RealCopySign¶
A real with the magnitude of one operand and the sign of another.
Declaration¶
Syntax¶
RealCopySign(expr target, expr source, ttype type, expr? value)
Arguments¶
Argument |
Description |
|---|---|
|
the value whose magnitude is taken. |
|
the value whose sign is taken. |
|
the type of the expression. |
|
the compile time value of the expression, when the frontend could fold it; |
Return values¶
The value of the expression.
Description¶
This is sign(a, b). It is a node of its own rather than an intrinsic call
because it maps to a single machine instruction, and because it is generated
by the sign_from_value optimisation pass.
The sign is copied from the bit, so a negative zero source gives a negative result.
Examples¶
(RealCopySign
:target (Var
:v (SymbolRef 1 "x")
)
:source (RealConstant
:r -1.0
:type (Real
:kind 8
)
)
:type (Real
:kind 8
)
:value nil
)
It comes from this complete ASR text document:
(TranslationUnit
:symtab (SymbolTable
:id 0
:symbols {
"main" (Program
:symtab (SymbolTable
:id 1
:symbols {
"b" (Variable
:parent_symtab 1
:name "b"
:dependencies []
:intent :Local
:symbolic_value nil
:value nil
:storage :Default
:type (Logical
:kind 4
)
:type_declaration nil
:abi :Source
:access :Public
:presence :Required
:value_attr false
:target_attr false
:contiguous_attr false
:bindc_name nil
:is_volatile false
:is_protected false
:pass_attr :NotMethod
:self_argument nil
:codims []
)
"x" (Variable
:parent_symtab 1
:name "x"
:dependencies []
:intent :Local
:symbolic_value nil
:value nil
:storage :Default
:type (Real
:kind 8
)
:type_declaration nil
:abi :Source
:access :Public
:presence :Required
:value_attr false
:target_attr false
:contiguous_attr false
:bindc_name nil
:is_volatile false
:is_protected false
:pass_attr :NotMethod
:self_argument nil
:codims []
)
"y" (Variable
:parent_symtab 1
:name "y"
:dependencies []
:intent :Local
:symbolic_value nil
:value nil
:storage :Default
:type (Real
:kind 8
)
:type_declaration nil
:abi :Source
:access :Public
:presence :Required
:value_attr false
:target_attr false
:contiguous_attr false
:bindc_name nil
:is_volatile false
:is_protected false
:pass_attr :NotMethod
:self_argument nil
:codims []
)
}
)
:name "main"
:dependencies []
:body [
(Assignment
:target (Var
:v (SymbolRef 1 "x")
)
:value (RealConstant
:r 2.5
:type (Real
:kind 8
)
)
:overloaded nil
:realloc_lhs false
:move_allocation false
)
(Assignment
:target (Var
:v (SymbolRef 1 "y")
)
:value (RealBinOp
:left (Var
:v (SymbolRef 1 "x")
)
:op :Div
:right (RealConstant
:r 2.0
:type (Real
:kind 8
)
)
:type (Real
:kind 8
)
:value nil
)
:overloaded nil
:realloc_lhs false
:move_allocation false
)
(Assignment
:target (Var
:v (SymbolRef 1 "y")
)
:value (RealUnaryMinus
:arg (Var
:v (SymbolRef 1 "x")
)
:type (Real
:kind 8
)
:value nil
)
:overloaded nil
:realloc_lhs false
:move_allocation false
)
(Assignment
:target (Var
:v (SymbolRef 1 "y")
)
:value (RealSqrt
:arg (Var
:v (SymbolRef 1 "x")
)
:type (Real
:kind 8
)
:value nil
)
:overloaded nil
:realloc_lhs false
:move_allocation false
)
(Assignment
:target (Var
:v (SymbolRef 1 "y")
)
:value (RealCopySign
:target (Var
:v (SymbolRef 1 "x")
)
:source (RealConstant
:r -1.0
:type (Real
:kind 8
)
)
:type (Real
:kind 8
)
:value nil
)
:overloaded nil
:realloc_lhs false
:move_allocation false
)
(Assignment
:target (Var
:v (SymbolRef 1 "b")
)
:value (RealCompare
:left (Var
:v (SymbolRef 1 "x")
)
:op :GtE
:right (Var
:v (SymbolRef 1 "y")
)
:type (Logical
:kind 4
)
:value nil
)
:overloaded nil
:realloc_lhs false
:move_allocation false
)
]
)
}
)
:items []
)