import itertools
import random
import sys
+import uuid
def main():
+ element_types=['i8', 'i16', 'i32', 'i64', 'f32', 'f64']
parser = argparse.ArgumentParser(description=__doc__)
- parser.add_argument('seed',
- help='A string used to seed the RNG')
parser.add_argument('-v', '--verbose', action='store_true',
help='Show verbose output')
+ parser.add_argument('--seed', default=str(uuid.uuid4()),
+ help='A string used to seed the RNG')
parser.add_argument('--max-shuffle-height', type=int, default=16,
help='Specify a fixed height of shuffle tree to test')
parser.add_argument('--no-blends', dest='blends', action='store_false',
help='Include blends of two input vectors')
parser.add_argument('--fixed-bit-width', type=int, choices=[128, 256],
help='Specify a fixed bit width of vector to test')
+ parser.add_argument('--fixed-element-type', choices=element_types,
+ help='Specify a fixed element type to test')
parser.add_argument('--triple',
help='Specify a triple string to include in the IR')
args = parser.parse_args()
random.seed(args.seed)
+ if args.fixed_element_type is not None:
+ element_types=[args.fixed_element_type]
+
if args.fixed_bit_width is not None:
if args.fixed_bit_width == 128:
+ width_map={'i64': 2, 'i32': 4, 'i16': 8, 'i8': 16, 'f64': 2, 'f32': 4}
(width, element_type) = random.choice(
- [(2, 'i64'), (4, 'i32'), (8, 'i16'), (16, 'i8'),
- (2, 'f64'), (4, 'f32')])
+ [(width_map[t], t) for t in element_types])
elif args.fixed_bit_width == 256:
- (width, element_type) = random.choice([
- (4, 'i64'), (8, 'i32'), (16, 'i16'), (32, 'i8'),
- (4, 'f64'), (8, 'f32')])
+ width_map={'i64': 4, 'i32': 8, 'i16': 16, 'i8': 32, 'f64': 4, 'f32': 8}
+ (width, element_type) = random.choice(
+ [(width_map[t], t) for t in element_types])
else:
sys.exit(1) # Checked above by argument parsing.
else:
width = random.choice([2, 4, 8, 16, 32, 64])
- element_type = random.choice(['i8', 'i16', 'i32', 'i64', 'f32', 'f64'])
+ element_type = random.choice(element_types)
element_modulus = {
'i8': 1 << 8, 'i16': 1 << 16, 'i32': 1 << 32, 'i64': 1 << 64,
'f32': 1 << 32, 'f64': 1 << 64}[element_type]
shuffle_range = (2 * width) if args.blends else width
- shuffle_indices = [-1] + range(shuffle_range)
- shuffle_tree = [[[random.choice(shuffle_indices)
+ # Because undef (-1) saturates and is indistinguishable when testing the
+ # correctness of a shuffle, we want to bias our fuzz toward having a decent
+ # mixture of non-undef lanes in the end. With a deep shuffle tree, the
+ # probabilies aren't good so we need to bias things. The math here is that if
+ # we uniformly select between -1 and the other inputs, each element of the
+ # result will have the following probability of being undef:
+ #
+ # 1 - (shuffle_range/(shuffle_range+1))^max_shuffle_height
+ #
+ # More generally, for any probability P of selecting a defined element in
+ # a single shuffle, the end result is:
+ #
+ # 1 - P^max_shuffle_height
+ #
+ # The power of the shuffle height is the real problem, as we want:
+ #
+ # 1 - shuffle_range/(shuffle_range+1)
+ #
+ # So we bias the selection of undef at any given node based on the tree
+ # height. Below, let 'A' be 'len(shuffle_range)', 'C' be 'max_shuffle_height',
+ # and 'B' be the bias we use to compensate for
+ # C '((A+1)*A^(1/C))/(A*(A+1)^(1/C))':
+ #
+ # 1 - (B * A)/(A + 1)^C = 1 - A/(A + 1)
+ #
+ # So at each node we use:
+ #
+ # 1 - (B * A)/(A + 1)
+ # = 1 - ((A + 1) * A * A^(1/C))/(A * (A + 1) * (A + 1)^(1/C))
+ # = 1 - ((A + 1) * A^((C + 1)/C))/(A * (A + 1)^((C + 1)/C))
+ #
+ # This is the formula we use to select undef lanes in the shuffle.
+ A = float(shuffle_range)
+ C = float(args.max_shuffle_height)
+ undef_prob = 1.0 - (((A + 1.0) * pow(A, (C + 1.0)/C)) /
+ (A * pow(A + 1.0, (C + 1.0)/C)))
+
+ shuffle_tree = [[[-1 if random.random() <= undef_prob
+ else random.choice(range(shuffle_range))
for _ in itertools.repeat(None, width)]
for _ in itertools.repeat(None, args.max_shuffle_height - i)]
for i in xrange(args.max_shuffle_height)]
# Generate some string constants that we can use to report errors.
for i, r in enumerate(result):
if r != -1:
- s = ('FAIL(%(seed)s): lane %(lane)d, expected %(result)d, found %%d\\0A' %
+ s = ('FAIL(%(seed)s): lane %(lane)d, expected %(result)d, found %%d\n\\0A' %
{'seed': args.seed, 'lane': i, 'result': r})
s += ''.join(['\\00' for _ in itertools.repeat(None, 128 - len(s) + 2)])
print """
%%bad.%(i)d = trunc i2048 %%tmp.%(i)d to i32
call i32 (i8*, i8*, ...)* @sprintf(i8* %%str.ptr, i8* getelementptr inbounds ([128 x i8]* @error.%(i)d, i32 0, i32 0), i32 %%bad.%(i)d)
%%length.%(i)d = call i32 @strlen(i8* %%str.ptr)
- %%size.%(i)d = add i32 %%length.%(i)d, 1
- call i32 @write(i32 2, i8* %%str.ptr, i32 %%size.%(i)d)
+ call i32 @write(i32 2, i8* %%str.ptr, i32 %%length.%(i)d)
call void @llvm.trap()
unreachable
""" % dict(subst, i=i, next_i=i + 1, r=r)
projects / oota-llvm.git / blobdiff