[PULL 04/24] target/i386: cleanup eob handling of RSM

Paolo Bonzini posted 24 patches 6 months ago
Maintainers: Gerd Hoffmann <kraxel@redhat.com>, "Marc-André Lureau" <marcandre.lureau@redhat.com>, Kevin Wolf <kwolf@redhat.com>, Hanna Reitz <hreitz@redhat.com>, Paolo Bonzini <pbonzini@redhat.com>, "Alex Bennée" <alex.bennee@linaro.org>, Thomas Huth <thuth@redhat.com>, "Daniel P. Berrangé" <berrange@redhat.com>, "Philippe Mathieu-Daudé" <philmd@linaro.org>, Hyman Huang <yong.huang@smartx.com>, Peter Xu <peterx@redhat.com>, Fabiano Rosas <farosas@suse.de>, Richard Henderson <richard.henderson@linaro.org>, Eduardo Habkost <eduardo@habkost.net>, Laurent Vivier <lvivier@redhat.com>
[PULL 04/24] target/i386: cleanup eob handling of RSM
Posted by Paolo Bonzini 6 months ago
gen_helper_rsm cannot generate an exception, and reloads the flags.
So there's no need to spill cc_op and update cpu_eip, but on the
other hand cc_op must be reset to CC_OP_EFLAGS before returning.

It all works by chance, because by spilling cc_op before the call
to the helper, it becomes non-dirty and gen_eob will not overwrite
the CC_OP_EFLAGS value that is placed there by the helper.  But
let's clean it up.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 target/i386/tcg/translate.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/target/i386/tcg/translate.c b/target/i386/tcg/translate.c
index 9782250b20b..849864d1aa2 100644
--- a/target/i386/tcg/translate.c
+++ b/target/i386/tcg/translate.c
@@ -4488,9 +4488,8 @@ static void disas_insn_old(DisasContext *s, CPUState *cpu, int b)
         /* we should not be in SMM mode */
         g_assert_not_reached();
 #else
-        gen_update_cc_op(s);
-        gen_update_eip_next(s);
         gen_helper_rsm(tcg_env);
+        set_cc_op(s, CC_OP_EFLAGS);
 #endif /* CONFIG_USER_ONLY */
         s->base.is_jmp = DISAS_EOB_ONLY;
         break;
-- 
2.45.1