From 11d0fc10b7efe3d0404a71e855c0d9f521ce3d66 Mon Sep 17 00:00:00 2001 From: Stefan Markovic Date: Thu, 2 Aug 2018 16:16:23 +0200 Subject: [PATCH] target/mips: Add emulation of nanoMIPS 32-bit branch instructions Add emulation of various flavors of nanoMIPS 32-bit branch instructions. Reviewed-by: Aleksandar Markovic Signed-off-by: Yongbok Kim Signed-off-by: Aleksandar Markovic Signed-off-by: Stefan Markovic --- target/mips/translate.c | 428 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 428 insertions(+) diff --git a/target/mips/translate.c b/target/mips/translate.c index 28d9d0c369..cae4ac0819 100644 --- a/target/mips/translate.c +++ b/target/mips/translate.c @@ -17217,6 +17217,321 @@ static void gen_pool32axf_nanomips_insn(CPUMIPSState *env, DisasContext *ctx) } } +/* Immediate Value Compact Branches */ +static void gen_compute_imm_branch(DisasContext *ctx, uint32_t opc, + int rt, int32_t imm, int32_t offset) +{ + TCGCond cond; + int bcond_compute = 0; + TCGv t0 = tcg_temp_new(); + TCGv t1 = tcg_temp_new(); + + gen_load_gpr(t0, rt); + tcg_gen_movi_tl(t1, imm); + ctx->btarget = addr_add(ctx, ctx->base.pc_next + 4, offset); + + /* Load needed operands and calculate btarget */ + switch (opc) { + case NM_BEQIC: + if (rt == 0 && imm == 0) { + /* Unconditional branch */ + } else if (rt == 0 && imm != 0) { + /* Treat as NOP */ + goto out; + } else { + bcond_compute = 1; + cond = TCG_COND_EQ; + } + break; + case NM_BBEQZC: + case NM_BBNEZC: + if (imm >= 32 && !(ctx->hflags & MIPS_HFLAG_64)) { + generate_exception_end(ctx, EXCP_RI); + goto out; + } else if (rt == 0 && opc == NM_BBEQZC) { + /* Unconditional branch */ + } else if (rt == 0 && opc == NM_BBNEZC) { + /* Treat as NOP */ + goto out; + } else { + tcg_gen_shri_tl(t0, t0, imm); + tcg_gen_andi_tl(t0, t0, 1); + tcg_gen_movi_tl(t1, 0); + bcond_compute = 1; + if (opc == NM_BBEQZC) { + cond = TCG_COND_EQ; + } else { + cond = TCG_COND_NE; + } + } + break; + case NM_BNEIC: + if (rt == 0 && imm == 0) { + /* Treat as NOP */ + goto out; + } else if (rt == 0 && imm != 0) { + /* Unconditional branch */ + } else { + bcond_compute = 1; + cond = TCG_COND_NE; + } + break; + case NM_BGEIC: + if (rt == 0 && imm == 0) { + /* Unconditional branch */ + } else { + bcond_compute = 1; + cond = TCG_COND_GE; + } + break; + case NM_BLTIC: + bcond_compute = 1; + cond = TCG_COND_LT; + break; + case NM_BGEIUC: + if (rt == 0 && imm == 0) { + /* Unconditional branch */ + } else { + bcond_compute = 1; + cond = TCG_COND_GEU; + } + break; + case NM_BLTIUC: + bcond_compute = 1; + cond = TCG_COND_LTU; + break; + default: + MIPS_INVAL("Immediate Value Compact branch"); + generate_exception_end(ctx, EXCP_RI); + goto out; + } + + if (bcond_compute == 0) { + /* Uncoditional compact branch */ + gen_goto_tb(ctx, 0, ctx->btarget); + } else { + /* Conditional compact branch */ + TCGLabel *fs = gen_new_label(); + + tcg_gen_brcond_tl(tcg_invert_cond(cond), t0, t1, fs); + + gen_goto_tb(ctx, 1, ctx->btarget); + gen_set_label(fs); + + gen_goto_tb(ctx, 0, ctx->base.pc_next + 4); + } + +out: + tcg_temp_free(t0); + tcg_temp_free(t1); +} + +/* P.BALRSC type nanoMIPS R6 branches: BALRSC and BRSC */ +static void gen_compute_nanomips_pbalrsc_branch(DisasContext *ctx, int rs, + int rt) +{ + TCGv t0 = tcg_temp_new(); + TCGv t1 = tcg_temp_new(); + + /* load rs */ + gen_load_gpr(t0, rs); + + /* link */ + if (rt != 0) { + tcg_gen_movi_tl(cpu_gpr[rt], ctx->base.pc_next + 4); + } + + /* calculate btarget */ + tcg_gen_shli_tl(t0, t0, 1); + tcg_gen_movi_tl(t1, ctx->base.pc_next + 4); + gen_op_addr_add(ctx, btarget, t1, t0); + + /* unconditional branch to register */ + tcg_gen_mov_tl(cpu_PC, btarget); + tcg_gen_lookup_and_goto_ptr(); + + tcg_temp_free(t0); + tcg_temp_free(t1); +} + +/* nanoMIPS Branches */ +static void gen_compute_compact_branch_nm(DisasContext *ctx, uint32_t opc, + int rs, int rt, int32_t offset) +{ + int bcond_compute = 0; + TCGv t0 = tcg_temp_new(); + TCGv t1 = tcg_temp_new(); + + /* Load needed operands and calculate btarget */ + switch (opc) { + /* compact branch */ + case OPC_BGEC: + case OPC_BLTC: + gen_load_gpr(t0, rs); + gen_load_gpr(t1, rt); + bcond_compute = 1; + ctx->btarget = addr_add(ctx, ctx->base.pc_next + 4, offset); + break; + case OPC_BGEUC: + case OPC_BLTUC: + if (rs == 0 || rs == rt) { + /* OPC_BLEZALC, OPC_BGEZALC */ + /* OPC_BGTZALC, OPC_BLTZALC */ + tcg_gen_movi_tl(cpu_gpr[31], ctx->base.pc_next + 4); + } + gen_load_gpr(t0, rs); + gen_load_gpr(t1, rt); + bcond_compute = 1; + ctx->btarget = addr_add(ctx, ctx->base.pc_next + 4, offset); + break; + case OPC_BC: + ctx->btarget = addr_add(ctx, ctx->base.pc_next + 4, offset); + break; + case OPC_BEQZC: + if (rs != 0) { + /* OPC_BEQZC, OPC_BNEZC */ + gen_load_gpr(t0, rs); + bcond_compute = 1; + ctx->btarget = addr_add(ctx, ctx->base.pc_next + 4, offset); + } else { + /* OPC_JIC, OPC_JIALC */ + TCGv tbase = tcg_temp_new(); + TCGv toffset = tcg_temp_new(); + + gen_load_gpr(tbase, rt); + tcg_gen_movi_tl(toffset, offset); + gen_op_addr_add(ctx, btarget, tbase, toffset); + tcg_temp_free(tbase); + tcg_temp_free(toffset); + } + break; + default: + MIPS_INVAL("Compact branch/jump"); + generate_exception_end(ctx, EXCP_RI); + goto out; + } + + if (bcond_compute == 0) { + /* Uncoditional compact branch */ + switch (opc) { + case OPC_BC: + gen_goto_tb(ctx, 0, ctx->btarget); + break; + default: + MIPS_INVAL("Compact branch/jump"); + generate_exception_end(ctx, EXCP_RI); + goto out; + } + } else { + /* Conditional compact branch */ + TCGLabel *fs = gen_new_label(); + + switch (opc) { + case OPC_BGEUC: + if (rs == 0 && rt != 0) { + /* OPC_BLEZALC */ + tcg_gen_brcondi_tl(tcg_invert_cond(TCG_COND_LE), t1, 0, fs); + } else if (rs != 0 && rt != 0 && rs == rt) { + /* OPC_BGEZALC */ + tcg_gen_brcondi_tl(tcg_invert_cond(TCG_COND_GE), t1, 0, fs); + } else { + /* OPC_BGEUC */ + tcg_gen_brcond_tl(tcg_invert_cond(TCG_COND_GEU), t0, t1, fs); + } + break; + case OPC_BLTUC: + if (rs == 0 && rt != 0) { + /* OPC_BGTZALC */ + tcg_gen_brcondi_tl(tcg_invert_cond(TCG_COND_GT), t1, 0, fs); + } else if (rs != 0 && rt != 0 && rs == rt) { + /* OPC_BLTZALC */ + tcg_gen_brcondi_tl(tcg_invert_cond(TCG_COND_LT), t1, 0, fs); + } else { + /* OPC_BLTUC */ + tcg_gen_brcond_tl(tcg_invert_cond(TCG_COND_LTU), t0, t1, fs); + } + break; + case OPC_BGEC: + if (rs == 0 && rt != 0) { + /* OPC_BLEZC */ + tcg_gen_brcondi_tl(tcg_invert_cond(TCG_COND_LE), t1, 0, fs); + } else if (rs != 0 && rt != 0 && rs == rt) { + /* OPC_BGEZC */ + tcg_gen_brcondi_tl(tcg_invert_cond(TCG_COND_GE), t1, 0, fs); + } else { + /* OPC_BGEC */ + tcg_gen_brcond_tl(tcg_invert_cond(TCG_COND_GE), t0, t1, fs); + } + break; + case OPC_BLTC: + if (rs == 0 && rt != 0) { + /* OPC_BGTZC */ + tcg_gen_brcondi_tl(tcg_invert_cond(TCG_COND_GT), t1, 0, fs); + } else if (rs != 0 && rt != 0 && rs == rt) { + /* OPC_BLTZC */ + tcg_gen_brcondi_tl(tcg_invert_cond(TCG_COND_LT), t1, 0, fs); + } else { + /* OPC_BLTC */ + tcg_gen_brcond_tl(tcg_invert_cond(TCG_COND_LT), t0, t1, fs); + } + break; + case OPC_BEQZC: + tcg_gen_brcondi_tl(tcg_invert_cond(TCG_COND_EQ), t0, 0, fs); + break; + default: + MIPS_INVAL("Compact conditional branch/jump"); + generate_exception_end(ctx, EXCP_RI); + goto out; + } + + /* Generating branch here as compact branches don't have delay slot */ + gen_goto_tb(ctx, 1, ctx->btarget); + gen_set_label(fs); + + gen_goto_tb(ctx, 0, ctx->base.pc_next + 4); + } + +out: + tcg_temp_free(t0); + tcg_temp_free(t1); +} + + +/* nanoMIPS CP1 Branches */ +static void gen_compute_branch_cp1_nm(DisasContext *ctx, uint32_t op, + int32_t ft, int32_t offset) +{ + target_ulong btarget; + TCGv_i64 t0 = tcg_temp_new_i64(); + + gen_load_fpr64(ctx, t0, ft); + tcg_gen_andi_i64(t0, t0, 1); + + btarget = addr_add(ctx, ctx->base.pc_next + 4, offset); + + switch (op) { + case NM_BC1EQZC: + tcg_gen_xori_i64(t0, t0, 1); + ctx->hflags |= MIPS_HFLAG_BC; + break; + case NM_BC1NEZC: + /* t0 already set */ + ctx->hflags |= MIPS_HFLAG_BC; + break; + default: + MIPS_INVAL("cp1 cond branch"); + generate_exception_end(ctx, EXCP_RI); + goto out; + } + + tcg_gen_trunc_i64_tl(bcond, t0); + + ctx->btarget = btarget; + +out: + tcg_temp_free_i64(t0); +} + static void gen_p_lsx(DisasContext *ctx, int rd, int rs, int rt) { @@ -18276,16 +18591,129 @@ static int decode_nanomips_32_48_opc(CPUMIPSState *env, DisasContext *ctx) } break; case NM_MOVE_BALC: + { + TCGv t0 = tcg_temp_new(); + int32_t s = sextract32(ctx->opcode, 0, 1) << 21 | + extract32(ctx->opcode, 1, 20) << 1; + rd = (extract32(ctx->opcode, 24, 1)) == 0 ? 