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[XCore] Provide information about known zero bits of resource instructions.

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202393 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Richard Osborne
2014-02-27 13:20:06 +00:00
parent 9aef4445a3
commit ef174f733a
2 changed files with 80 additions and 0 deletions
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lib/Target/XCore/XCoreISelLowering.cpp
+28
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@@ -1770,6 +1770,34 @@ void XCoreTargetLowering::computeMaskedBitsForTargetNode(const SDValue Op,
KnownZero.getBitWidth() - 1);
}
break;
case ISD::INTRINSIC_W_CHAIN:
{
unsigned IntNo = cast<ConstantSDNode>(Op.getOperand(1))->getZExtValue();
switch (IntNo) {
case Intrinsic::xcore_getts:
// High bits are known to be zero.
KnownZero = APInt::getHighBitsSet(KnownZero.getBitWidth(),
KnownZero.getBitWidth() - 16);
break;
case Intrinsic::xcore_int:
case Intrinsic::xcore_inct:
// High bits are known to be zero.
KnownZero = APInt::getHighBitsSet(KnownZero.getBitWidth(),
KnownZero.getBitWidth() - 8);
break;
case Intrinsic::xcore_testct:
// Result is either 0 or 1.
KnownZero = APInt::getHighBitsSet(KnownZero.getBitWidth(),
KnownZero.getBitWidth() - 1);
break;
case Intrinsic::xcore_testwct:
// Result is in the range 0 - 4.
KnownZero = APInt::getHighBitsSet(KnownZero.getBitWidth(),
KnownZero.getBitWidth() - 3);
break;
}
}
break;
}
}