Author: Armin Rigo <[email protected]>
Branch: json-decoder-maps
Changeset: r97567:a6922067f4ef
Date: 2019-09-20 13:14 +0200
http://bitbucket.org/pypy/pypy/changeset/a6922067f4ef/
Log: Review, minor tweaks
diff --git a/pypy/module/_pypyjson/simd.py b/pypy/module/_pypyjson/simd.py
--- a/pypy/module/_pypyjson/simd.py
+++ b/pypy/module/_pypyjson/simd.py
@@ -68,9 +68,9 @@
word >>= 8
assert 0 # XXX ???
-def splice_words(word, offset, other):
- mask = ((~r_uint(0)) << (8 * offset))
- return (word & mask) | (other & ~mask)
+def set_high_bytes_to_zero(word, keep_bytes):
+ mask = ((~r_uint(0)) << (8 * keep_bytes))
+ return word & ~mask
@@ -107,11 +107,13 @@
# didn't find end of string yet, look at remaining chars
word = 0
shift = 0
- i = 0
- for i in range(num_safe_reads * WORD_SIZE + startpos, length + 1):
+ i = startpos + num_safe_reads * WORD_SIZE
+ while True: # this loop should run at most WORD_SIZE times,
+ # if we assume that ll_chars[length] == '\x00'
ch = ll_chars[i]
if ch == '"' or ch == '\\' or ch < '\x20':
break
+ i += 1
bits |= ord(ch)
word |= ord(ch) << shift
shift += 8
@@ -125,7 +127,7 @@
nonzero = index_nonzero(cond)
endposition = startpos + i * WORD_SIZE + nonzero
if nonzero:
- word = splice_words(r_uint(0), nonzero, word)
+ word = set_high_bytes_to_zero(word, nonzero)
bits |= word
strhash = intmask((1000003 * strhash) ^ intmask(word))
@@ -149,16 +151,14 @@
bits |= word
else:
# didn't find end of string yet, look at remaining chars
- word = 0
- shift = 0
- i = 0
- for i in range(num_safe_reads * WORD_SIZE + startpos, length + 1):
+ i = startpos + num_safe_reads * WORD_SIZE
+ while True: # this loop should run at most WORD_SIZE times,
+ # if we assume that ll_chars[length] == '\x00'
ch = ll_chars[i]
if ch == '"' or ch == '\\' or ch < '\x20':
break
+ i += 1
bits |= ord(ch)
- word |= ord(ch) << shift
- shift += WORD_SIZE
nonascii = bool(bits & char_repeated_word_width(chr(0x80)))
return nonascii, i
@@ -167,7 +167,7 @@
nonzero = index_nonzero(cond)
endposition = startpos + i * WORD_SIZE + nonzero
if nonzero:
- word = splice_words(r_uint(0), nonzero, word)
+ word = set_high_bytes_to_zero(word, nonzero)
bits |= word
nonascii = bool(bits & char_repeated_word_width(chr(0x80)))
@@ -204,15 +204,22 @@
strhash = intmask((1000003 * strhash) ^ word)
return strhash, bool(bits & 0x80), i
[email protected]_inline
+def find_end_of_string_slow_no_hash(ll_chars, i, length):
+ bits = 0
+ while True:
+ # this loop is a fast path for strings which do not contain escape
+ # characters
+ ch = ll_chars[i]
+ if ch == '"' or ch == '\\' or ch < '\x20':
+ break
+ i += 1
+ bits |= ord(ch)
+ return bool(bits & 0x80), i
+
if USE_SIMD:
find_end_of_string = find_end_of_string_simd_unaligned
find_end_of_string_no_hash = find_end_of_string_simd_unaligned_no_hash
else:
find_end_of_string = find_end_of_string_slow
-
- @objectmodel.always_inline
- def find_end_of_string_no_hash(ll_chars, i, length):
- _, nonascii, i = find_end_of_string_slow(ll_chars, i, length)
- return (nonascii, i)
-
-
+ find_end_of_string_no_hash = find_end_of_string_slow_no_hash
diff --git a/pypy/module/_pypyjson/test/test_simd.py
b/pypy/module/_pypyjson/test/test_simd.py
--- a/pypy/module/_pypyjson/test/test_simd.py
+++ b/pypy/module/_pypyjson/test/test_simd.py
@@ -5,6 +5,7 @@
from pypy.module._pypyjson.simd import USE_SIMD
from pypy.module._pypyjson.simd import find_end_of_string_slow
+from pypy.module._pypyjson.simd import find_end_of_string_slow_no_hash
from pypy.module._pypyjson.simd import print_chars
from pypy.module._pypyjson.simd import find_end_of_string_simd_unaligned,
WORD_SIZE
from pypy.module._pypyjson.simd import
find_end_of_string_simd_unaligned_no_hash
@@ -74,6 +75,8 @@
(string, startindex) = a
res = ll(find_end_of_string_slow, string, startindex, len(string))
hash, nonascii1, endposition1 = res
+ res2 = ll(find_end_of_string_slow_no_hash, string, startindex, len(string))
+ assert res2 == (nonascii1, endposition1)
ch = string[endposition1]
assert ch == '"' or ch == '\\' or ch < '\x20'
for ch in string[startindex:endposition1]:
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