http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46098
Uros Bizjak <ubizjak at gmail dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|RESOLVED |ASSIGNED
Resolution|FIXED |
--- Comment #9 from Uros Bizjak <ubizjak at gmail dot com> 2012-05-14 18:13:50
UTC ---
(In reply to comment #8)
> Fixed.
This fix is not optimal, for the testcase we generate:
movsd (%rax), %xmm0
movhpd 8(%rax), %xmm0
movupd %xmm0, -16(%rbp)
movapd -16(%rbp), %xmm0
So, we move (unaligned!) memory to a register, and then use movupd to store to
aligned stack slot. Luckily, gcc figures that the load is from unaligned memory
and generates movsd/movhpd combo.
The intention was to generate:
movupd (%rax), %xmm0
movapd %xmm0, -16(%rbp)
movapd -16(%rbp), %xmm0
So, we don't want a fixup in the expander, but we should always load to a
register for "load" builtin class. The patch should be reverted and following
patch should be applied instead:
Index: i386.c
===================================================================
--- i386.c (revision 187465)
+++ i386.c (working copy)
@@ -29472,8 +29472,8 @@ ix86_expand_special_args_builtin (const struct bui
arg_adjust = 0;
if (optimize
|| target == 0
- || GET_MODE (target) != tmode
- || !insn_p->operand[0].predicate (target, tmode))
+ || !register_operand (target, tmode)
+ || GET_MODE (target) != tmode)
target = gen_reg_rtx (tmode);
}
I will undo the (arguably, small) damage in all release branches.
