Rework the SelectionDAG-based implementations of SimplifyDemandedBits
and ComputeMaskedBits to match the new improved versions in instcombine.
Tested against all of multisource/benchmarks on ppc.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26238 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/Sparc/SparcISelDAGToDAG.cpp b/lib/Target/Sparc/SparcISelDAGToDAG.cpp
index 8671b60..d80c006 100644
--- a/lib/Target/Sparc/SparcISelDAGToDAG.cpp
+++ b/lib/Target/Sparc/SparcISelDAGToDAG.cpp
@@ -98,11 +98,14 @@
SparcTargetLowering(TargetMachine &TM);
virtual SDOperand LowerOperation(SDOperand Op, SelectionDAG &DAG);
- /// isMaskedValueZeroForTargetNode - Return true if 'Op & Mask' is known to
- /// be zero. Op is expected to be a target specific node. Used by DAG
- /// combiner.
- virtual bool isMaskedValueZeroForTargetNode(const SDOperand &Op,
- uint64_t Mask) const;
+ /// computeMaskedBitsForTargetNode - Determine which of the bits specified
+ /// in Mask are known to be either zero or one and return them in the
+ /// KnownZero/KnownOne bitsets.
+ virtual void computeMaskedBitsForTargetNode(const SDOperand Op,
+ uint64_t Mask,
+ uint64_t &KnownZero,
+ uint64_t &KnownOne,
+ unsigned Depth = 0) const;
virtual std::vector<SDOperand>
LowerArguments(Function &F, SelectionDAG &DAG);
@@ -246,20 +249,30 @@
/// isMaskedValueZeroForTargetNode - Return true if 'Op & Mask' is known to
/// be zero. Op is expected to be a target specific node. Used by DAG
/// combiner.
-bool SparcTargetLowering::
-isMaskedValueZeroForTargetNode(const SDOperand &Op, uint64_t Mask) const {
+void SparcTargetLowering::computeMaskedBitsForTargetNode(const SDOperand Op,
+ uint64_t Mask,
+ uint64_t &KnownZero,
+ uint64_t &KnownOne,
+ unsigned Depth) const {
+ uint64_t KnownZero2, KnownOne2;
+ KnownZero = KnownOne = 0; // Don't know anything.
+
switch (Op.getOpcode()) {
- default: return false;
+ default: break;
case SPISD::SELECT_ICC:
case SPISD::SELECT_FCC:
- assert(MVT::isInteger(Op.getValueType()) && "Not an integer select!");
- // These operations are masked zero if both the left and the right are zero.
- return MaskedValueIsZero(Op.getOperand(0), Mask) &&
- MaskedValueIsZero(Op.getOperand(1), Mask);
+ ComputeMaskedBits(Op.getOperand(1), Mask, KnownZero, KnownOne, Depth+1);
+ ComputeMaskedBits(Op.getOperand(0), Mask, KnownZero2, KnownOne2, Depth+1);
+ assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
+ assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?");
+
+ // Only known if known in both the LHS and RHS.
+ KnownOne &= KnownOne2;
+ KnownZero &= KnownZero2;
+ break;
}
}
-
/// LowerArguments - V8 uses a very simple ABI, where all values are passed in
/// either one or two GPRs, including FP values. TODO: we should pass FP values
/// in FP registers for fastcc functions.
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index adaa986..3e0a210 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -2035,19 +2035,23 @@
}
}
-bool X86TargetLowering::isMaskedValueZeroForTargetNode(const SDOperand &Op,
- uint64_t Mask) const {
+void X86TargetLowering::computeMaskedBitsForTargetNode(const SDOperand Op,
+ uint64_t Mask,
+ uint64_t &KnownZero,
+ uint64_t &KnownOne,
+ unsigned Depth) const {
unsigned Opc = Op.getOpcode();
+ KnownZero = KnownOne = 0; // Don't know anything.
switch (Opc) {
default:
assert(Opc >= ISD::BUILTIN_OP_END && "Expected a target specific node");
break;
- case X86ISD::SETCC: return (Mask & 1) == 0;
+ case X86ISD::SETCC:
+ KnownZero |= (MVT::getIntVTBitMask(Op.getValueType()) ^ 1ULL);
+ break;
}
-
- return false;
}
std::vector<unsigned> X86TargetLowering::
diff --git a/lib/Target/X86/X86ISelLowering.h b/lib/Target/X86/X86ISelLowering.h
index 88d8e6c..dc1a13c 100644
--- a/lib/Target/X86/X86ISelLowering.h
+++ b/lib/Target/X86/X86ISelLowering.h
@@ -218,12 +218,15 @@
/// DAG node.
virtual const char *getTargetNodeName(unsigned Opcode) const;
- /// isMaskedValueZeroForTargetNode - Return true if 'Op & Mask' is known to
- /// be zero. Op is expected to be a target specific node. Used by DAG
- /// combiner.
- virtual bool isMaskedValueZeroForTargetNode(const SDOperand &Op,
- uint64_t Mask) const;
-
+ /// computeMaskedBitsForTargetNode - Determine which of the bits specified
+ /// in Mask are known to be either zero or one and return them in the
+ /// KnownZero/KnownOne bitsets.
+ virtual void computeMaskedBitsForTargetNode(const SDOperand Op,
+ uint64_t Mask,
+ uint64_t &KnownZero,
+ uint64_t &KnownOne,
+ unsigned Depth = 0) const;
+
SDOperand getReturnAddressFrameIndex(SelectionDAG &DAG);
std::vector<unsigned>