* regrename.h (struct du_head): Add target_data_1 and target_data_2

	fields.
	* regrename.c (create_new_chain): Clear entire struct after allocating.

	* config/i386/i386.opt (mmitigate-rop): New option.
	* doc/invoke.texi (mmitigate-rop): Document.
	* config/i386/i386.c: Include "regrename.h".
	(ix86_rop_should_change_byte_p, reg_encoded_number,
	ix86_get_modrm_for_rop, set_rop_modrm_reg_bits, ix86_mitigate_rop): New
	static functions.
	(ix86_reorg): Call ix86_mitigate_rop if -fmitigate-rop.
	* config/i386/i386.md (attr "modrm_class"): New.
	(cmp<mode>_ccno_1, mov<mode>_xor, movstrict<mode>_xor,
	x86_mov<mode>cc_0_m1. x86_mov<mode>cc_0_m1_se)
	(x86_mov<mode>cc_0_m1_neg): Override modrm_class attribute.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@230543 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 1 insertions, 4 deletions

diff --git a/gcc/regrename.c b/gcc/regrename.c
index 1f11695c5db..e2a1e83c7ea 100644
--- a/gcc/regrename.c
+++ b/gcc/regrename.c
@@ -227,13 +227,10 @@ create_new_chain (unsigned this_regno, unsigned this_nregs, rtx *loc,
   struct du_chain *this_du;
   int nregs;
 
+  memset (head, 0, sizeof *head);
   head->next_chain = open_chains;
   head->regno = this_regno;
   head->nregs = this_nregs;
-  head->need_caller_save_reg = 0;
-  head->cannot_rename = 0;
-  head->renamed = 0;
-  head->tied_chain = NULL;
 
   id_to_chain.safe_push (head);
   head->id = current_id++;