X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=utils%2Fshuffle_fuzz.py;h=eac34422b3fb5f67609db02ebf9cf3326c16f7d9;hb=8d5b76e5d406829f7049dfb6cc6e772e137ed2f0;hp=b70530a0ed37ab0ba4e53a0b9b463cdb4efdb38a;hpb=ba20fb11a78f1132ad7047459e0d3c0bba4721ae;p=oota-llvm.git diff --git a/utils/shuffle_fuzz.py b/utils/shuffle_fuzz.py index b70530a0ed3..eac34422b3f 100755 --- a/utils/shuffle_fuzz.py +++ b/utils/shuffle_fuzz.py @@ -20,6 +20,7 @@ import sys import uuid def main(): + element_types=['i8', 'i16', 'i32', 'i64', 'f32', 'f64'] parser = argparse.ArgumentParser(description=__doc__) parser.add_argument('-v', '--verbose', action='store_true', help='Show verbose output') @@ -31,35 +32,77 @@ def main(): 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)] @@ -130,7 +173,7 @@ entry:""" % dict(subst, # 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 """ @@ -155,7 +198,7 @@ define i32 @main() { entry: ; Create a scratch space to print error messages. %%str = alloca [128 x i8] - %%str.ptr = getelementptr inbounds [128 x i8]* %%str, i32 0, i32 0 + %%str.ptr = getelementptr inbounds [128 x i8], [128 x i8]* %%str, i32 0, i32 0 ; Build the input vector and call the test function. %%v = call fastcc <%(N)d x %(T)s> @test_wrapper(%(inputs)s) @@ -190,10 +233,9 @@ die.%(i)d: ; Capture the actual value and print an error message. %%tmp.%(i)d = zext %(IT)s %%v.%(i)d to i2048 %%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) + call i32 (i8*, i8*, ...) @sprintf(i8* %%str.ptr, i8* getelementptr inbounds ([128 x i8], [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)