Teach CodeGen's version of computeMaskedBits to understand the range metadata.

This is the CodeGen equivalent of r153747. I tested that there is not noticeable
performance difference with any combination of -O0/-O2 /-g when compiling
gcc as a single compilation unit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153817 91177308-0d34-0410-b5e6-96231b3b80d8

11 files changed, 54 insertions, 19 deletions

diff --git a/include/llvm/Analysis/ValueTracking.h b/include/llvm/Analysis/ValueTracking.h
index dfd774b916..68ea8a105d 100644
--- a/include/llvm/Analysis/ValueTracking.h
+++ b/include/llvm/Analysis/ValueTracking.h
@@ -24,7 +24,8 @@ namespace llvm {
   class APInt;
   class TargetData;
   class StringRef;
-  
+  class MDNode;
+
   /// ComputeMaskedBits - Determine which of the bits specified in Mask are
   /// known to be either zero or one and return them in the KnownZero/KnownOne
   /// bit sets.  This code only analyzes bits in Mask, in order to short-circuit
@@ -38,7 +39,9 @@ namespace llvm {
   void ComputeMaskedBits(Value *V, const APInt &Mask, APInt &KnownZero,
                          APInt &KnownOne, const TargetData *TD = 0,
                          unsigned Depth = 0);
-  
+  void computeMaskedBitsLoad(const MDNode &Ranges, const APInt &Mask,
+                             APInt &KnownZero);
+
   /// ComputeSignBit - Determine whether the sign bit is known to be zero or
   /// one.  Convenience wrapper around ComputeMaskedBits.
   void ComputeSignBit(Value *V, bool &KnownZero, bool &KnownOne,
diff --git a/include/llvm/CodeGen/MachineFunction.h b/include/llvm/CodeGen/MachineFunction.h
index fd4cac8c12..dda2dc7087 100644
--- a/include/llvm/CodeGen/MachineFunction.h
+++ b/include/llvm/CodeGen/MachineFunction.h
@@ -380,7 +380,8 @@ public:
   MachineMemOperand *getMachineMemOperand(MachinePointerInfo PtrInfo,
                                           unsigned f, uint64_t s,
                                           unsigned base_alignment,
-                                          const MDNode *TBAAInfo = 0);
+                                          const MDNode *TBAAInfo = 0,
+                                          const MDNode *Ranges = 0);
   
   /// getMachineMemOperand - Allocate a new MachineMemOperand by copying
   /// an existing one, adjusting by an offset and using the given size.
diff --git a/include/llvm/CodeGen/MachineMemOperand.h b/include/llvm/CodeGen/MachineMemOperand.h
index eed4a76a34..1ac9080b75 100644
--- a/include/llvm/CodeGen/MachineMemOperand.h
+++ b/include/llvm/CodeGen/MachineMemOperand.h
@@ -84,6 +84,7 @@ class MachineMemOperand {
   uint64_t Size;
   unsigned Flags;
   const MDNode *TBAAInfo;
+  const MDNode *Ranges;
 
 public:
   /// Flags values. These may be or'd together.
@@ -105,7 +106,8 @@ public:
   /// MachineMemOperand - Construct an MachineMemOperand object with the
   /// specified PtrInfo, flags, size, and base alignment.
   MachineMemOperand(MachinePointerInfo PtrInfo, unsigned flags, uint64_t s,
-                    unsigned base_alignment, const MDNode *TBAAInfo = 0);
+                    unsigned base_alignment, const MDNode *TBAAInfo = 0,
+                    const MDNode *Ranges = 0);
 
   const MachinePointerInfo &getPointerInfo() const { return PtrInfo; }
   
@@ -140,6 +142,9 @@ public:
   /// getTBAAInfo - Return the TBAA tag for the memory reference.
   const MDNode *getTBAAInfo() const { return TBAAInfo; }
 
