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| -rw-r--r-- | llvm/docs/LangRef.rst | 52 |
1 files changed, 49 insertions, 3 deletions
diff --git a/llvm/docs/LangRef.rst b/llvm/docs/LangRef.rst index 739267c8f58..dd822547cef 100644 --- a/llvm/docs/LangRef.rst +++ b/llvm/docs/LangRef.rst @@ -6790,6 +6790,55 @@ Semantics: The '``unreachable``' instruction has no defined semantics. +.. _unaryops: + +Unary Operations +----------------- + +Unary operators require a single operand, execute an operation on +it, and produce a single value. The operand might represent multiple +data, as is the case with the :ref:`vector <t_vector>` data type. The +result value has the same type as its operand. + +.. _i_fneg: + +'``fneg``' Instruction +^^^^^^^^^^^^^^^^^^^^^^ + +Syntax: +""""""" + +:: + + <result> = fneg [fast-math flags]* <ty> <op1> ; yields ty:result + +Overview: +""""""""" + +The '``fneg``' instruction returns the negation of its operand. + +Arguments: +"""""""""" + +The argument to the '``fneg``' instruction must be a +:ref:`floating-point <t_floating>` or :ref:`vector <t_vector>` of +floating-point values. + +Semantics: +"""""""""" + +The value produced is a copy of the operand with its sign bit flipped. +This instruction can also take any number of :ref:`fast-math +flags <fastmath>`, which are optimization hints to enable otherwise +unsafe floating-point optimizations: + +Example: +"""""""" + +.. code-block:: text + + <result> = fneg float %val ; yields float:result = -%var + .. _binaryops: Binary Operations @@ -6965,9 +7014,6 @@ Overview: The '``fsub``' instruction returns the difference of its two operands. -Note that the '``fsub``' instruction is used to represent the '``fneg``' -instruction present in most other intermediate representations. - Arguments: """""""""" |
