test-i386: QEMU_PACKED is not defined here

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
test-i386: make it compile with a recent gcc

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
target-i386: use OT_* consistently

Reviewed-by: Blue Swirl <blauwirbel@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
target-i386: introduce gen_ext_tl

Introduce a function that abstracts extracting an 8, 16, 32 or 64-bit value
with or without sign, generalizing gen_extu and gen_exts.

Reviewed-by: Blue Swirl <blauwirbel@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
target-i386: factor setting of s->cc_op handling for string functions

Set it to the appropriate CC_OP_SUBx constant in gen_scas/gen_cmps.
In the repz case it can be overridden to CC_OP_DYNAMIC after generating
the code.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
target-i386: drop cc_op argument of gen_jcc1

As in the gen_repz_scas/gen_repz_cmps case, delay setting
CC_OP_DYNAMIC in gen_jcc until after code generation.  All of
gen_jcc1/is_fast_jcc/gen_setcc_slow_T0 now work on s->cc_op, which makes
things a bit easier to follow and to patch.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
target-i386: move carry computation for inc/dec closer to gen_op_set_cc_op

This ensures the invariant that cpu_cc_op matches s->cc_op when calling
the helpers.  The next patches need this because gen_compute_eflags and
gen_compute_eflags_c will take care of setting cpu_cc_op.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
target-i386: move eflags computation closer to gen_op_set_cc_op

This ensures the invariant that cpu_cc_op matches s->cc_op when calling
the helpers.  The next patches need this because gen_compute_eflags and
gen_compute_eflags_c will take care of setting cpu_cc_op.

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.  These are slow and we want to
avoid them: CC_OP_EFLAGS is quite efficient once we paid the initial
cost of computing the flags.

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>
target-i386: compute eflags outside rcl/rcr helper

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>
target-i386: clean up sahf

Discard CC_DST and set s->cc_op immediately after computing EFLAGS.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
target-i386: use gen_jcc1 to compile loopz

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
target-i386: factor gen_op_set_cc_op/tcg_gen_discard_tl around computing flags

Before computing flags we need to store the cc_op to memory.  Move this
to gen_compute_eflags_c and gen_compute_eflags rather than doing it all
over the place.

Alo, after computing the flags in cpu_cc_src we are in EFLAGS mode.
Set s->cc_op and discard cpu_cc_dst in gen_compute_eflags, rather than
doing it all over the place.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
target-i386: Name the cc_op enumeration

Signed-off-by: Richard Henderson <rth@twiddle.net>
target-i386: Introduce set_cc_op

This will provide a good hook into which we can consolidate
all of the cc variable discards.

Signed-off-by: Richard Henderson <rth@twiddle.net>
target-i386: Don't clobber s->cc_op in gen_update_cc_op

Use a dirty flag to know whether env->cc_op is up to date,
rather than forcing s->cc_op to DYNAMIC and losing info.

Signed-off-by: Richard Henderson <rth@twiddle.net>
target-i386: Use gen_update_cc_op everywhere

All of the conditional calls to gen_op_set_cc_op go away, and
gen_op_set_cc_op itself gets inlined into its only remaining caller.

Signed-off-by: Richard Henderson <rth@twiddle.net>
target-i386: add helper functions to get other flags

Introduce new functions to extract PF, SF, OF, ZF in addition to CF.
These provide single entry points for optimizing accesses to a single
flag.

Reviewed-by: Blue Swirl <blauwirbel@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
target-i386: do not compute eflags multiple times consecutively

After calling gen_compute_eflags, leave the computed value in cc_reg_src
and set cc_op to CC_OP_EFLAGS.  The next few patches will remove anyway
most calls to gen_compute_eflags.

As a result of this change it is more natural to remove the register
argument from gen_compute_eflags and change all the callers.

Reviewed-by: Blue Swirl <blauwirbel@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
target-i386: no need to flush out cc_op before gen_eob

This makes code more similar to the other callers of gen_eob, especially
loopz/loopnz/jcxz.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
target-i386: Move CC discards to set_cc_op

This gets us universal coverage, rather than scattering discards
around at various places.  As a bonus, we do not emit redundant
discards e.g. between sequential logic insns.

Signed-off-by: Richard Henderson <rth@twiddle.net>