+  /// getRanges - Return the range tag for the memory reference.
+  const MDNode *getRanges() const { return Ranges; }
+
   bool isLoad() const { return Flags & MOLoad; }
   bool isStore() const { return Flags & MOStore; }
   bool isVolatile() const { return Flags & MOVolatile; }
diff --git a/include/llvm/CodeGen/SelectionDAG.h b/include/llvm/CodeGen/SelectionDAG.h
index f921ca20be..aae4ee182b 100644
--- a/include/llvm/CodeGen/SelectionDAG.h
+++ b/include/llvm/CodeGen/SelectionDAG.h
@@ -654,7 +654,7 @@ public:
   SDValue getLoad(EVT VT, DebugLoc dl, SDValue Chain, SDValue Ptr,
                   MachinePointerInfo PtrInfo, bool isVolatile,
                   bool isNonTemporal, bool isInvariant, unsigned Alignment,
-                  const MDNode *TBAAInfo = 0);
+                  const MDNode *TBAAInfo = 0, const MDNode *Ranges = 0);
   SDValue getExtLoad(ISD::LoadExtType ExtType, DebugLoc dl, EVT VT,
                      SDValue Chain, SDValue Ptr, MachinePointerInfo PtrInfo,
                      EVT MemVT, bool isVolatile,
@@ -667,7 +667,8 @@ public:
                   SDValue Chain, SDValue Ptr, SDValue Offset,
                   MachinePointerInfo PtrInfo, EVT MemVT,
                   bool isVolatile, bool isNonTemporal, bool isInvariant,
-                  unsigned Alignment, const MDNode *TBAAInfo = 0);
+                  unsigned Alignment, const MDNode *TBAAInfo = 0,
+                  const MDNode *Ranges = 0);
   SDValue getLoad(ISD::MemIndexedMode AM, ISD::LoadExtType ExtType,
                   EVT VT, DebugLoc dl,
                   SDValue Chain, SDValue Ptr, SDValue Offset,
diff --git a/include/llvm/CodeGen/SelectionDAGNodes.h b/include/llvm/CodeGen/SelectionDAGNodes.h
index da3ea2ad2c..f8248b8453 100644
--- a/include/llvm/CodeGen/SelectionDAGNodes.h
+++ b/include/llvm/CodeGen/SelectionDAGNodes.h
@@ -933,6 +933,9 @@ public:
   /// Returns the TBAAInfo that describes the dereference.
   const MDNode *getTBAAInfo() const { return MMO->getTBAAInfo(); }
 
+  /// Returns the Ranges that describes the dereference.
+  const MDNode *getRanges() const { return MMO->getRanges(); }
+
   /// getMemoryVT - Return the type of the in-memory value.
   EVT getMemoryVT() const { return MemoryVT; }
 
diff --git a/lib/Analysis/ValueTracking.cpp b/lib/Analysis/ValueTracking.cpp
index 17bad941e5..1784f008d5 100644
--- a/lib/Analysis/ValueTracking.cpp
+++ b/lib/Analysis/ValueTracking.cpp
@@ -197,8 +197,8 @@ static void ComputeMaskedBitsMul(Value *Op0, Value *Op1, bool NSW,
     KnownOne.setBit(BitWidth - 1);
 }
 
-static void computeMaskedBitsLoad(const MDNode &Ranges, const APInt &Mask,
-                                  APInt &KnownZero) {
+void llvm::computeMaskedBitsLoad(const MDNode &Ranges, const APInt &Mask,
+                                 APInt &KnownZero) {
   unsigned BitWidth = Mask.getBitWidth();
   unsigned NumRanges = Ranges.getNumOperands() / 2;
   assert(NumRanges >= 1);
diff --git a/lib/CodeGen/MachineFunction.cpp b/lib/CodeGen/MachineFunction.cpp
index 64e0083017..d8c2f6a2ea 100644
--- a/lib/CodeGen/MachineFunction.cpp
+++ b/lib/CodeGen/MachineFunction.cpp
@@ -195,9 +195,10 @@ MachineFunction::DeleteMachineBasicBlock(MachineBasicBlock *MBB) {
 MachineMemOperand *
 MachineFunction::getMachineMemOperand(MachinePointerInfo PtrInfo, unsigned f,
                                       uint64_t s, unsigned base_alignment,
-                                      const MDNode *TBAAInfo) {
+                                      const MDNode *TBAAInfo,
+                                      const MDNode *Ranges) {
   return new (Allocator) MachineMemOperand(PtrInfo, f, s, base_alignment,
-                                           TBAAInfo);
+                                           TBAAInfo, Ranges);
 }
 
 MachineMemOperand *
diff --git a/lib/CodeGen/MachineInstr.cpp b/lib/CodeGen/MachineInstr.cpp
index 43af1addca..e553a0463a 100644
--- a/lib/CodeGen/MachineInstr.cpp
+++ b/lib/CodeGen/MachineInstr.cpp
@@ -381,10 +381,11 @@ MachinePointerInfo MachinePointerInfo::getStack(int64_t Offset) {
 
