Re: [PATCH bpf-next 6/8] arm32, bpf: add support for 64 bit division instruction

On Tue, Sep 05, 2023 at 09:06:19PM +0000, Puranjay Mohan wrote:

+cont:

• /* Call appropriate function */
• if (sign)

• emit_mov_i(ARM_IP, op == BPF_DIV ? (u32)jit_sdiv64 : (u32)jit_smod64, ctx);
  

• else

• emit_mov_i(ARM_IP, op == BPF_DIV ? (u32)jit_udiv64 : (u32)jit_mod64, ctx);
  

Same comment as the previous patch here.

• emit_blx_r(ARM_IP, ctx);
• /* Save return value */
• if (rd[1] != ARM_R0) {

• emit(ARM_MOV_R(rd[0], ARM_R1), ctx);
  

• emit(ARM_MOV_R(rd[1], ARM_R0), ctx);
  

• }
• /* Recover {R1, R0} from stack if it is not Rd */
• if (rd[1] != ARM_R0)

• emit(ARM_POP(BIT(ARM_R0) | BIT(ARM_R1)), ctx);
  

• else

• emit(ARM_ADD_I(ARM_SP, ARM_SP, 8), ctx);
  

• /* Recover {R3, R2} from stack if it is not Rd */
• if (rd[1] != ARM_R2)

• emit(ARM_POP(BIT(ARM_R2) | BIT(ARM_R3)), ctx);
  

• else

• emit(ARM_ADD_I(ARM_SP, ARM_SP, 8), ctx);
  

if (rd[1] != ARM_R0) { emit(ARM_POP(BIT(ARM_R0) | BIT(ARM_R1)), ctx); emit(ARM_ADD_I(ARM_SP, ARM_SP, 8), ctx); } else if (rd[1] != ARM_R2) { emit(ARM_ADD_I(ARM_SP, ARM_SP, 8), ctx); emit(ARM_POP(BIT(ARM_R2) | BIT(ARM_R3)), ctx); } else { emit(ARM_ADD_I(ARM_SP, ARM_SP, 16), ctx); }

Hmm?