Although there's no fundamental reason why shrink wrapping and
speculation tracking are incompatible, a phase-ordering requirement (we
need to do speculation tracking before the final basic block clean-up)
means that the shrink wrapping pass can undo some of the changes the
speculation tracking pass makes. The result is that the tracking, while
still safe is less comprehensive than we really want.
So to keep things simple, and because the tracking code is quite
expensive anyway, it seems best to just disable that pass when we are
tracking speculative execution.
* config/aarch64/aarch64.c (aarch64_override_options): Disable
shrink-wrapping when -mtrack-speculation.
Committed.
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index 54f57463e97..d356fa37823 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -11346,6 +11346,12 @@ aarch64_override_options (void)
|| (aarch64_arch_string && valid_arch))
gcc_assert (explicit_arch != aarch64_no_arch);
+ /* The pass to insert speculation tracking runs before
+ shrink-wrapping and the latter does not know how to update the
+ tracking status. So disable it in this case. */
+ if (aarch64_track_speculation)
+ flag_shrink_wrap = 0;
+
aarch64_override_options_internal (&global_options);
/* Save these options as the default ones in case we push and pop them later
