HELP: combine 2 insn error

[Jianzhang Peng]

I merge two  SET insns to a PARALLEL before gcc's schedule_insns () in
pass_sched .
Would you please tell me where is the bug?
Thanks!


CODE:

void merge(rtx insn1,rtx insn2)
{
        rtx parallel;
        parallel = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (2));
        XVECEXP (par, 0, 0) = PATTERN(insn1);
        XVECEXP (par, 0, 1) = PATTERN(insn2);
        PATTERN(insn1) = parallel;
        delete_insn(insn2);
}

GDB REPORT

0x000000000067aa5c in constrain_operands (strict=0) at
../../gcc-4.4.0/gcc/recog.c:2306
2306              enum machine_mode mode = GET_MODE (op);
(gdb) bt
#0  0x000000000067aa5c in constrain_operands (strict=0) at
../../gcc-4.4.0/gcc/recog.c:2306
#1  0x0000000000679f17 in extract_constrain_insn_cached
(insn=0x2a961a3d20) at ../../gcc-4.4.0/gcc/recog.c:1965
#2  0x00000000008f2423 in insn_default_latency (insn=0x2a961a3d20) at
../../gcc-4.4.0/gcc/config/mips/mips.md:584
#3  0x0000000000a238b9 in insn_cost (insn=0x2a961a3d20) at
../../gcc-4.4.0/gcc/haifa-sched.c:636
#4  0x0000000000a239de in dep_cost_1 (link=0xf69120, dw=0) at
../../gcc-4.4.0/gcc/haifa-sched.c:670
#5  0x0000000000a23b00 in dep_cost (link=0xf69120) at
../../gcc-4.4.0/gcc/haifa-sched.c:725
#6  0x0000000000a23d8f in priority (insn=0x2a961a3d20) at
../../gcc-4.4.0/gcc/haifa-sched.c:834
#7  0x0000000000a275ca in set_priorities (head=0x2a961a3cd0,
tail=0x2a961933c0) at ../../gcc-4.4.0/gcc/haifa-sched.c:2830
#8  0x00000000006d0c2e in compute_priorities () at
../../gcc-4.4.0/gcc/sched-rgn.c:3220
#9  0x00000000006d0c97 in schedule_region (rgn=0) at
../../gcc-4.4.0/gcc/sched-rgn.c:3249
#10 0x00000000006d1a69 in schedule_insns () at
../../gcc-4.4.0/gcc/sched-rgn.c:3662
#11 0x00000000006d22de in rest_of_handle_sched () at
../../gcc-4.4.0/gcc/sched-rgn.c:3861
#12 0x0000000000657289 in execute_one_pass (pass=0xdca020) at
../../gcc-4.4.0/gcc/passes.c:1278
#13 0x0000000000657471 in execute_pass_list (pass=0xdca020) at
../../gcc-4.4.0/gcc/passes.c:1327
#14 0x000000000065748d in execute_pass_list (pass=0xdc8ce0) at
../../gcc-4.4.0/gcc/passes.c:1328
#15 0x0000000000769feb in tree_rest_of_compilation
(fndecl=0x2a96155f00) at ../../gcc-4.4.0/gcc/tree-optimize.c:420
#16 0x00000000008b2830 in cgraph_expand_function (node=0x2a96181000)
at ../../gcc-4.4.0/gcc/cgraphunit.c:1047
#17 0x00000000008b2a0c in cgraph_expand_all_functions () at
../../gcc-4.4.0/gcc/cgraphunit.c:1106
#18 0x00000000008b2f9e in cgraph_optimize () at
../../gcc-4.4.0/gcc/cgraphunit.c:1311
#19 0x000000000041a386 in c_write_global_declarations () at
../../gcc-4.4.0/gcc/c-decl.c:8102
#20 0x000000000071face in compile_file () at ../../gcc-4.4.0/gcc/toplev.c:981
#21 0x0000000000721527 in do_compile () at ../../gcc-4.4.0/gcc/toplev.c:2193
#22 0x0000000000721589 in toplev_main (argc=8, argv=0x7fbffff8c8) at
../../gcc-4.4.0/gcc/toplev.c:2225
#23 0x000000000047d63b in main (argc=8, argv=0x7fbffff8c8) at
../../gcc-4.4.0/gcc/main.c:35


-- 
Jianzhang Peng