 MachineMemOperand::MachineMemOperand(MachinePointerInfo ptrinfo, unsigned f,
                                      uint64_t s, unsigned int a,
-                                     const MDNode *TBAAInfo)
+                                     const MDNode *TBAAInfo,
+                                     const MDNode *Ranges)
   : PtrInfo(ptrinfo), Size(s),
     Flags((f & ((1 << MOMaxBits) - 1)) | ((Log2_32(a) + 1) << MOMaxBits)),
-    TBAAInfo(TBAAInfo) {
+    TBAAInfo(TBAAInfo), Ranges(Ranges) {
   assert((PtrInfo.V == 0 || isa<PointerType>(PtrInfo.V->getType())) &&
          "invalid pointer value");
   assert(getBaseAlignment() == a && "Alignment is not a power of 2!");
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index e3a7305f00..48f8f773be 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -1889,11 +1889,13 @@ void SelectionDAG::ComputeMaskedBits(SDValue Op, const APInt &Mask,
     return;
   }
   case ISD::LOAD: {
+    LoadSDNode *LD = cast<LoadSDNode>(Op);
     if (ISD::isZEXTLoad(Op.getNode())) {
-      LoadSDNode *LD = cast<LoadSDNode>(Op);
       EVT VT = LD->getMemoryVT();
       unsigned MemBits = VT.getScalarType().getSizeInBits();
       KnownZero |= APInt::getHighBitsSet(BitWidth, BitWidth - MemBits) & Mask;
+    } else if (const MDNode *Ranges = LD->getRanges()) {
+      computeMaskedBitsLoad(*Ranges, Mask, KnownZero);
     }
     return;
   }
@@ -4170,7 +4172,8 @@ SelectionDAG::getLoad(ISD::MemIndexedMode AM, ISD::LoadExtType ExtType,
                       SDValue Ptr, SDValue Offset,
                       MachinePointerInfo PtrInfo, EVT MemVT,
                       bool isVolatile, bool isNonTemporal, bool isInvariant,
-                      unsigned Alignment, const MDNode *TBAAInfo) {
+                      unsigned Alignment, const MDNode *TBAAInfo,
+                      const MDNode *Ranges) {
   assert(Chain.getValueType() == MVT::Other && 
         "Invalid chain type");
   if (Alignment == 0)  // Ensure that codegen never sees alignment 0
@@ -4192,7 +4195,7 @@ SelectionDAG::getLoad(ISD::MemIndexedMode AM, ISD::LoadExtType ExtType,
   MachineFunction &MF = getMachineFunction();
   MachineMemOperand *MMO =
     MF.getMachineMemOperand(PtrInfo, Flags, MemVT.getStoreSize(), Alignment,
-                            TBAAInfo);
+                            TBAAInfo, Ranges);
   return getLoad(AM, ExtType, VT, dl, Chain, Ptr, Offset, MemVT, MMO);
 }
 
@@ -4248,11 +4251,12 @@ SDValue SelectionDAG::getLoad(EVT VT, DebugLoc dl,
                               MachinePointerInfo PtrInfo,
                               bool isVolatile, bool isNonTemporal,
                               bool isInvariant, unsigned Alignment, 
-                              const MDNode *TBAAInfo) {
+                              const MDNode *TBAAInfo,
+                              const MDNode *Ranges) {
   SDValue Undef = getUNDEF(Ptr.getValueType());
   return getLoad(ISD::UNINDEXED, ISD::NON_EXTLOAD, VT, dl, Chain, Ptr, Undef,
-                 PtrInfo, VT, isVolatile, isNonTemporal, isInvariant, Alignment, 
-                 TBAAInfo);
+                 PtrInfo, VT, isVolatile, isNonTemporal, isInvariant, Alignment,
+                 TBAAInfo, Ranges);
 }
 
 SDValue SelectionDAG::getExtLoad(ISD::LoadExtType ExtType, DebugLoc dl, EVT VT,
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 49f0431e30..84a8b7b11b 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -3215,6 +3215,7 @@ void SelectionDAGBuilder::visitLoad(const LoadInst &I) {
   bool isInvariant = I.getMetadata("invariant.load") != 0;
   unsigned Alignment = I.getAlignment();
   const MDNode *TBAAInfo = I.getMetadata(LLVMContext::MD_tbaa);
+  const MDNode *Ranges = I.getMetadata(LLVMContext::MD_range);
 
   SmallVector<EVT, 4> ValueVTs;
   SmallVector<uint64_t, 4> Offsets;
@@ -3262,7 +3263,8 @@ void SelectionDAGBuilder::visitLoad(const LoadInst &I) {
                             DAG.getConstant(Offsets[i], PtrVT));
     SDValue L = DAG.getLoad(ValueVTs[i], getCurDebugLoc(), Root,
                             A, MachinePointerInfo(SV, Offsets[i]), isVolatile,
-                            isNonTemporal, isInvariant, Alignment, TBAAInfo);
+                            isNonTemporal, isInvariant, Alignment, TBAAInfo,
+                            Ranges);
 
     Values[i] = L;
     Chains[ChainI] = L.getValue(1);
diff --git a/test/CodeGen/X86/pr12360.ll b/test/CodeGen/X86/pr12360.ll
new file mode 100644
index 0000000000..c0af432cc8
--- /dev/null
+++ b/test/CodeGen/X86/pr12360.ll
@@ -0,0 +1,14 @@
+; RUN: llc < %s -march=x86-64 | FileCheck %s
+
+define zeroext i1 @f1(i8* %x) {
+entry:
+  %0 = load i8* %x, align 1, !range !0
+  %tobool = trunc i8 %0 to i1
+  ret i1 %tobool
+}
+
+; CHECK: f1:
+; CHECK: movb	(%rdi), %al
+; CHECK-NEXT: ret
+
+!0 = metadata !{i8 0, i8 2}