4 : 5; + rt = decode_gpr_gpr4_zero(extract32(ctx->opcode, 25, 1) << 3 | + extract32(ctx->opcode, 21, 3)); + gen_load_gpr(t0, rt); + tcg_gen_mov_tl(cpu_gpr[rd], t0); + gen_compute_branch_nm(ctx, OPC_BGEZAL, 4, 0, 0, s); + tcg_temp_free(t0); + } break; case NM_P_BAL: + { + int32_t s = sextract32(ctx->opcode, 0, 1) << 25 | + extract32(ctx->opcode, 1, 24) << 1; + + if ((extract32(ctx->opcode, 25, 1)) == 0) { + /* BC */ + gen_compute_branch_nm(ctx, OPC_BEQ, 4, 0, 0, s); + } else { + /* BALC */ + gen_compute_branch_nm(ctx, OPC_BGEZAL, 4, 0, 0, s); + } + } break; case NM_P_J: + switch (extract32(ctx->opcode, 12, 4)) { + case NM_JALRC: + case NM_JALRC_HB: + gen_compute_branch_nm(ctx, OPC_JALR, 4, rs, rt, 0); + break; + case NM_P_BALRSC: + gen_compute_nanomips_pbalrsc_branch(ctx, rs, rt); + break; + default: + generate_exception_end(ctx, EXCP_RI); + break; + } break; case NM_P_BR1: + { + int32_t s = sextract32(ctx->opcode, 0, 1) << 14 | + extract32(ctx->opcode, 1, 13) << 1; + switch (extract32(ctx->opcode, 14, 2)) { + case NM_BEQC: + gen_compute_branch_nm(ctx, OPC_BEQ, 4, rs, rt, s); + break; + case NM_P_BR3A: + s = sextract32(ctx->opcode, 0, 1) << 14 | + extract32(ctx->opcode, 1, 13) << 1; + check_cp1_enabled(ctx); + switch (extract32(ctx->opcode, 16, 5)) { + case NM_BC1EQZC: + gen_compute_branch_cp1_nm(ctx, OPC_BC1EQZ, rt, s); + break; + case NM_BC1NEZC: + gen_compute_branch_cp1_nm(ctx, OPC_BC1NEZ, rt, s); + break; + default: + generate_exception_end(ctx, EXCP_RI); + break; + } + break; + case NM_BGEC: + if (rs == rt) { + gen_compute_compact_branch_nm(ctx, OPC_BC, rs, rt, s); + } else { + gen_compute_compact_branch_nm(ctx, OPC_BGEC, rs, rt, s); + } + break; + case NM_BGEUC: + if (rs == rt || rt == 0) { + gen_compute_compact_branch_nm(ctx, OPC_BC, 0, 0, s); + } else if (rs == 0) { + gen_compute_compact_branch_nm(ctx, OPC_BEQZC, rt, 0, s); + } else { + gen_compute_compact_branch_nm(ctx, OPC_BGEUC, rs, rt, s); + } + break; + } + } break; case NM_P_BR2: + { + int32_t s = sextract32(ctx->opcode, 0, 1) << 14 | + extract32(ctx->opcode, 1, 13) << 1; + switch (extract32(ctx->opcode, 14, 2)) { + case NM_BNEC: + gen_compute_branch_nm(ctx, OPC_BNE, 4, rs, rt, s); + break; + case NM_BLTC: + if (rs != 0 && rt != 0 && rs == rt) { + /* NOP */ + ctx->hflags |= MIPS_HFLAG_FBNSLOT; + } else { + gen_compute_compact_branch_nm(ctx, OPC_BLTC, rs, rt, s); + } + break; + case NM_BLTUC: + if (rs == 0 || rs == rt) { + /* NOP */ + ctx->hflags |= MIPS_HFLAG_FBNSLOT; + } else { + gen_compute_compact_branch_nm(ctx, OPC_BLTUC, rs, rt, s); + } + break; + default: + generate_exception_end(ctx, EXCP_RI); + break; + } + } break; case NM_P_BRI: + { + int32_t s = sextract32(ctx->opcode, 0, 1) << 11 | + extract32(ctx->opcode, 1, 10) << 1; + uint32_t u = extract32(ctx->opcode, 11, 7); + + gen_compute_imm_branch(ctx, extract32(ctx->opcode, 18, 3), + rt, u, s); + } break; default: generate_exception_end(ctx, EXCP_RI);