diff options
Diffstat (limited to 'gcc/explow.c')
| -rw-r--r-- | gcc/explow.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/gcc/explow.c b/gcc/explow.c index 984150efd05..11dffedd4b0 100644 --- a/gcc/explow.c +++ b/gcc/explow.c @@ -1062,6 +1062,20 @@ emit_stack_restore (enum save_level save_level, rtx sa) /* The default is that we use a move insn. */ rtx (*fcn) (rtx, rtx) = gen_move_insn; + /* If stack_realign_drap, the x86 backend emits a prologue that aligns both + STACK_POINTER and HARD_FRAME_POINTER. + If stack_realign_fp, the x86 backend emits a prologue that aligns only + STACK_POINTER. This renders the HARD_FRAME_POINTER unusable for accessing + aligned variables, which is reflected in ix86_can_eliminate. + We normally still have the realigned STACK_POINTER that we can use. + But if there is a stack restore still present at reload, it can trigger + mark_not_eliminable for the STACK_POINTER, leaving no way to eliminate + FRAME_POINTER into a hard reg. + To prevent this situation, we force need_drap if we emit a stack + restore. */ + if (SUPPORTS_STACK_ALIGNMENT) + crtl->need_drap = true; + /* See if this machine has anything special to do for this kind of save. */ switch (save_level) { |