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authorLei Zhang <thestig@chromium.org>2018-05-16 18:21:56 +0000
committerChromium commit bot <commit-bot@chromium.org>2018-05-16 18:21:56 +0000
commitc8f4e72cc26bd749bba8ad0d44d2c2bf838714b0 (patch)
tree4df470c7d303b965757f48d9b851e3c6bb38e244 /core/fxcodec
parent2be77a455df631ecbb5fbcc3f763bc606d7236f3 (diff)
downloadpdfium-c8f4e72cc26bd749bba8ad0d44d2c2bf838714b0.tar.xz
Avoid a memset() in FindBit() in the fax codec.
FindBit() is called frequently by other fax codec code. Use 16 more bytes of space to store the two possible values memset() can set. Change-Id: Ibeb549c44928bbb468ac4eb4cef2d9339cf6490d Reviewed-on: https://pdfium-review.googlesource.com/32630 Reviewed-by: Henrique Nakashima <hnakashima@chromium.org> Commit-Queue: Lei Zhang <thestig@chromium.org>
Diffstat (limited to 'core/fxcodec')
-rw-r--r--core/fxcodec/codec/fx_codec_fax.cpp7
1 files changed, 5 insertions, 2 deletions
diff --git a/core/fxcodec/codec/fx_codec_fax.cpp b/core/fxcodec/codec/fx_codec_fax.cpp
index 8c4b215a1b..09d0ebc157 100644
--- a/core/fxcodec/codec/fx_codec_fax.cpp
+++ b/core/fxcodec/codec/fx_codec_fax.cpp
@@ -73,8 +73,11 @@ int FindBit(const uint8_t* data_buf, int max_pos, int start_pos, bool bit) {
// Try reading in bigger chunks in case there are long runs to be skipped.
static constexpr int kBulkReadSize = 8;
if (max_byte >= kBulkReadSize && byte_pos < max_byte - kBulkReadSize) {
- uint8_t skip_block[kBulkReadSize];
- memset(skip_block, skip, kBulkReadSize);
+ static constexpr uint8_t skip_block_0[kBulkReadSize] = {
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
+ static constexpr uint8_t skip_block_1[kBulkReadSize] = {
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
+ const uint8_t* skip_block = bit ? skip_block_0 : skip_block_1;
while (byte_pos < max_byte - kBulkReadSize &&
memcmp(data_buf + byte_pos, skip_block, kBulkReadSize) == 0) {
byte_pos += kBulkReadSize;