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target-i386: compute eflags outside rcl/rcr helper

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Always compute EFLAGS first since it is needed whenever
the shift is non-zero, i.e. most of the time.  This makes it possible
to remove some writes of CC_OP_EFLAGS to cpu_cc_op and more importantly
removes cases where s->cc_op becomes CC_OP_DYNAMIC.  Also, we can
remove cc_tmp and just modify cc_src from within the helper.

Finally, always follow gen_compute_eflags(cpu_cc_src) by setting s->cc_op
and discarding cpu_cc_dst.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
This commit is contained in:
Paolo Bonzini 2012-10-06 00:18:55 +02:00 • committed by Richard Henderson
parent 0ff6addd92
commit f5847c912d
3 changed files with 8 additions and 25 deletions
Download patch file Download diff file Expand all files Collapse all files

12
target-i386/shift_helper_template.h
View file

@ -55,7 +55,7 @@ target_ulong glue(helper_rcl, SUFFIX)(CPUX86State *env, target_ulong t0,
count = rclb_table[count];
#endif
if (count) {
eflags = helper_cc_compute_all(env, CC_OP);
eflags = env->cc_src;
t0 &= DATA_MASK;
src = t0;
res = (t0 << count) | ((target_ulong)(eflags & CC_C) << (count - 1));
@ -63,11 +63,9 @@ target_ulong glue(helper_rcl, SUFFIX)(CPUX86State *env, target_ulong t0,
res |= t0 >> (DATA_BITS + 1 - count);
}
t0 = res;
env->cc_tmp = (eflags & ~(CC_C | CC_O)) |
env->cc_src = (eflags & ~(CC_C | CC_O)) |
(lshift(src ^ t0, 11 - (DATA_BITS - 1)) & CC_O) |
((src >> (DATA_BITS - count)) & CC_C);
} else {
env->cc_tmp = -1;
}
return t0;
}
@ -86,7 +84,7 @@ target_ulong glue(helper_rcr, SUFFIX)(CPUX86State *env, target_ulong t0,
count = rclb_table[count];
#endif
if (count) {
eflags = helper_cc_compute_all(env, CC_OP);
eflags = env->cc_src;
t0 &= DATA_MASK;
src = t0;
res = (t0 >> count) |
@ -95,11 +93,9 @@ target_ulong glue(helper_rcr, SUFFIX)(CPUX86State *env, target_ulong t0,
res |= t0 << (DATA_BITS + 1 - count);
}
t0 = res;
env->cc_tmp = (eflags & ~(CC_C | CC_O)) |
env->cc_src = (eflags & ~(CC_C | CC_O)) |
(lshift(src ^ t0, 11 - (DATA_BITS - 1)) & CC_O) |
((src >> (count - 1)) & CC_C);
} else {
env->cc_tmp = -1;
}
return t0;
}