GNU Compiler Collection (GCC) Internals: Vectors |
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VEC_LSHIFT_EXPR
VEC_RSHIFT_EXPR
These nodes represent whole vector left and right shifts, respectively. The first operand is the vector to shift; it will always be of vector type. The second operand is an expression for the number of bits by which to shift. Note that the result is undefined if the second operand is larger than or equal to the first operand’s type size.
VEC_WIDEN_MULT_HI_EXPR
VEC_WIDEN_MULT_LO_EXPR
These nodes represent widening vector multiplication of the high and low
parts of the two input vectors, respectively. Their operands are vectors
that contain the same number of elements (N
) of the same integral type.
The result is a vector that contains half as many elements, of an integral type
whose size is twice as wide. In the case of VEC_WIDEN_MULT_HI_EXPR
the
high N/2
elements of the two vector are multiplied to produce the
vector of N/2
products. In the case of VEC_WIDEN_MULT_LO_EXPR
the
low N/2
elements of the two vector are multiplied to produce the
vector of N/2
products.
VEC_UNPACK_HI_EXPR
VEC_UNPACK_LO_EXPR
These nodes represent unpacking of the high and low parts of the input vector,
respectively. The single operand is a vector that contains N
elements
of the same integral or floating point type. The result is a vector
that contains half as many elements, of an integral or floating point type
whose size is twice as wide. In the case of VEC_UNPACK_HI_EXPR
the
high N/2
elements of the vector are extracted and widened (promoted).
In the case of VEC_UNPACK_LO_EXPR
the low N/2
elements of the
vector are extracted and widened (promoted).
VEC_UNPACK_FLOAT_HI_EXPR
VEC_UNPACK_FLOAT_LO_EXPR
These nodes represent unpacking of the high and low parts of the input vector,
where the values are converted from fixed point to floating point. The
single operand is a vector that contains N
elements of the same
integral type. The result is a vector that contains half as many elements
of a floating point type whose size is twice as wide. In the case of
VEC_UNPACK_HI_EXPR
the high N/2
elements of the vector are
extracted, converted and widened. In the case of VEC_UNPACK_LO_EXPR
the low N/2
elements of the vector are extracted, converted and widened.
VEC_PACK_TRUNC_EXPR
This node represents packing of truncated elements of the two input vectors into the output vector. Input operands are vectors that contain the same number of elements of the same integral or floating point type. The result is a vector that contains twice as many elements of an integral or floating point type whose size is half as wide. The elements of the two vectors are demoted and merged (concatenated) to form the output vector.
VEC_PACK_SAT_EXPR
This node represents packing of elements of the two input vectors into the output vector using saturation. Input operands are vectors that contain the same number of elements of the same integral type. The result is a vector that contains twice as many elements of an integral type whose size is half as wide. The elements of the two vectors are demoted and merged (concatenated) to form the output vector.
VEC_PACK_FIX_TRUNC_EXPR
This node represents packing of elements of the two input vectors into the output vector, where the values are converted from floating point to fixed point. Input operands are vectors that contain the same number of elements of a floating point type. The result is a vector that contains twice as many elements of an integral type whose size is half as wide. The elements of the two vectors are merged (concatenated) to form the output vector.
VEC_COND_EXPR
These nodes represent ?:
expressions. The three operands must be
vectors of the same size and number of elements. The second and third
operands must have the same type as the entire expression. The first
operand is of signed integral vector type. If an element of the first
operand evaluates to a zero value, the corresponding element of the
result is taken from the third operand. If it evaluates to a minus one
value, it is taken from the second operand. It should never evaluate to
any other value currently, but optimizations should not rely on that
property. In contrast with a COND_EXPR
, all operands are always
evaluated.
SAD_EXPR
This node represents the Sum of Absolute Differences operation. The three operands must be vectors of integral types. The first and second operand must have the same type. The size of the vector element of the third operand must be at lease twice of the size of the vector element of the first and second one. The SAD is calculated between the first and second operands, added to the third operand, and returned.
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