Opt-in gpu (#676)

* lock opencl and cuda tensor type declarations behind `defined` blocks

* only include when using

* `Tensor` is never `CudaTensor`

* remove irrellevant comment

Author: lilkeet

src/arraymancer/tensor/data_structure.nim

@@ -16,73 +16,87 @@ import
   ../laser/dynamic_stack_arrays,
   ../laser/tensor/datatypes,
   nimblas,
-  nimcuda/cuda12_5/[cuda_runtime_api, check],
   # Standard library
   std/[complex]
 
 export nimblas.OrderType, complex
 export datatypes, dynamic_stack_arrays
 
-type
-  CudaTensorRefTrackerObj*[T: SomeFloat] = object
-    value*: ptr UncheckedArray[T]
-
-  CudaTensorRefTracker*[T] = ref CudaTensorRefTrackerObj[T]
-
-  CudaStorage*[T: SomeFloat] = object
-    ## Opaque seq-like structure for storage on the Cuda backend.
-    ##
-    ## Nim garbage collector will automatically ask cuda to clear GPU memory if data becomes unused.
-    ##
-    # TODO: Forward declaring this and making this completely private prevent assignment in newCudaStorage from working
-    Flen*: int
-    Fdata*: ptr UncheckedArray[T]
-    Fref_tracking*: CudaTensorRefTracker[T] # We keep ref tracking for the GC in a separate field to avoid double indirection.
-
-  CudaTensor*[T: SomeFloat] = object
-    ## Tensor data structure stored on Nvidia GPU (Cuda)
-    ##   - ``shape``: Dimensions of the CudaTensor
-    ##   - ``strides``: Numbers of items to skip to get the next item along a dimension.
-    ##   - ``offset``: Offset to get the first item of the CudaTensor. Note: offset can be negative, in particular for slices.
-    ##   - ``storage``: An opaque data storage for the CudaTensor
-    ##
-    ## Warning ⚠:
-    ##   Assignment ``var a = b`` does not copy the data. Data modification on one CudaTensor will be reflected on the other.
-    ##   However modification on metadata (shape, strides or offset) will not affect the other tensor.
-    ##   Explicit copies can be made with ``clone``: ``var a = b.clone``
-    shape*: Metadata
-    strides*: Metadata
-    offset*: int
-    storage*: CudaStorage[T]
-
-  ClStorage*[T: SomeFloat] = object
-    ## Opaque seq-like structure for storage on the OpenCL backend.
-    Flen*: int
-    Fdata*: ptr UncheckedArray[T]
-    Fref_tracking*: ref[ptr UncheckedArray[T]] # We keep ref tracking for the GC in a separate field to avoid double indirection.
-
-  ClTensor*[T: SomeFloat] = object
-    ## Tensor data structure stored on OpenCL (CPU, GPU, FPGAs or other accelerators)
-    ##   - ``shape``: Dimensions of the CudaTensor
-    ##   - ``strides``: Numbers of items to skip to get the next item along a dimension.
-    ##   - ``offset``: Offset to get the first item of the CudaTensor. Note: offset can be negative, in particular for slices.
-    ##   - ``storage``: An opaque data storage for the CudaTensor
-    ##
-    ## Warning ⚠:
-    ##   Assignment ``var a = b`` does not copy the data. Data modification on one CudaTensor will be reflected on the other.
-    ##   However modification on metadata (shape, strides or offset) will not affect the other tensor.
-    ##   Explicit copies can be made with ``clone``: ``var a = b.clone``
-    shape*: Metadata
-    strides*: Metadata
-    offset*: int
-    storage*: ClStorage[T]
-
-  AnyTensor*[T] = Tensor[T] or CudaTensor[T] or ClTensor[T]
-
-
-proc deallocCuda*[T](p: CudaTensorRefTracker[T]) {.noSideEffect.}=
-  if not p.value.isNil:
-    check cudaFree(p.value)
+when defined(cuda):
+  import nimcuda/cuda12_5/[cuda_runtime_api, check]
+
