Merge commit 'a662a9862501fc86904e90054f7c1519101d9126'

Conflicts:
	include/llvm/CodeGen/IntrinsicLowering.h
	include/llvm/MC/MCAssembler.h
	include/llvm/MC/MCObjectStreamer.h
	lib/LLVMBuild.txt
	lib/Linker/LinkArchives.cpp
	lib/MC/MCAssembler.cpp
	lib/MC/MCELFStreamer.cpp
	lib/MC/MCParser/AsmParser.cpp
	lib/MC/MCPureStreamer.cpp
	lib/MC/WinCOFFStreamer.cpp
	lib/Makefile
	lib/Support/Unix/Memory.inc
	lib/Support/Unix/Process.inc
	lib/Support/Unix/Program.inc
	lib/Target/ARM/ARM.h
	lib/Target/ARM/ARMFastISel.cpp
	lib/Target/ARM/ARMISelLowering.cpp
	lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp
	lib/Target/Mips/MipsInstrFPU.td
	lib/Target/X86/CMakeLists.txt
	lib/Target/X86/X86ISelLowering.cpp
	lib/Target/X86/X86TargetMachine.cpp
	lib/Target/X86/X86TargetObjectFile.cpp
	lib/Transforms/InstCombine/InstCombineCalls.cpp
	test/CodeGen/X86/fast-isel-x86-64.ll
	tools/llc/llc.cpp
	tools/lto/LTOModule.cpp
	utils/TableGen/EDEmitter.cpp

1 files changed, 78 insertions, 11 deletions

diff --git a/lib/Transforms/InstCombine/InstructionCombining.cpp b/lib/Transforms/InstCombine/InstructionCombining.cpp
index 9da58d0e71..dc7fe5cf6b 100644
--- a/lib/Transforms/InstCombine/InstructionCombining.cpp
+++ b/lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -43,8 +43,8 @@
 #include "llvm/Analysis/ConstantFolding.h"
 #include "llvm/Analysis/InstructionSimplify.h"
 #include "llvm/Analysis/MemoryBuiltins.h"
-#include "llvm/DataLayout.h"
-#include "llvm/IntrinsicInst.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/IntrinsicInst.h"
 #include "llvm/Support/CFG.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
@@ -516,8 +516,8 @@ Value *InstCombiner::dyn_castNegVal(Value *V) const {
 // instruction if the LHS is a constant negative zero (which is the 'negate'
 // form).
 //
-Value *InstCombiner::dyn_castFNegVal(Value *V) const {
-  if (BinaryOperator::isFNeg(V))
+Value *InstCombiner::dyn_castFNegVal(Value *V, bool IgnoreZeroSign) const {
+  if (BinaryOperator::isFNeg(V, IgnoreZeroSign))
     return BinaryOperator::getFNegArgument(V);
 
   // Constants can be considered to be negated values if they can be folded.
@@ -1309,17 +1309,15 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) {
   /// into a gep of the original struct.  This is important for SROA and alias
   /// analysis of unions.  If "A" is also a bitcast, wait for A/X to be merged.
   if (BitCastInst *BCI = dyn_cast<BitCastInst>(PtrOp)) {
+    APInt Offset(TD ? TD->getPointerSizeInBits() : 1, 0);
     if (TD &&
-        !isa<BitCastInst>(BCI->getOperand(0)) && GEP.hasAllConstantIndices() &&
+        !isa<BitCastInst>(BCI->getOperand(0)) &&
+        GEP.accumulateConstantOffset(*TD, Offset) &&
         StrippedPtrTy->getAddressSpace() == GEP.getPointerAddressSpace()) {
 
-      // Determine how much the GEP moves the pointer.
-      SmallVector<Value*, 8> Ops(GEP.idx_begin(), GEP.idx_end());
-      int64_t Offset = TD->getIndexedOffset(GEP.getPointerOperandType(), Ops);
-
       // If this GEP instruction doesn't move the pointer, just replace the GEP
       // with a bitcast of the real input to the dest type.
-      if (Offset == 0) {
+      if (!Offset) {
         // If the bitcast is of an allocation, and the allocation will be
         // converted to match the type of the cast, don't touch this.
         if (isa<AllocaInst>(BCI->getOperand(0)) ||
@@ -1343,7 +1341,7 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) {
       SmallVector<Value*, 8> NewIndices;
       Type *InTy =
         cast<PointerType>(BCI->getOperand(0)->getType())->getElementType();
-      if (FindElementAtOffset(InTy, Offset, NewIndices)) {
+      if (FindElementAtOffset(InTy, Offset.getSExtValue(), NewIndices)) {
         Value *NGEP = GEP.isInBounds() ?
           Builder->CreateInBoundsGEP(BCI->getOperand(0), NewIndices) :
           Builder->CreateGEP(BCI->getOperand(0), NewIndices);
@@ -1477,6 +1475,62 @@ Instruction *InstCombiner::visitAllocSite(Instruction &MI) {
   return 0;
 }
 
