Merging r259381:

[oota-llvm.git] / lib / Target / SystemZ / SystemZISelLowering.cpp

diff --git a/lib/Target/SystemZ/SystemZISelLowering.cpp b/lib/Target/SystemZ/SystemZISelLowering.cpp
index f598bc0189d85693cf576a1528e11468915db1d4..b0a6127646364d219a21c37141f7e752be384163 100644 (file)
--- a/lib/Target/SystemZ/SystemZISelLowering.cpp
+++ b/lib/Target/SystemZ/SystemZISelLowering.cpp
@@ -775,9 +775,7 @@ bool SystemZTargetLowering::allowTruncateForTailCall(Type *FromType,
 }
 
 bool SystemZTargetLowering::mayBeEmittedAsTailCall(CallInst *CI) const {
-  if (!CI->isTailCall())
-    return false;
-  return true;
+  return CI->isTailCall();
 }
 
 // We do not yet support 128-bit single-element vector types.  If the user
@@ -1605,8 +1603,8 @@ static void adjustSubwordCmp(SelectionDAG &DAG, SDLoc DL, Comparison &C) {
   } else if (Load->getExtensionType() == ISD::ZEXTLOAD) {
     if (Value > Mask)
       return;
-    assert(C.ICmpType == SystemZICMP::Any &&
-           "Signedness shouldn't matter here.");
+    // If the constant is in range, we can use any comparison.
+    C.ICmpType = SystemZICMP::Any;
   } else
     return;
 
@@ -1851,7 +1849,7 @@ static unsigned getTestUnderMaskCond(unsigned BitSize, unsigned CCMask,
     if (CCMask == SystemZ::CCMASK_CMP_NE)
       return SystemZ::CCMASK_TM_SOME_1;
   }
-  if (EffectivelyUnsigned && CmpVal <= Low) {
+  if (EffectivelyUnsigned && CmpVal > 0 && CmpVal <= Low) {
     if (CCMask == SystemZ::CCMASK_CMP_LT)
       return SystemZ::CCMASK_TM_ALL_0;
     if (CCMask == SystemZ::CCMASK_CMP_GE)
@@ -2741,17 +2739,37 @@ SDValue SystemZTargetLowering::lowerVACOPY(SDValue Op,
 
 SDValue SystemZTargetLowering::
 lowerDYNAMIC_STACKALLOC(SDValue Op, SelectionDAG &DAG) const {
+  const TargetFrameLowering *TFI = Subtarget.getFrameLowering();
+  bool RealignOpt = !DAG.getMachineFunction().getFunction()->
+    hasFnAttribute("no-realign-stack");
+
   SDValue Chain = Op.getOperand(0);
   SDValue Size  = Op.getOperand(1);
+  SDValue Align = Op.getOperand(2);
   SDLoc DL(Op);
 
+  // If user has set the no alignment function attribute, ignore
+  // alloca alignments.
+  uint64_t AlignVal = (RealignOpt ?
+                       dyn_cast<ConstantSDNode>(Align)->getZExtValue() : 0);
+
+  uint64_t StackAlign = TFI->getStackAlignment();
+  uint64_t RequiredAlign = std::max(AlignVal, StackAlign);
+  uint64_t ExtraAlignSpace = RequiredAlign - StackAlign;
+
   unsigned SPReg = getStackPointerRegisterToSaveRestore();
+  SDValue NeededSpace = Size;
 
   // Get a reference to the stack pointer.
   SDValue OldSP = DAG.getCopyFromReg(Chain, DL, SPReg, MVT::i64);
 
+  // Add extra space for alignment if needed.
+  if (ExtraAlignSpace)
+    NeededSpace = DAG.getNode(ISD::ADD, DL, MVT::i64, NeededSpace,
+                              DAG.getConstant(ExtraAlignSpace, DL, MVT::i64)); 
+
   // Get the new stack pointer value.
-  SDValue NewSP = DAG.getNode(ISD::SUB, DL, MVT::i64, OldSP, Size);
+  SDValue NewSP = DAG.getNode(ISD::SUB, DL, MVT::i64, OldSP, NeededSpace);
 
   // Copy the new stack pointer back.
   Chain = DAG.getCopyToReg(Chain, DL, SPReg, NewSP);
@@ -2762,6 +2780,16 @@ lowerDYNAMIC_STACKALLOC(SDValue Op, SelectionDAG &DAG) const {
   SDValue ArgAdjust = DAG.getNode(SystemZISD::ADJDYNALLOC, DL, MVT::i64);
   SDValue Result = DAG.getNode(ISD::ADD, DL, MVT::i64, NewSP, ArgAdjust);
 
+  // Dynamically realign if needed.
+  if (RequiredAlign > StackAlign) {
+    Result =
+      DAG.getNode(ISD::ADD, DL, MVT::i64, Result,
+                  DAG.getConstant(ExtraAlignSpace, DL, MVT::i64));
+    Result =
+      DAG.getNode(ISD::AND, DL, MVT::i64, Result,
+                  DAG.getConstant(~(RequiredAlign - 1), DL, MVT::i64));
+  }
+
   SDValue Ops[2] = { Result, Chain };
   return DAG.getMergeValues(Ops, DL);
 }