From e4fe5396cbe8d3fb8b18587f01edb37766d431fc Mon Sep 17 00:00:00 2001
From: Andreas Kloeckner <inform@tiker.net>
Date: Fri, 22 Jul 2011 10:09:10 -0500
Subject: [PATCH] Fix, better messages from conflict detector.
---
examples/matrix-ops.py | 9 +++------
loopy/__init__.py | 13 +++++++++----
2 files changed, 12 insertions(+), 10 deletions(-)
diff --git a/examples/matrix-ops.py b/examples/matrix-ops.py
index eb1ffb7bf..e1f81b878 100644
--- a/examples/matrix-ops.py
+++ b/examples/matrix-ops.py
@@ -136,12 +136,9 @@ def image_matrix_mul(ctx_factory=cl.create_some_context):
knl = lp.split_dimension(knl, "i", 16, outer_tag="g.0", inner_tag="l.1")
knl = lp.split_dimension(knl, "j", 16, outer_tag="g.1", inner_tag="l.0")
knl = lp.split_dimension(knl, "k", 32)
- # slow, but conflict-free
- #knl = lp.add_prefetch(knl, 'a', ["i_inner", "k_inner"])
- #knl = lp.add_prefetch(knl, 'b', ["j_inner", "k_inner"])
- # fast
- knl = lp.add_prefetch(knl, 'a', ["k_inner", "i_inner"])
- knl = lp.add_prefetch(knl, 'b', ["k_inner", "j_inner", ])
+ # conflict-free
+ knl = lp.add_prefetch(knl, 'a', ["i_inner", "k_inner"])
+ knl = lp.add_prefetch(knl, 'b', ["j_inner", "k_inner"])
assert knl.get_invalid_reason() is None
kernel_gen = (lp.insert_register_prefetches(knl)
diff --git a/loopy/__init__.py b/loopy/__init__.py
index 78ee835a2..07c2450a6 100644
--- a/loopy/__init__.py
+++ b/loopy/__init__.py
@@ -38,6 +38,9 @@ register_mpz_with_pymbolic()
# TODO: Custom reductions per red. axis
+# TODO Tim: implement efficient div_ceil?
+# TODO Tim: why are corner cases inefficient?
+
@@ -1873,6 +1876,7 @@ def preprocess_prefetch(kernel):
min_mult = cl_char.local_memory_bank_count(kernel.device)
good_incr = None
new_dsl = dim_storage_lengths
+ min_why_not = None
for increment in range(dim_storage_lengths[-1]//2):
@@ -1884,21 +1888,22 @@ def preprocess_prefetch(kernel):
# will choose smallest increment 'automatically'
if new_mult < min_mult:
- new_lmem_use = other_pf_sizes+pf.itemsize*product(new_dsl)
+ new_lmem_use = other_pf_sizes + pf.itemsize*product(new_dsl)
if new_lmem_use < lmem_size:
new_dsl = test_dsl
min_mult = new_mult
+ min_why_not = why_not
good_incr = increment
if min_mult != 1:
from warnings import warn
warn("could not find a conflict-free mem layout "
"for prefetch of '%s' "
- "(currently: %dx conflict, increment: %d)"
- % (pf.input_vector, min_mult, good_incr),
+ "(currently: %dx conflict, increment: %d, reason: %s)"
+ % (pf.input_vector, min_mult, good_incr, min_why_not),
LoopyAdvisory)
- new_pf = pf.copy(dim_storage_lengths=dim_storage_lengths,
+ new_pf = pf.copy(dim_storage_lengths=new_dsl,
name="prefetch_%s_%d" % (pf.input_vector, i_pf))
new_prefetch_dict[pf.input_vector, pf.index_expr] = new_pf
all_pf_list[i_pf] = new_pf
--
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