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crypto: mips/crc32 - Clean up useless assignment operations

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When entering the "len & sizeof(u32)" branch, len must be less than 8.
So after one operation, len must be less than 4.
At this time, "len -= sizeof(u32)" is not necessary for 64-bit CPUs.

After that, replace `while' loops with equivalent `for' to make the
code structure a little bit better by the way.

Suggested-by: Maciej W. Rozycki <macro@orcam.me.uk>
Link: https://lore.kernel.org/all/alpine.DEB.2.21.2406281713040.43454@angie.orcam.me.uk/
Suggested-by: Herbert Xu <herbert@gondor.apana.org.au>
Link: https://lore.kernel.org/all/ZtqZpzMH_qMQqzyc@gondor.apana.org.au/
Signed-off-by: Guan Wentao <guanwentao@uniontech.com>
Signed-off-by: WangYuli <wangyuli@uniontech.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
WangYuli 2024-09-06 14:40:02 +08:00 committed by Herbert Xu
parent f29ca8f762
commit ca459e5f82
1 changed files with 34 additions and 30 deletions
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64
arch/mips/crypto/crc32-mips.c
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@ -77,24 +77,26 @@ static u32 crc32_mips_le_hw(u32 crc_, const u8 *p, unsigned int len)
{
u32 crc = crc_;
#ifdef CONFIG_64BIT
while (len >= sizeof(u64)) {
u64 value = get_unaligned_le64(p);
if (IS_ENABLED(CONFIG_64BIT)) {
for (; len >= sizeof(u64); p += sizeof(u64), len -= sizeof(u64)) {
u64 value = get_unaligned_le64(p);
CRC32(crc, value, d);
p += sizeof(u64);
len -= sizeof(u64);
}
CRC32(crc, value, d);
}
if (len & sizeof(u32)) {
#else /* !CONFIG_64BIT */
while (len >= sizeof(u32)) {
#endif
u32 value = get_unaligned_le32(p);
if (len & sizeof(u32)) {
u32 value = get_unaligned_le32(p);
CRC32(crc, value, w);
p += sizeof(u32);
len -= sizeof(u32);
CRC32(crc, value, w);
p += sizeof(u32);
}
} else {
for (; len >= sizeof(u32); len -= sizeof(u32)) {
u32 value = get_unaligned_le32(p);
CRC32(crc, value, w);
p += sizeof(u32);
}
}
if (len & sizeof(u16)) {
@ -117,24 +119,26 @@ static u32 crc32c_mips_le_hw(u32 crc_, const u8 *p, unsigned int len)
{
u32 crc = crc_;
#ifdef CONFIG_64BIT
while (len >= sizeof(u64)) {
u64 value = get_unaligned_le64(p);
if (IS_ENABLED(CONFIG_64BIT)) {
for (; len >= sizeof(u64); p += sizeof(u64), len -= sizeof(u64)) {
u64 value = get_unaligned_le64(p);
CRC32C(crc, value, d);
p += sizeof(u64);
len -= sizeof(u64);
}
CRC32(crc, value, d);
}
if (len & sizeof(u32)) {
#else /* !CONFIG_64BIT */
while (len >= sizeof(u32)) {
#endif
u32 value = get_unaligned_le32(p);
if (len & sizeof(u32)) {
u32 value = get_unaligned_le32(p);
CRC32C(crc, value, w);
p += sizeof(u32);
len -= sizeof(u32);
CRC32(crc, value, w);
p += sizeof(u32);
}
} else {
for (; len >= sizeof(u32); len -= sizeof(u32)) {
u32 value = get_unaligned_le32(p);
CRC32(crc, value, w);
p += sizeof(u32);
}
}
if (len & sizeof(u16)) {