From 4d13952d1427ad9a34dbc933898bca19a7feecec Mon Sep 17 00:00:00 2001
From: Frederik Hennig <frederik.hennig@fau.de>
Date: Wed, 17 Jan 2024 12:06:47 +0100
Subject: [PATCH] some cleanup. Notes on translation context.
---
src/pystencils/nbackend/arrays.py | 19 +--------
src/pystencils/nbackend/jit/__init__.py | 0
.../nbackend/translation/context.py | 41 +++++++++++++++++++
tests/nbackend/test_constant_folding.py | 4 ++
4 files changed, 47 insertions(+), 17 deletions(-)
create mode 100644 src/pystencils/nbackend/jit/__init__.py
create mode 100644 src/pystencils/nbackend/translation/context.py
diff --git a/src/pystencils/nbackend/arrays.py b/src/pystencils/nbackend/arrays.py
index 5cab54abc..fd416a20c 100644
--- a/src/pystencils/nbackend/arrays.py
+++ b/src/pystencils/nbackend/arrays.py
@@ -56,7 +56,7 @@ from .types import (
constify,
)
-from .typed_expressions import PsTypedVariable, PsTypedConstant, ExprOrConstant
+from .typed_expressions import PsTypedVariable, ExprOrConstant
class PsLinearizedArray:
@@ -67,27 +67,19 @@ class PsLinearizedArray:
name: str,
element_type: PsScalarType,
dim: int,
- offsets: tuple[int, ...] | None = None,
index_dtype: PsIntegerType = PsSignedIntegerType(64),
):
self._name = name
- if offsets is not None and len(offsets) != dim:
- raise ValueError(f"Must have exactly {dim} offsets.")
-
self._shape = tuple(
PsArrayShapeVar(self, d, constify(index_dtype)) for d in range(dim)
)
self._strides = tuple(
PsArrayStrideVar(self, d, constify(index_dtype)) for d in range(dim)
)
- self._element_type = element_type
-
- if offsets is None:
- offsets = (0,) * dim
+ self._element_type = element_type
self._dim = dim
- self._offsets = tuple(PsTypedConstant(o, index_dtype) for o in offsets)
self._index_dtype = index_dtype
@property
@@ -110,10 +102,6 @@ class PsLinearizedArray:
def element_type(self):
return self._element_type
- @property
- def offsets(self) -> tuple[PsTypedConstant, ...]:
- return self._offsets
-
def __eq__(self, other: object) -> bool:
if not isinstance(other, PsLinearizedArray):
return False
@@ -122,13 +110,11 @@ class PsLinearizedArray:
self._name,
self._element_type,
self._dim,
- self._offsets,
self._index_dtype,
) == (
other._name,
other._element_type,
other._dim,
- other._offsets,
other._index_dtype,
)
@@ -138,7 +124,6 @@ class PsLinearizedArray:
self._name,
self._element_type,
self._dim,
- self._offsets,
self._index_dtype,
)
)
diff --git a/src/pystencils/nbackend/jit/__init__.py b/src/pystencils/nbackend/jit/__init__.py
new file mode 100644
index 000000000..e69de29bb
diff --git a/src/pystencils/nbackend/translation/context.py b/src/pystencils/nbackend/translation/context.py
new file mode 100644
index 000000000..199315579
--- /dev/null
+++ b/src/pystencils/nbackend/translation/context.py
@@ -0,0 +1,41 @@
+
+class PsTranslationContext:
+ """The `PsTranslationContext` manages the translation process from the SymPy frontend
+ to the backend AST.
+
+ It does the following things:
+
+ - Default data types: The context knows the data types that should be applied by default
+ to SymPy expressions.
+ - Management of fields. The context manages all mappings from front-end `Field`s to their
+ underlying `PsLinearizedArray`s.
+ - Collection of constraints. All constraints that arise during translation are collected in the
+ context, and finally attached to the kernel function object once translation is complete.
+
+ Data Types
+ ----------
+
+ - The `index_dtype` is the data type used throughout translation for all loop counters and array indexing.
+ - The `default_numeric_dtype` is the data type assigned by default to all symbols occuring in SymPy assignments
+
+ Fields and Arrays
+ -----------------
+
+ There's several types of fields that need to be mapped to arrays.
+
+ - `FieldType.GENERIC` corresponds to domain fields.
+ Domain fields can only be accessed by relative offsets, and therefore must always
+ be associated with an *iteration domain* that provides a spatial index tuple.
+ All domain fields associated with the same domain must have the same spatial shape, modulo ghost layers.
+ A field and its array may be associated with multiple iteration domains.
+ - `FieldType.INDEXED` are 1D arrays of index structures. They must be accessed by a single running index.
+ If there is at least one indexed field present there must also exist an index source for that field
+ (loop or device indexing).
+ An indexed field may itself be an index source for domain fields.
+ - `FieldType.BUFFER` are 1D arrays whose indices must be incremented with each access.
+ Within a domain, a buffer may be either written to or read from, never both.
+
+
+
+
+ """
diff --git a/tests/nbackend/test_constant_folding.py b/tests/nbackend/test_constant_folding.py
index 12bc15b69..c297534b4 100644
--- a/tests/nbackend/test_constant_folding.py
+++ b/tests/nbackend/test_constant_folding.py
@@ -27,6 +27,7 @@ def test_constant_folding_int(width):
assert folder(expr) == PsTypedConstant(-53, SInt(width))
+@pytest.mark.xfail(reason="Current constant folder does not handle products")
@pytest.mark.parametrize("width", (8, 16, 32, 64))
def test_constant_folding_product(width):
"""
@@ -46,8 +47,11 @@ def test_constant_folding_product(width):
assert folder(expr) == PsTypedConstant(-24, SInt(width))
+@pytest.mark.xfail(reason="Current constant folder does not handle divisions")
@pytest.mark.parametrize("width", (32, 64))
def test_constant_folding_float(width):
+ """The pymbolic constant folder does not fold quotients. This test serves as a reminder
+ to consider that behaviour"""
folder = ConstantFoldingMapper()
expr = pb.Quotient(
--
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