When generating a floating point comparison we currently unconditionally
generate VCMPE. This has the sideeffect of setting the cumulative Invalid
bit in FPSCR if any of the operands are QNaN.
It is expected that use of a relational predicate on a QNaN value should
raise Invalid. Quoting from the C standard:
The relational and equality operators support the usual mathematical
relationships between numeric values. For any ordered pair of numeric
values exactly one of relationships the less, greater, equal and is true.
Relational operators may raise the floating-point exception when argument
values are NaNs.
The standard doesn't explicitly state the expectation for equality operators,
but the implication and obvious expectation is that equality operators
should not raise Invalid on a QNaN input, as those predicates are wholly
defined on unordered inputs (to return not equal).
Therefore, add a new operand to ARMISD::FPCMP and FPCMPZ indicating if
QNaN should raise Invalid, and pipe that through to TableGen.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@294945 91177308-0d34-0410-b5e6-96231b3b80d8
Given vsel_cc, op1, op2, since vsel has no LE/LT, to generate vsel for
such selection, it needs to inverse cc and swap op1 and op2. To inverse
cc, both L/G and E bits should be flipped.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@197615 91177308-0d34-0410-b5e6-96231b3b80d8
This uses the ARMcmov pattern that Tim cleaned up in r188995.
Thanks to Simon Tatham for his floating point help!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189024 91177308-0d34-0410-b5e6-96231b3b80d8
James Molloy