While m68k does have branch prediction, it's a dead architecture, does
not have out of order properties and AFAIK doesn't have a suitably
accurate timer. Thus, it doesn't seem worth trying to do any spectre v1
mitigations.
Committed to the trunk.
Jeff
commit 78095ef84bbe24cd371a4a3baeaf83944efac6a2
Author: law <law@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Thu Aug 2 17:50:16 2018 +0000
PR target/86790
* config/m68k/m68k.c (TARGET_HAVE_SPECULATION_SAFE_VALUE):
Define to speculation_safe_value_not_needed.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@263272
138bc75d-0d04-0410-961f-82ee72b054a4
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 06db972e5d6..762e14ef224 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,9 @@
2018-08-02 Jeff Law <l...@redhat.com>
+ PR target/86790
+ * config/m68k/m68k.c (TARGET_HAVE_SPECULATION_SAFE_VALUE):
+ Define to speculation_safe_value_not_needed.
+
PR target/86784
* config/h8300/h8300.c (TARGET_HAVE_SPECULATION_SAFE_VALUE):
Define to speculation_safe_value_not_needed.
diff --git a/gcc/config/m68k/m68k.c b/gcc/config/m68k/m68k.c
index ef8604ebe3d..75a5a5b69b9 100644
--- a/gcc/config/m68k/m68k.c
+++ b/gcc/config/m68k/m68k.c
@@ -353,6 +353,9 @@ static machine_mode m68k_promote_function_mode (const_tree,
machine_mode,
#undef TARGET_PROMOTE_FUNCTION_MODE
#define TARGET_PROMOTE_FUNCTION_MODE m68k_promote_function_mode
+#undef TARGET_HAVE_SPECULATION_SAFE_VALUE
+#define TARGET_HAVE_SPECULATION_SAFE_VALUE speculation_safe_value_not_needed
+
static const struct attribute_spec m68k_attribute_table[] =
{
/* { name, min_len, max_len, decl_req, type_req, fn_type_req,
