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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>
This commit is contained in:
Richard Henderson 2023-01-09 12:18:56 -08:00 committed by Thomas Huth
parent 61dee10ff0
commit e73a0f4075
1 changed files with 7 additions and 6 deletions
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13
target/s390x/tcg/mem_helper.c
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@ -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)) {