> Attached patch was actually tested on a couple of cases. It generates > the same assembly as before.
Note that you could just remove the second ":W" in the define_insn pattern. That's better, but not quite it because this segfaults at -O2: #0 memory_operand (op=0xabababababababab, mode=mode@entry=VOIDmode) at /home/eric/svn/gcc/gcc/recog.c:1360 #1 0x00000000014388b1 in get_attr_memory (insn=insn@entry=0x7ffff697b8c0) at /home/eric/svn/gcc/gcc/config/i386/i386.md:2120 #2 0x0000000001636fb8 in insn_default_latency_generic (insn=0x7ffff697b8c0) at /home/eric/svn/gcc/gcc/config/i386/i386.md:27394 #3 0x00000000017f9695 in insn_cost (insn=0x7ffff697b8c0) at /home/eric/svn/gcc/gcc/haifa-sched.c:1415 #4 0x00000000017feb75 in dep_cost_1 (link=link@entry=0x2e962e8, dw=dw@entry=0) at /home/eric/svn/gcc/gcc/haifa-sched.c:1468 #5 0x0000000001800d7a in dep_cost (link=0x2e962e8) at /home/eric/svn/gcc/gcc/haifa-sched.c:1523 #6 priority (insn=0x7ffff697b8c0) at /home/eric/svn/gcc/gcc/haifa- sched.c:1674 #7 0x0000000001800e6f in set_priorities (head=<optimized out>, tail=<optimized out>) at /home/eric/svn/gcc/gcc/haifa-sched.c:7209 #8 0x0000000000f689e3 in compute_priorities () at /home/eric/svn/gcc/gcc/sched-rgn.c:3022 #9 0x0000000000f6bc46 in schedule_region (rgn=0) at /home/eric/svn/gcc/gcc/sched-rgn.c:3115 #10 schedule_insns () at /home/eric/svn/gcc/gcc/sched-rgn.c:3513 #11 0x0000000000f6c4de in schedule_insns () (gdb) frame 1 #1 0x00000000014388b1 in get_attr_memory (insn=insn@entry=0x7ffff697b8c0) at /home/eric/svn/gcc/gcc/config/i386/i386.md:2120 2120 (match_test "TARGET_AVX") (gdb) p debug_rtx(insn) (insn 779 927 928 2 (parallel [ (set (mem/v:DI (reg/f:DI 7 sp) [0 S8 A8]) (unspec:DI [ (const_int 0 [0]) ] UNSPEC_PROBE_STACK)) (clobber (reg:CC 17 flags)) ]) c52104y.adb:57 1005 {probe_stack_di} (expr_list:REG_UNUSED (reg:CC 17 flags) (nil))) $1 = void -- Eric Botcazou