From 78eaf05fa72bd1376c0923329953fec20671b6b6 Mon Sep 17 00:00:00 2001
From: Jakob Stoklund Olesen <stoklund@2pi.dk>
Date: Tue, 18 Dec 2012 20:59:41 +0000
Subject: [PATCH] Tighten up the splice() API for bundled instructions.

Remove the instr_iterator versions of the splice() functions. It doesn't
seem useful to be able to splice sequences of instructions that don't
consist of full bundles.

The normal splice functions that take MBB::iterator arguments are not
changed, and they can move whole bundles around without any problems.

llvm-svn: 170456
---
 llvm/include/llvm/CodeGen/MachineBasicBlock.h | 31 ++++++++++++++-------------
 llvm/lib/CodeGen/MachineBasicBlock.cpp        | 13 -----------
 2 files changed, 16 insertions(+), 28 deletions(-)

diff --git a/llvm/include/llvm/CodeGen/MachineBasicBlock.h b/llvm/include/llvm/CodeGen/MachineBasicBlock.h
index 0a12de3..1225c8a9 100644
--- a/llvm/include/llvm/CodeGen/MachineBasicBlock.h
+++ b/llvm/include/llvm/CodeGen/MachineBasicBlock.h
@@ -524,23 +524,24 @@ public:
     Insts.clear();
   }
 
-  /// splice - Take an instruction from MBB 'Other' at the position From,
-  /// and insert it into this MBB right before 'where'.
-  void splice(instr_iterator where, MachineBasicBlock *Other,
-              instr_iterator From) {
-    Insts.splice(where, Other->Insts, From);
+  /// Take an instruction from MBB 'Other' at the position From, and insert it
+  /// into this MBB right before 'Where'.
+  ///
+  /// If From points to a bundle of instructions, the whole bundle is moved.
+  void splice(iterator Where, MachineBasicBlock *Other, iterator From) {
+    // The range splice() doesn't allow noop moves, but this one does.
+    if (Where != From)
+      splice(Where, Other, From, llvm::next(From));
   }
-  void splice(iterator where, MachineBasicBlock *Other, iterator From);
 
-  /// splice - Take a block of instructions from MBB 'Other' in the range [From,
-  /// To), and insert them into this MBB right before 'where'.
-  void splice(instr_iterator where, MachineBasicBlock *Other, instr_iterator From,
-              instr_iterator To) {
-    Insts.splice(where, Other->Insts, From, To);
-  }
-  void splice(iterator where, MachineBasicBlock *Other, iterator From,
-              iterator To) {
-    Insts.splice(where.getInstrIterator(), Other->Insts,
+  /// Take a block of instructions from MBB 'Other' in the range [From, To),
+  /// and insert them into this MBB right before 'Where'.
+  ///
+  /// The instruction at 'Where' must not be included in the range of
+  /// instructions to move.
+  void splice(iterator Where, MachineBasicBlock *Other,
+              iterator From, iterator To) {
+    Insts.splice(Where.getInstrIterator(), Other->Insts,
                  From.getInstrIterator(), To.getInstrIterator());
   }
 
diff --git a/llvm/lib/CodeGen/MachineBasicBlock.cpp b/llvm/lib/CodeGen/MachineBasicBlock.cpp
index 027f777..207f215 100644
--- a/llvm/lib/CodeGen/MachineBasicBlock.cpp
+++ b/llvm/lib/CodeGen/MachineBasicBlock.cpp
@@ -826,19 +826,6 @@ MachineBasicBlock::insert(instr_iterator I, MachineInstr *MI) {
   return Insts.insert(I, MI);
 }
 
-void MachineBasicBlock::splice(MachineBasicBlock::iterator where,
-                               MachineBasicBlock *Other,
-                               MachineBasicBlock::iterator From) {
-  if (From->isBundle()) {
-    MachineBasicBlock::iterator To = llvm::next(From);
-    Insts.splice(where.getInstrIterator(), Other->Insts,
-                 From.getInstrIterator(), To.getInstrIterator());
-    return;
-  }
-
-  Insts.splice(where.getInstrIterator(), Other->Insts, From.getInstrIterator());
-}
-
 /// removeFromParent - This method unlinks 'this' from the containing function,
 /// and returns it, but does not delete it.
 MachineBasicBlock *MachineBasicBlock::removeFromParent() {
-- 
2.7.4