s390x, build-oss-fuzz and Clang -fsanitize=undefined fixes

[PULL 05/22] target/s390x: Disable conditional branch-to-next for PER

Thomas Huth posted 22 patches 5 months, 4 weeks ago

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Maintainers: Halil Pasic <pasic@linux.ibm.com>, Christian Borntraeger <borntraeger@linux.ibm.com>, David Hildenbrand <david@redhat.com>, Eric Farman <farman@linux.ibm.com>, Thomas Huth <thuth@redhat.com>, Markus Armbruster <armbru@redhat.com>, Michael Roth <michael.roth@amd.com>, Alexander Bulekov <alxndr@bu.edu>, Paolo Bonzini <pbonzini@redhat.com>, Bandan Das <bsd@redhat.com>, Stefan Hajnoczi <stefanha@redhat.com>, Darren Kenny <darren.kenny@oracle.com>, Qiuhao Li <Qiuhao.Li@outlook.com>, "Michael S. Tsirkin" <mst@redhat.com>, Cornelia Huck <cohuck@redhat.com>, Richard Henderson <richard.henderson@linaro.org>, Ilya Leoshkevich <iii@linux.ibm.com>, Laurent Vivier <lvivier@redhat.com>

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[PULL 05/22] target/s390x: Disable conditional branch-to-next for PER

Posted by Thomas Huth 5 months, 4 weeks ago

From: Richard Henderson <richard.henderson@linaro.org>

For PER, we require a conditional call to helper_per_branch
for the conditional branch.  Fold the remaining optimization
into a call to helper_goto_direct, which will take care of
the remaining gbea adjustment.

Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20240502054417.234340-6-richard.henderson@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 target/s390x/tcg/translate.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/target/s390x/tcg/translate.c b/target/s390x/tcg/translate.c
index de98115c4d..07620948ae 100644
--- a/target/s390x/tcg/translate.c
+++ b/target/s390x/tcg/translate.c
@@ -1131,13 +1131,13 @@ static DisasJumpType help_branch(DisasContext *s, DisasCompare *c,
         goto egress;
     }
     if (is_imm) {
-        if (dest == s->pc_tmp) {
-            /* Branch to next.  */
-            per_branch(s, true);
-            ret = DISAS_NEXT;
-            goto egress;
-        }
-        if (c->cond == TCG_COND_ALWAYS) {
+        /*
+         * Do not optimize a conditional branch if PER enabled, because we
+         * still need a conditional call to helper_per_branch.
+         */
+        if (c->cond == TCG_COND_ALWAYS
+            || (dest == s->pc_tmp &&
+                !(s->base.tb->flags & FLAG_MASK_PER_BRANCH))) {
             ret = help_goto_direct(s, dest);
             goto egress;
         }
-- 
2.45.1