mmo_iterator MemRefs;
 
   DebugLoc debugLoc;                    // Source line information.
@@ -293,42 +302,46 @@ public:
   const_mop_iterator operands_end() const { return Operands + NumOperands; }
 
   iterator_range<mop_iterator> operands() {
-    return iterator_range<mop_iterator>(operands_begin(), operands_end());
+    return make_range(operands_begin(), operands_end());
   }
   iterator_range<const_mop_iterator> operands() const {
-    return iterator_range<const_mop_iterator>(operands_begin(), operands_end());
+    return make_range(operands_begin(), operands_end());
   }
   iterator_range<mop_iterator> explicit_operands() {
-    return iterator_range<mop_iterator>(
-        operands_begin(), operands_begin() + getNumExplicitOperands());
+    return make_range(operands_begin(),
+                      operands_begin() + getNumExplicitOperands());
   }
   iterator_range<const_mop_iterator> explicit_operands() const {
-    return iterator_range<const_mop_iterator>(
-        operands_begin(), operands_begin() + getNumExplicitOperands());
+    return make_range(operands_begin(),
+                      operands_begin() + getNumExplicitOperands());
   }
   iterator_range<mop_iterator> implicit_operands() {
-    return iterator_range<mop_iterator>(explicit_operands().end(),
-                                        operands_end());
+    return make_range(explicit_operands().end(), operands_end());
   }
   iterator_range<const_mop_iterator> implicit_operands() const {
-    return iterator_range<const_mop_iterator>(explicit_operands().end(),
-                                              operands_end());
+    return make_range(explicit_operands().end(), operands_end());
   }
+  /// Returns a range over all explicit operands that are register definitions.
+  /// Implicit definition are not included!
   iterator_range<mop_iterator> defs() {
-    return iterator_range<mop_iterator>(
-        operands_begin(), operands_begin() + getDesc().getNumDefs());
+    return make_range(operands_begin(),
+                      operands_begin() + getDesc().getNumDefs());
   }
+  /// \copydoc defs()
   iterator_range<const_mop_iterator> defs() const {
-    return iterator_range<const_mop_iterator>(
-        operands_begin(), operands_begin() + getDesc().getNumDefs());
+    return make_range(operands_begin(),
+                      operands_begin() + getDesc().getNumDefs());
   }
+  /// Returns a range that includes all operands that are register uses.
+  /// This may include unrelated operands which are not register uses.
   iterator_range<mop_iterator> uses() {
-    return iterator_range<mop_iterator>(
-        operands_begin() + getDesc().getNumDefs(), operands_end());
+    return make_range(operands_begin() + getDesc().getNumDefs(),
+                      operands_end());
   }
+  /// \copydoc uses()
   iterator_range<const_mop_iterator> uses() const {
-    return iterator_range<const_mop_iterator>(
-        operands_begin() + getDesc().getNumDefs(), operands_end());
+    return make_range(operands_begin() + getDesc().getNumDefs(),
+                      operands_end());
   }
 
   /// Returns the number of the operand iterator \p I points to.
@@ -339,13 +352,16 @@ public:
   /// Access to memory operands of the instruction
   mmo_iterator memoperands_begin() const { return MemRefs; }
   mmo_iterator memoperands_end() const { return MemRefs + NumMemRefs; }
+  /// Return true if we don't have any memory operands which described the the
+  /// memory access done by this instruction.  If this is true, calling code
+  /// must be conservative.    
   bool memoperands_empty() const { return NumMemRefs == 0; }
 
   iterator_range<mmo_iterator>  memoperands() {
-    return iterator_range<mmo_iterator>(memoperands_begin(), memoperands_end());
+    return make_range(memoperands_begin(), memoperands_end());
   }
   iterator_range<mmo_iterator> memoperands() const {
-    return iterator_range<mmo_iterator>(memoperands_begin(), memoperands_end());
+    return make_range(memoperands_begin(), memoperands_end());
   }
 
   /// Return true if this instruction has exactly one MachineMemOperand.
@@ -489,8 +505,8 @@ public:
   }
 
   /// Return true if this instruction is convergent.
-  /// Convergent instructions can only be moved to locations that are
-  /// control-equivalent to their initial position.
+  /// Convergent instructions can not be made control-dependent on any
+  /// additional values.
   bool isConvergent(QueryType Type = AnyInBundle) const {
     return hasProperty(MCID::Convergent, Type);
   }
@@ -897,6 +913,13 @@ public:
     return (Idx == -1) ? nullptr : &getOperand(Idx);
   }
 
+  const MachineOperand *findRegisterUseOperand(
+    unsigned Reg, bool isKill = false,
+    const TargetRegisterInfo *TRI = nullptr) const {
+    return const_cast<MachineInstr *>(this)->
+      findRegisterUseOperand(Reg, isKill, TRI);
+  }
+
   /// Returns the operand index that is a def of the specified register or
   /// -1 if it is not found. If isDead is true, defs that are not dead are
   /// skipped. If Overlap is true, then it also looks for defs that merely
@@ -1048,7 +1071,7 @@ public:
   /// Mark all subregister defs of register @p Reg with the undef flag.
   /// This function is used when we determined to have a subregister def in an
   /// otherwise undefined super register.
-  void addRegisterDefReadUndef(unsigned Reg);
+  void setRegisterDefReadUndef(unsigned Reg, bool IsUndef = true);
 
   /// We have determined MI defines a register. Make sure there is an operand
   /// defining Reg.
@@ -1094,6 +1117,9 @@ public:
   ///
   bool hasUnmodeledSideEffects() const;
 
+  /// Returns true if it is illegal to fold a load across this instruction.
+  bool isLoadFoldBarrier() const;
+
   /// Return true if all the defs of this instruction are dead.
   bool allDefsAreDead() const;
 
@@ -1159,8 +1185,11 @@ public:
     assert(NumMemRefs == NewMemRefsEnd - NewMemRefs && "Too many memrefs");
   }
 
-  /// Clear this MachineInstr's memory reference descriptor list.
-  void clearMemRefs() {
+  /// Clear this MachineInstr's memory reference descriptor list.  This resets
+  /// the memrefs to their most conservative state.  This should be used only
+  /// as a last resort since it greatly pessimizes our knowledge of the memory
+  /// access performed by the instruction.
+  void dropMemRefs() {
     MemRefs = nullptr;
     NumMemRefs = 0;
   }
@@ -1174,6 +1203,8 @@ public:
     }
   }
 
+  /// Add all implicit def and use operands to this instruction.
+  void addImplicitDefUseOperands(MachineFunction &MF);
 
 private:
   /// If this instruction is embedded into a MachineFunction, return the
@@ -1181,9 +1212,6 @@ private:
   /// return null.
   MachineRegisterInfo *getRegInfo();
 
-  /// Add all implicit def and use operands to this instruction.
-  void addImplicitDefUseOperands(MachineFunction &MF);
-
   /// Unlink all of the register operands in this instruction from their
   /// respective use lists.  This requires that the operands already be on their
   /// use lists.