4 files changed, 23 insertions, 2 deletions
diff --git a/llvm/include/llvm/CodeGen/Passes.h b/llvm/include/llvm/CodeGen/Passes.h
index 8275b0fb60a..3b0957202b7 100644
--- a/llvm/include/llvm/CodeGen/Passes.h
+++ b/llvm/include/llvm/CodeGen/Passes.h
@@ -599,6 +599,9 @@ namespace llvm {
   /// \brief This pass lays out funclets contiguously.
   extern char &FuncletLayoutID;
 
+  /// \brief This pass implements the "patchable-function" attribute.
+  extern char &PatchableFunctionID;
+
   /// createStackProtectorPass - This pass adds stack protectors to functions.
   ///
   FunctionPass *createStackProtectorPass(const TargetMachine *TM);
diff --git a/llvm/include/llvm/InitializePasses.h b/llvm/include/llvm/InitializePasses.h
index 278da515b60..047e3af3a64 100644
--- a/llvm/include/llvm/InitializePasses.h
+++ b/llvm/include/llvm/InitializePasses.h
@@ -329,6 +329,7 @@ void initializeLoopLoadEliminationPass(PassRegistry&);
 void initializeFunctionImportPassPass(PassRegistry &);
 void initializeLoopVersioningPassPass(PassRegistry &);
 void initializeWholeProgramDevirtPass(PassRegistry &);
+void initializePatchableFunctionPass(PassRegistry &);
 }
 
 #endif
diff --git a/llvm/include/llvm/Target/Target.td b/llvm/include/llvm/Target/Target.td
index 7c55442f479..f7fe904f61f 100644
--- a/llvm/include/llvm/Target/Target.td
+++ b/llvm/include/llvm/Target/Target.td
@@ -929,6 +929,14 @@ def FAULTING_LOAD_OP : Instruction {
   let usesCustomInserter = 1;
   let mayLoad = 1;
 }
+def PATCHABLE_OP : Instruction {
+  let OutOperandList = (outs unknown:$dst);
+  let InOperandList = (ins variable_ops);
+  let usesCustomInserter = 1;
+  let mayLoad = 1;
+  let mayStore = 1;
+  let hasSideEffects = 1;
+}
 
 // Generic opcodes used in GlobalISel.
 include "llvm/Target/GenericOpcodes.td"
diff --git a/llvm/include/llvm/Target/TargetOpcodes.def b/llvm/include/llvm/Target/TargetOpcodes.def
index 704c6dcd8dc..d9c2e9eca7a 100644
--- a/llvm/include/llvm/Target/TargetOpcodes.def
+++ b/llvm/include/llvm/Target/TargetOpcodes.def
@@ -133,16 +133,25 @@ HANDLE_TARGET_OPCODE(LOCAL_ESCAPE, 21)
 /// comparisons into existing memory operations.
 HANDLE_TARGET_OPCODE(FAULTING_LOAD_OP, 22)
 
+/// Wraps a machine instruction to add patchability constraints.  An
+/// instruction wrapped in PATCHABLE_OP has to either have a minimum
+/// size or be preceded with a nop of that size.  The first operand is
+/// an immediate denoting the minimum size of the instruction, the
+/// second operand is an immediate denoting the opcode of the original
+/// instruction.  The rest of the operands are the operands of the
+/// original instruction.
+HANDLE_TARGET_OPCODE(PATCHABLE_OP, 23)
+
 /// The following generic opcodes are not supposed to appear after ISel.
 /// This is something we might want to relax, but for now, this is convenient
 /// to produce diagnostics.
 
 /// Generic ADD instruction. This is an integer add.
-HANDLE_TARGET_OPCODE(G_ADD, 23)
+HANDLE_TARGET_OPCODE(G_ADD, 24)
 HANDLE_TARGET_OPCODE_MARKER(PRE_ISEL_GENERIC_OPCODE_START, G_ADD)
 
 /// Generic BRANCH instruction. This is an unconditional branch.
-HANDLE_TARGET_OPCODE(G_BR, 24)
+HANDLE_TARGET_OPCODE(G_BR, 25)
 
 // TODO: Add more generic opcodes as we move along.