Re: [PATCH 1/4][V4][RISC-V] support cm.push cm.pop cm.popret in zcmp

[Kito Cheng via Gcc-patches]

Hi Fei:

Tried to use Jiawei's patch to test this patch and found some issue:


> @@ -5430,13 +5632,15 @@ riscv_expand_prologue (void)
>    /* Save the registers.  */
>    if ((frame->mask | frame->fmask) != 0)
>      {
> -      HOST_WIDE_INT step1 = riscv_first_stack_step (frame, remaining_size);
> -
> -      insn = gen_add3_insn (stack_pointer_rtx,
> -                           stack_pointer_rtx,
> -                           GEN_INT (-step1));
> -      RTX_FRAME_RELATED_P (emit_insn (insn)) = 1;
> -      remaining_size -= step1;
> +      if (known_gt (remaining_size, frame->frame_pointer_offset))
> +        {
> +          HOST_WIDE_INT step1 = riscv_first_stack_step (frame, 
> remaining_size);
> +          remaining_size -= step1;
> +          insn = gen_add3_insn (stack_pointer_rtx,
> +                                stack_pointer_rtx,
> +                                GEN_INT (-step1));
> +          RTX_FRAME_RELATED_P (emit_insn (insn)) = 1;
> +        }
>        riscv_for_each_saved_reg (remaining_size, riscv_save_reg, false, 
> false);
>      }
>

I hit some issue here during building libgcc, I use
riscv-gnu-toolchain with --with-arch=rv64gzca_zcmp

And the error message is:

In file included from
../../../../../riscv-gnu-toolchain-trunk/gcc/libgcc/unwind-dw2.c:1471:
../../../../../riscv-gnu-toolchain-trunk/gcc/libgcc/unwind.inc: In
function '_Unwind_Backtrace':
../../../../../riscv-gnu-toolchain-trunk/gcc/libgcc/unwind.inc:330:1:
internal compiler error: in gen_reg_rtx, at emit-rtl.cc:1176
 330 | }
     | ^
0x83753a gen_reg_rtx(machine_mode)
       ../../../../riscv-gnu-toolchain-trunk/gcc/gcc/emit-rtl.cc:1176
0xf5566f maybe_legitimize_operand
       ../../../../riscv-gnu-toolchain-trunk/gcc/gcc/optabs.cc:8047
0xf5566f maybe_legitimize_operands(insn_code, unsigned int, unsigned
int, expand_operand*)
       ../../../../riscv-gnu-toolchain-trunk/gcc/gcc/optabs.cc:8191
0xf511d9 maybe_gen_insn(insn_code, unsigned int, expand_operand*)
       ../../../../riscv-gnu-toolchain-trunk/gcc/gcc/optabs.cc:8210
0xf58539 expand_binop_directly
       ../../../../riscv-gnu-toolchain-trunk/gcc/gcc/optabs.cc:1452
0xf56666 expand_binop(machine_mode, optab_tag, rtx_def*, rtx_def*,
rtx_def*, int, optab_methods)
       ../../../../riscv-gnu-toolchain-trunk/gcc/gcc/optabs.cc:1539
0xcbfdd0 force_operand(rtx_def*, rtx_def*)
       ../../../../riscv-gnu-toolchain-trunk/gcc/gcc/expr.cc:8231
0xc8fca1 force_reg(machine_mode, rtx_def*)
       ../../../../riscv-gnu-toolchain-trunk/gcc/gcc/explow.cc:687
0x144b8cd riscv_force_temporary
       ../../../../riscv-gnu-toolchain-trunk/gcc/gcc/config/riscv/riscv.cc:1531
0x144b8cd riscv_force_address
       ../../../../riscv-gnu-toolchain-trunk/gcc/gcc/config/riscv/riscv.cc:1528
0x144b8cd riscv_legitimize_move(machine_mode, rtx_def*, rtx_def*)
       ../../../../riscv-gnu-toolchain-trunk/gcc/gcc/config/riscv/riscv.cc:2387
0x1af063e gen_movdf(rtx_def*, rtx_def*)
       ../../../../riscv-gnu-toolchain-trunk/gcc/gcc/config/riscv/riscv.md:2107
0xcba503 rtx_insn* insn_gen_fn::operator()<rtx_def*,
rtx_def*>(rtx_def*, rtx_def*) const
       ../../../../riscv-gnu-toolchain-trunk/gcc/gcc/recog.h:411
0xcba503 emit_move_insn_1(rtx_def*, rtx_def*)
       ../../../../riscv-gnu-toolchain-trunk/gcc/gcc/expr.cc:4164
0x143d6c4 riscv_emit_move(rtx_def*, rtx_def*)
       ../../../../riscv-gnu-toolchain-trunk/gcc/gcc/config/riscv/riscv.cc:1486
0x143d6c4 riscv_save_reg
       ../../../../riscv-gnu-toolchain-trunk/gcc/gcc/config/riscv/riscv.cc:5715
0x143e2b9 riscv_for_each_saved_reg
       ../../../../riscv-gnu-toolchain-trunk/gcc/gcc/config/riscv/riscv.cc:5904
0x14480d0 riscv_expand_prologue()
       ../../../../riscv-gnu-toolchain-trunk/gcc/gcc/config/riscv/riscv.cc:6156
0x1af57fb gen_prologue()
       ../../../../riscv-gnu-toolchain-trunk/gcc/gcc/config/riscv/riscv.md:2816
0x143c746 target_gen_prologue
       ../../../../riscv-gnu-toolchain-trunk/gcc/gcc/config/riscv/riscv.md:3302


Reduced case:

$ riscv64-unknown-elf-gcc -march=rv64imafd_zicsr_zifencei_zca_zcmp
-mabi=lp64d  unwind-dw2.i -Os

typedef struct {
 struct {
   struct {
     struct {
       long a
     }
   } a[129]
 }
} b;
struct c {
 void *a[129]
} d() {
 struct c a;
 __builtin_unwind_init();
 b e;
 f(a, &e);
}