+  type
+    CudaTensorRefTrackerObj*[T: SomeFloat] = object
+      value*: ptr UncheckedArray[T]
+
+    CudaTensorRefTracker*[T] = ref CudaTensorRefTrackerObj[T]
+
+    CudaStorage*[T: SomeFloat] = object
+      ## Opaque seq-like structure for storage on the Cuda backend.
+      ##
+      ## Nim garbage collector will automatically ask cuda to clear GPU memory if data becomes unused.
+      ##
+      # TODO: Forward declaring this and making this completely private prevent assignment in newCudaStorage from working
+      Flen*: int
+      Fdata*: ptr UncheckedArray[T]
+      Fref_tracking*: CudaTensorRefTracker[T] # We keep ref tracking for the GC in a separate field to avoid double indirection.
+
+    CudaTensor*[T: SomeFloat] = object
+      ## Tensor data structure stored on Nvidia GPU (Cuda)
+      ##   - ``shape``: Dimensions of the CudaTensor
+      ##   - ``strides``: Numbers of items to skip to get the next item along a dimension.
+      ##   - ``offset``: Offset to get the first item of the CudaTensor. Note: offset can be negative, in particular for slices.
+      ##   - ``storage``: An opaque data storage for the CudaTensor
+      ##
+      ## Warning ⚠:
+      ##   Assignment ``var a = b`` does not copy the data. Data modification on one CudaTensor will be reflected on the other.
+      ##   However modification on metadata (shape, strides or offset) will not affect the other tensor.
+      ##   Explicit copies can be made with ``clone``: ``var a = b.clone``
+      shape*: Metadata
+      strides*: Metadata
+      offset*: int
+      storage*: CudaStorage[T]
+
+  proc deallocCuda*[T](p: CudaTensorRefTracker[T]) {.noSideEffect.}=
+    if not p.value.isNil:
+      check cudaFree(p.value)
+
+when defined(opencl):
+  type
+    ClStorage*[T: SomeFloat] = object
+      ## Opaque seq-like structure for storage on the OpenCL backend.
+      Flen*: int
+      Fdata*: ptr UncheckedArray[T]
+      Fref_tracking*: ref[ptr UncheckedArray[T]] # We keep ref tracking for the GC in a separate field to avoid double indirection.
+
+    ClTensor*[T: SomeFloat] = object
+      ## Tensor data structure stored on OpenCL (CPU, GPU, FPGAs or other accelerators)
+      ##   - ``shape``: Dimensions of the CudaTensor
+      ##   - ``strides``: Numbers of items to skip to get the next item along a dimension.
+      ##   - ``offset``: Offset to get the first item of the CudaTensor. Note: offset can be negative, in particular for slices.
+      ##   - ``storage``: An opaque data storage for the CudaTensor
+      ##
+      ## Warning ⚠:
+      ##   Assignment ``var a = b`` does not copy the data. Data modification on one CudaTensor will be reflected on the other.
+      ##   However modification on metadata (shape, strides or offset) will not affect the other tensor.
+      ##   Explicit copies can be made with ``clone``: ``var a = b.clone``
+      shape*: Metadata
+      strides*: Metadata
+      offset*: int
+      storage*: ClStorage[T]
+
+when defined(cuda) and defined(opencl):
+  type AnyTensor*[T] = Tensor[T] or CudaTensor[T] or ClTensor[T]
+elif defined(cuda):
+  type AnyTensor*[T] = Tensor[T] or CudaTensor[T]
+elif defined(opencl):
+  type AnyTensor*[T] = Tensor[T] or ClTensor[T]
+else:
+  type AnyTensor*[T] = Tensor[T]
+
+type GpuTensor[T] = AnyTensor[T] and not Tensor[T]
+
+
 
 
 # ###############
@@ -102,10 +116,10 @@ proc `data=`*[T](t: var Tensor[T], s: seq[T]) {.deprecated: "Use copyFromRaw ins
 # Tensor Metadata
 # ################
 
