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| author | Richard Henderson <richard.henderson@linaro.org> | 2023-01-09 12:18:56 -0800 |
|---|---|---|
| committer | Thomas Huth <thuth@redhat.com> | 2023-02-27 09:15:39 +0100 |
| commit | e73a0f4075a78de9a62beeddb41c54a4090e0777 (patch) | |
| tree | b2cf451f3899fe016476356201dc848e4de58182 /target/s390x | |
| parent | 61dee10ff00720e6e056824b4548c914632ef6fe (diff) | |
| download | qemu-e73a0f4075a78de9a62beeddb41c54a4090e0777.zip qemu-e73a0f4075a78de9a62beeddb41c54a4090e0777.tar.gz qemu-e73a0f4075a78de9a62beeddb41c54a4090e0777.tar.bz2 | |
target/s390x: Hoist some computation in access_memmove
Ensure that the total length is in a local variable
across the byte loop. Compute size1 difference once.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Message-Id: <20230109201856.3916639-8-richard.henderson@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Diffstat (limited to 'target/s390x')
| -rw-r--r-- | target/s390x/tcg/mem_helper.c | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/target/s390x/tcg/mem_helper.c b/target/s390x/tcg/mem_helper.c index f28126f..e51a0db 100644 --- a/target/s390x/tcg/mem_helper.c +++ b/target/s390x/tcg/mem_helper.c @@ -299,16 +299,17 @@ static void access_set_byte(CPUS390XState *env, S390Access *access, static void access_memmove(CPUS390XState *env, S390Access *desta, S390Access *srca, uintptr_t ra) { + int len = desta->size1 + desta->size2; int diff; - g_assert(desta->size1 + desta->size2 == srca->size1 + srca->size2); + assert(len == srca->size1 + srca->size2); /* Fallback to slow access in case we don't have access to all host pages */ if (unlikely(!desta->haddr1 || (desta->size2 && !desta->haddr2) || !srca->haddr1 || (srca->size2 && !srca->haddr2))) { int i; - for (i = 0; i < desta->size1 + desta->size2; i++) { + for (i = 0; i < len; i++) { uint8_t byte = access_get_byte(env, srca, i, ra); access_set_byte(env, desta, i, byte, ra); @@ -316,20 +317,20 @@ static void access_memmove(CPUS390XState *env, S390Access *desta, return; } - if (srca->size1 == desta->size1) { + diff = desta->size1 - srca->size1; + if (likely(diff == 0)) { memmove(desta->haddr1, srca->haddr1, srca->size1); if (unlikely(srca->size2)) { memmove(desta->haddr2, srca->haddr2, srca->size2); } - } else if (srca->size1 < desta->size1) { - diff = desta->size1 - srca->size1; + } else if (diff > 0) { memmove(desta->haddr1, srca->haddr1, srca->size1); memmove(desta->haddr1 + srca->size1, srca->haddr2, diff); if (likely(desta->size2)) { memmove(desta->haddr2, srca->haddr2 + diff, desta->size2); } } else { - diff = srca->size1 - desta->size1; + diff = -diff; memmove(desta->haddr1, srca->haddr1, desta->size1); memmove(desta->haddr2, srca->haddr1 + desta->size1, diff); if (likely(srca->size2)) { |