+/// \brief Move the call to free before a NULL test.
+///
+/// Check if this free is accessed after its argument has been test
+/// against NULL (property 0).
+/// If yes, it is legal to move this call in its predecessor block.
+///
+/// The move is performed only if the block containing the call to free
+/// will be removed, i.e.:
+/// 1. it has only one predecessor P, and P has two successors
+/// 2. it contains the call and an unconditional branch
+/// 3. its successor is the same as its predecessor's successor
+///
+/// The profitability is out-of concern here and this function should
+/// be called only if the caller knows this transformation would be
+/// profitable (e.g., for code size).
+static Instruction *
+tryToMoveFreeBeforeNullTest(CallInst &FI) {
+  Value *Op = FI.getArgOperand(0);
+  BasicBlock *FreeInstrBB = FI.getParent();
+  BasicBlock *PredBB = FreeInstrBB->getSinglePredecessor();
+
+  // Validate part of constraint #1: Only one predecessor
+  // FIXME: We can extend the number of predecessor, but in that case, we
+  //        would duplicate the call to free in each predecessor and it may
+  //        not be profitable even for code size.
+  if (!PredBB)
+    return 0;
+
+  // Validate constraint #2: Does this block contains only the call to
+  //                         free and an unconditional branch?
+  // FIXME: We could check if we can speculate everything in the
+  //        predecessor block
+  if (FreeInstrBB->size() != 2)
+    return 0;
+  BasicBlock *SuccBB;
+  if (!match(FreeInstrBB->getTerminator(), m_UnconditionalBr(SuccBB)))
+    return 0;
+
+  // Validate the rest of constraint #1 by matching on the pred branch.
+  TerminatorInst *TI = PredBB->getTerminator();
+  BasicBlock *TrueBB, *FalseBB;
+  ICmpInst::Predicate Pred;
+  if (!match(TI, m_Br(m_ICmp(Pred, m_Specific(Op), m_Zero()), TrueBB, FalseBB)))
+    return 0;
+  if (Pred != ICmpInst::ICMP_EQ && Pred != ICmpInst::ICMP_NE)
+    return 0;
+
+  // Validate constraint #3: Ensure the null case just falls through.
+  if (SuccBB != (Pred == ICmpInst::ICMP_EQ ? TrueBB : FalseBB))
+    return 0;
+  assert(FreeInstrBB == (Pred == ICmpInst::ICMP_EQ ? FalseBB : TrueBB) &&
+         "Broken CFG: missing edge from predecessor to successor");
+
+  FI.moveBefore(TI);
+  return &FI;
+}
 
 
 Instruction *InstCombiner::visitFree(CallInst &FI) {
@@ -1495,6 +1549,16 @@ Instruction *InstCombiner::visitFree(CallInst &FI) {
   if (isa<ConstantPointerNull>(Op))
     return EraseInstFromFunction(FI);
 
+  // If we optimize for code size, try to move the call to free before the null
+  // test so that simplify cfg can remove the empty block and dead code
+  // elimination the branch. I.e., helps to turn something like:
+  // if (foo) free(foo);
+  // into
+  // free(foo);
+  if (MinimizeSize)
+    if (Instruction *I = tryToMoveFreeBeforeNullTest(FI))
+      return I;
+
   return 0;
 }
 
@@ -2395,6 +2459,9 @@ public:
 bool InstCombiner::runOnFunction(Function &F) {
   TD = getAnalysisIfAvailable<DataLayout>();
   TLI = &getAnalysis<TargetLibraryInfo>();
+  // Minimizing size?
+  MinimizeSize = F.getAttributes().hasAttribute(AttributeSet::FunctionIndex,
+                                                Attribute::MinSize);
 
   /// Builder - This is an IRBuilder that automatically inserts new
   /// instructions into the worklist when they are created.