Literal Array Class

An AbstractArray where all elements have the same constant value. This arises from a literal in traced code (x + 1, say). A nv_fill() is a recorded operation rather than a constant, so its output is an ordinary AbstractArray.

Usage

LiteralArray(data, shape, dtype = default_dtype(data))

Arguments

data

(double(1) | integer(1) | logical(1) | AnvlArray)
The scalar value, or a one-element AnvlArray – for which dtype has to be named, since the default takes it from an R value's storage type.

shape

(stablehlo::Shape | integer())
The shape of the array.

dtype

(tengen::DataType)
The data type. For the default, see default_dtypes()).

Lowering

LiteralArrays become constants inlined into the StableHLO program. I.e., they lower to hlo_tensor().

Examples

x <- LiteralArray(1L, shape = integer())
x
#> LiteralArray(1, i32, ()) 
shape(x)
#> integer(0)
naxes(x)
#> [1] 0
dtype(x)
#> <i32>
# how it appears during tracing: an R literal that meets nothing
graph <- trace_fn(function() 1, list())
graph
#> <AnvlGraph> () {
#>   return 1:f32
#> }
graph$outputs[[1]]$aval
#> LiteralArray(1, f32, ()) 
# a `nv_fill()`, by contrast, is a recorded operation
graph <- trace_fn(function() nv_fill(2L, shape = c(2, 2)), list())
graph
#> <AnvlGraph> () {
#>   %1: i32[2,2] = fill [value = 2, dtype = i32, shape = c(2, 2)] ()
#>   return %1
#> }
graph$outputs[[1]]$aval
#> AbstractArray(dtype=i32, shape=2x2)