On 12/09/2013 10:12 AM, Peter Maydell wrote:
> +static void do_gpr_ld(DisasContext *s, TCGv_i64 dest, TCGv_i64 tcg_addr,
> + int size, bool is_signed, bool extend)
> +{
> + switch (size) {
> + case 0:
> + if (is_signed) {
> + tcg_gen_qemu_ld8s(dest, tcg_addr, get_mem_index(s));
> + } else {
> + tcg_gen_qemu_ld8u(dest, tcg_addr, get_mem_index(s));
> + }
> + break;
> + case 1:
> + if (is_signed) {
> + tcg_gen_qemu_ld16s(dest, tcg_addr, get_mem_index(s));
> + } else {
> + tcg_gen_qemu_ld16u(dest, tcg_addr, get_mem_index(s));
> + }
> + break;
> + case 2:
> + if (is_signed) {
> + tcg_gen_qemu_ld32s(dest, tcg_addr, get_mem_index(s));
> + } else {
> + tcg_gen_qemu_ld32u(dest, tcg_addr, get_mem_index(s));
> + }
> + break;
> + case 3:
> + tcg_gen_qemu_ld64(dest, tcg_addr, get_mem_index(s));
> + break;
Likewise, combine all of this with tcg_gen_qemu_ld_i64.
> + if (extend && is_signed) {
> + g_assert(size < 3);
> + tcg_gen_ext32u_i64(dest, dest);
> + }
Is it worth noticing in size==2 && !extend that is_signed can be forced false
to avoid the extra extension.
> +static void handle_ldp(DisasContext *s, uint32_t insn)
> +{
> + int rt = extract32(insn, 0, 5);
> + int rn = extract32(insn, 5, 5);
> + int rt2 = extract32(insn, 10, 5);
> + int64_t offset = sextract32(insn, 15, 7);
> + int idx = extract32(insn, 23, 3);
> + bool is_signed = false;
> + bool is_vector = extract32(insn, 26, 1);
> + int opc = extract32(insn, 30, 2);
> + int size;
> + bool postindex = true;
> + bool wback = false;
> +
> + TCGv_i64 tcg_rt = cpu_reg(s, rt);
> + TCGv_i64 tcg_rt2 = cpu_reg(s, rt2);
> + TCGv_i64 tcg_addr;
> +
> + if (opc == 3) {
> + unallocated_encoding(s);
> + return;
> + }
> + if (is_vector) {
> + size = 2 + opc;
> + } else {
> + is_signed = opc & 1;
> + size = 2 + extract32(opc, 1, 1);
> + }
> +
> + switch (idx) {
> + case 1: /* post-index */
> + postindex = true;
> + wback = true;
> + break;
> + case 2: /* signed offset, rn not updated */
> + postindex = false;
> + break;
> + case 3: /* STP (pre-index) */
> + postindex = false;
> + wback = true;
> + break;
> + default: /* Failed decoder tree? */
> + unallocated_encoding(s);
> + break;
> + }
> +
> + offset <<= size;
> +
> + if (rn == 31) {
> + gen_check_sp_alignment(s);
> + }
> +
> + tcg_addr = tcg_temp_new_i64();
> + tcg_gen_mov_i64(tcg_addr, cpu_reg_sp(s, rn));
> +
> + if (!postindex) {
> + tcg_gen_addi_i64(tcg_addr, tcg_addr, offset);
> + }
> +
> + if (is_vector) {
> + do_fp_ld(s, rt, tcg_addr, size);
> + } else {
> + do_gpr_ld(s, tcg_rt, tcg_addr, size, is_signed, false);
> + }
> + tcg_gen_addi_i64(tcg_addr, tcg_addr, 1 << size);
> + if (is_vector) {
> + do_fp_ld(s, rt2, tcg_addr, size);
> + } else {
> + do_gpr_ld(s, tcg_rt2, tcg_addr, size, is_signed, false);
> + }
> +
> + if (wback) {
> + if (postindex) {
> + tcg_gen_addi_i64(tcg_addr, tcg_addr, offset - (1 << size));
> + } else {
> + tcg_gen_subi_i64(tcg_addr, tcg_addr, 1 << size);
> + }
> + tcg_gen_mov_i64(cpu_reg_sp(s, rn), tcg_addr);
> + }
> + tcg_temp_free_i64(tcg_addr);
> +}
There's so much overlap with STP, I think these ought not be separate
functions. Just merge the middle bit where the actual load/store happens.
r~
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