-func rank*[T](t: CudaTensor[T] or ClTensor[T]): range[0 .. LASER_MAXRANK] {.inline.} =
+func rank*[T](t: GpuTensor[T]): range[0 .. LASER_MAXRANK] {.inline.} =
   t.shape.len
 
-func size*[T](t: CudaTensor[T] or ClTensor[T]): Natural {.inline.} =
+func size*[T](t: GpuTensor[T]): Natural {.inline.} =
   t.shape.product
 
 proc shape_to_strides*(shape: Metadata, layout: OrderType = rowMajor, result: var Metadata) {.noSideEffect.} =
@@ -131,7 +145,7 @@ proc shape_to_strides*(shape: Metadata, layout: OrderType = rowMajor, result: va
     accum *= shape[i]
   return
 
-func is_C_contiguous*(t: CudaTensor or ClTensor): bool =
+func is_C_contiguous*(t: GpuTensor): bool =
   ## Check if the tensor follows C convention / is row major
   var cur_size = 1
   for i in countdown(t.rank - 1,0):
@@ -182,14 +196,14 @@ proc get_offset_ptr*[T: KnownSupportsCopyMem](t: Tensor[T]): ptr T {.noSideEffec
 proc get_offset_ptr*[T: not KnownSupportsCopyMem](t: AnyTensor[T]): ptr T {.error: "`get_offset_ptr`" &
   " cannot be safely used for GC'ed types!".}
 
-proc get_data_ptr*[T](t: CudaTensor[T] or ClTensor[T]): ptr T {.noSideEffect, inline.}=
+proc get_data_ptr*[T](t: GpuTensor[T]): ptr T {.noSideEffect, inline.}=
   ## Input:
   ##     - A tensor
   ## Returns:
   ##     - A pointer to the real start of its data (no offset)
   cast[ptr T](t.storage.Fdata)
 
-proc get_offset_ptr*[T](t: CudaTensor[T] or ClTensor[T]): ptr T {.noSideEffect, inline.}=
+proc get_offset_ptr*[T](t: GpuTensor[T]): ptr T {.noSideEffect, inline.}=
   ## Input:
   ##     - A tensor
   ## Returns:

src/arraymancer/tensor/exporting.nim

@@ -33,17 +33,12 @@ proc toRawSeq*[T](t:Tensor[T]): seq[T] {.noSideEffect, deprecated: "This proc ca
   ## or that you raise your use-case in the issue tracker https://github.com/mratsim/Arraymancer/issues
   ## so that more suitable primitives can be crafted
 
-  # Due to forward declaration this proc must be declared
-  # after "cpu" proc are declared in init_cuda
-  when t is Tensor:
-    result = newSeq[T](t.size)
-    for i in 0 ..< t.size:
-      when T is KnownSupportsCopyMem:
-        result[i] = t.unsafe_raw_offset()[i]
-      else:
-        result[i] = t.storage.raw_buffer[i]
-  elif t is CudaTensor:
-    return t.cpu.data
+  result = newSeq[T](t.size)
+  for i in 0 ..< t.size:
+    when T is KnownSupportsCopyMem:
+      result[i] = t.unsafe_raw_offset()[i]
+    else:
+      result[i] = t.storage.raw_buffer[i]
 
 proc toFlatSeq*[T](t: Tensor[T]) : seq[T] =
   ## Export the data of the Tensor flattened as a Seq

src/arraymancer/tensor/private/p_checks.nim

@@ -19,7 +19,10 @@ import  ../../laser/private/nested_containers,
 when (NimMajor, NimMinor) < (1, 4):
   import ../../std_version_types
 
-include ./p_checks_cuda, ./p_checks_opencl
+when defined(cuda):
+  include ./p_checks_cuda
+when defined(opencl):
+  include ./p_checks_opencl
 
 func check_nested_elements*(shape: Metadata, len: int) {.inline.}=
   ## Compare the detected shape from flatten with the real length of the data