Replace r169459 with something safer. Rather than having computeMaskedBits to
understand target implementation of any_extend / extload, just generate
zero_extend in place of any_extend for liveouts when the target knows the
zero_extend will be implicit (e.g. ARM ldrb / ldrh) or folded (e.g. x86 movz).
rdar://12771555
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169536 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index c0a7853..32235b9 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -9462,6 +9462,27 @@
return MVT::Other;
}
+bool ARMTargetLowering::isZExtFree(SDValue Val, EVT VT2) const {
+ if (Val.getOpcode() != ISD::LOAD)
+ return false;
+
+ EVT VT1 = Val.getValueType();
+ if (!VT1.isSimple() || !VT1.isInteger() ||
+ !VT2.isSimple() || !VT2.isInteger())
+ return false;
+
+ switch (VT1.getSimpleVT().SimpleTy) {
+ default: break;
+ case MVT::i1:
+ case MVT::i8:
+ case MVT::i16:
+ // 8-bit and 16-bit loads implicitly zero-extend to 32-bits.
+ return true;
+ }
+
+ return false;
+}
+
static bool isLegalT1AddressImmediate(int64_t V, EVT VT) {
if (V < 0)
return false;
@@ -9878,36 +9899,6 @@
}
}
-void ARMTargetLowering::computeMaskedBitsForAnyExtend(const SDValue Op,
- APInt &KnownZero,
- APInt &KnownOne,
- const SelectionDAG &DAG,
- unsigned Depth) const {
- unsigned BitWidth = Op.getValueType().getScalarType().getSizeInBits();
- if (Op.getOpcode() == ISD::ANY_EXTEND) {
- // Implemented as a zero_extend.
- EVT InVT = Op.getOperand(0).getValueType();
- unsigned InBits = InVT.getScalarType().getSizeInBits();
- KnownZero = KnownZero.trunc(InBits);
- KnownOne = KnownOne.trunc(InBits);
- DAG.ComputeMaskedBits(Op.getOperand(0), KnownZero, KnownOne, Depth+1);
- KnownZero = KnownZero.zext(BitWidth);
- KnownOne = KnownOne.zext(BitWidth);
- APInt NewBits = APInt::getHighBitsSet(BitWidth, BitWidth - InBits);
- KnownZero |= NewBits;
- return;
- } else if (ISD::isEXTLoad(Op.getNode())) {
- // Implemented as zextloads.
- LoadSDNode *LD = cast<LoadSDNode>(Op);
- EVT VT = LD->getMemoryVT();
- unsigned MemBits = VT.getScalarType().getSizeInBits();
- KnownZero |= APInt::getHighBitsSet(BitWidth, BitWidth - MemBits);
- return;
- }
-
- assert(0 && "Expecting an ANY_EXTEND or extload!");
-}
-
//===----------------------------------------------------------------------===//
// ARM Inline Assembly Support
//===----------------------------------------------------------------------===//