From 7eed8e4003532c49dcd7639086a4895029151f41 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Thu, 21 Apr 2022 08:17:16 -0700 Subject: [PATCH] target/nios2: Introduce dest_gpr Constrain all references to cpu_R[] to load_gpr and dest_gpr. This will be required for supporting shadow register sets. Reviewed-by: Peter Maydell Signed-off-by: Richard Henderson Message-Id: <20220421151735.31996-46-richard.henderson@linaro.org> --- target/nios2/translate.c | 144 ++++++++++++++++------------------------------- 1 file changed, 49 insertions(+), 95 deletions(-) diff --git a/target/nios2/translate.c b/target/nios2/translate.c index f2dcaa3fbb..e2742a8556 100644 --- a/target/nios2/translate.c +++ b/target/nios2/translate.c @@ -128,6 +128,7 @@ typedef struct DisasContext { DisasContextBase base; target_ulong pc; int mem_idx; + TCGv sink; const ControlRegState *cr_state; } DisasContext; @@ -160,6 +161,18 @@ static TCGv load_gpr(DisasContext *dc, unsigned reg) return cpu_R[reg]; } +static TCGv dest_gpr(DisasContext *dc, unsigned reg) +{ + assert(reg < NUM_GP_REGS); + if (unlikely(reg == R_ZERO)) { + if (dc->sink == NULL) { + dc->sink = tcg_temp_new(); + } + return dc->sink; + } + return cpu_R[reg]; +} + static void t_gen_helper_raise_exception(DisasContext *dc, uint32_t index) { @@ -218,7 +231,7 @@ static void jmpi(DisasContext *dc, uint32_t code, uint32_t flags) static void call(DisasContext *dc, uint32_t code, uint32_t flags) { - tcg_gen_movi_tl(cpu_R[R_RA], dc->base.pc_next); + tcg_gen_movi_tl(dest_gpr(dc, R_RA), dc->base.pc_next); jmpi(dc, code, flags); } @@ -231,27 +244,10 @@ static void gen_ldx(DisasContext *dc, uint32_t code, uint32_t flags) I_TYPE(instr, code); TCGv addr = tcg_temp_new(); - TCGv data; - - /* - * WARNING: Loads into R_ZERO are ignored, but we must generate the - * memory access itself to emulate the CPU precisely. Load - * from a protected page to R_ZERO will cause SIGSEGV on - * the Nios2 CPU. - */ - if (likely(instr.b != R_ZERO)) { - data = cpu_R[instr.b]; - } else { - data = tcg_temp_new(); - } + TCGv data = dest_gpr(dc, instr.b); tcg_gen_addi_tl(addr, load_gpr(dc, instr.a), instr.imm16.s); tcg_gen_qemu_ld_tl(data, addr, dc->mem_idx, flags); - - if (unlikely(instr.b == R_ZERO)) { - tcg_temp_free(data); - } - tcg_temp_free(addr); } @@ -281,7 +277,7 @@ static void gen_bxx(DisasContext *dc, uint32_t code, uint32_t flags) I_TYPE(instr, code); TCGLabel *l1 = gen_new_label(); - tcg_gen_brcond_tl(flags, cpu_R[instr.a], cpu_R[instr.b], l1); + tcg_gen_brcond_tl(flags, load_gpr(dc, instr.a), load_gpr(dc, instr.b), l1); gen_goto_tb(dc, 0, dc->base.pc_next); gen_set_label(l1); gen_goto_tb(dc, 1, dc->base.pc_next + (instr.imm16.s & -4)); @@ -293,11 +289,8 @@ static void do_i_cmpxx(DisasContext *dc, uint32_t insn, TCGCond cond, ImmFromIType *imm) { I_TYPE(instr, insn); - - if (likely(instr.b != R_ZERO)) { - tcg_gen_setcondi_tl(cond, cpu_R[instr.b], - load_gpr(dc, instr.a), imm(&instr)); - } + tcg_gen_setcondi_tl(cond, dest_gpr(dc, instr.b), + load_gpr(dc, instr.a), imm(&instr)); } #define gen_i_cmpxx(fname, imm) \ @@ -324,9 +317,9 @@ static void do_i_math_logic(DisasContext *dc, uint32_t insn, if (instr.a == R_ZERO) { /* This catches the canonical expansions of movi and movhi. */ - tcg_gen_movi_tl(cpu_R[instr.b], x_op_0_eq_x ? val : 0); + tcg_gen_movi_tl(dest_gpr(dc, instr.b), x_op_0_eq_x ? val : 0); } else { - fn(cpu_R[instr.b], cpu_R[instr.a], val); + fn(dest_gpr(dc, instr.b), load_gpr(dc, instr.a), val); } } @@ -434,7 +427,7 @@ static void eret(DisasContext *dc, uint32_t code, uint32_t flags) #else TCGv tmp = tcg_temp_new(); tcg_gen_ld_tl(tmp, cpu_env, offsetof(CPUNios2State, ctrl[CR_ESTATUS])); - gen_helper_eret(cpu_env, tmp, cpu_R[R_EA]); + gen_helper_eret(cpu_env, tmp, load_gpr(dc, R_EA)); tcg_temp_free(tmp); dc->base.is_jmp = DISAS_NORETURN; @@ -444,8 +437,7 @@ static void eret(DisasContext *dc, uint32_t code, uint32_t flags) /* PC <- ra */ static void ret(DisasContext *dc, uint32_t code, uint32_t flags) { - tcg_gen_mov_tl(cpu_pc, cpu_R[R_RA]); - + tcg_gen_mov_tl(cpu_pc, load_gpr(dc, R_RA)); dc->base.is_jmp = DISAS_JUMP; } @@ -464,7 +456,7 @@ static void bret(DisasContext *dc, uint32_t code, uint32_t flags) #else TCGv tmp = tcg_temp_new(); tcg_gen_ld_tl(tmp, cpu_env, offsetof(CPUNios2State, ctrl[CR_BSTATUS])); - gen_helper_eret(cpu_env, tmp, cpu_R[R_BA]); + gen_helper_eret(cpu_env, tmp, load_gpr(dc, R_BA)); tcg_temp_free(tmp); dc->base.is_jmp = DISAS_NORETURN; @@ -477,7 +469,6 @@ static void jmp(DisasContext *dc, uint32_t code, uint32_t flags) R_TYPE(instr, code); tcg_gen_mov_tl(cpu_pc, load_gpr(dc, instr.a)); - dc->base.is_jmp = DISAS_JUMP; } @@ -486,9 +477,7 @@ static void nextpc(DisasContext *dc, uint32_t code, uint32_t flags) { R_TYPE(instr, code); - if (likely(instr.c != R_ZERO)) { - tcg_gen_movi_tl(cpu_R[instr.c], dc->base.pc_next); - } + tcg_gen_movi_tl(dest_gpr(dc, instr.c), dc->base.pc_next); } /* @@ -500,7 +489,7 @@ static void callr(DisasContext *dc, uint32_t code, uint32_t flags) R_TYPE(instr, code); tcg_gen_mov_tl(cpu_pc, load_gpr(dc, instr.a)); - tcg_gen_movi_tl(cpu_R[R_RA], dc->base.pc_next); + tcg_gen_movi_tl(dest_gpr(dc, R_RA), dc->base.pc_next); dc->base.is_jmp = DISAS_JUMP; } @@ -516,15 +505,11 @@ static void rdctl(DisasContext *dc, uint32_t code, uint32_t flags) g_assert_not_reached(); #else R_TYPE(instr, code); - TCGv t1, t2; - - if (unlikely(instr.c == R_ZERO)) { - return; - } + TCGv t1, t2, dest = dest_gpr(dc, instr.c); /* Reserved registers read as zero. */ if (nios2_cr_reserved(&dc->cr_state[instr.imm5])) { - tcg_gen_movi_tl(cpu_R[instr.c], 0); + tcg_gen_movi_tl(dest, 0); return; } @@ -542,12 +527,12 @@ static void rdctl(DisasContext *dc, uint32_t code, uint32_t flags) t2 = tcg_temp_new(); tcg_gen_ld_tl(t1, cpu_env, offsetof(CPUNios2State, ctrl[CR_IPENDING])); tcg_gen_ld_tl(t2, cpu_env, offsetof(CPUNios2State, ctrl[CR_IENABLE])); - tcg_gen_and_tl(cpu_R[instr.c], t1, t2); + tcg_gen_and_tl(dest, t1, t2); tcg_temp_free(t1); tcg_temp_free(t2); break; default: - tcg_gen_ld_tl(cpu_R[instr.c], cpu_env, + tcg_gen_ld_tl(dest, cpu_env, offsetof(CPUNios2State, ctrl[instr.imm5])); break; } @@ -623,29 +608,21 @@ static void wrctl(DisasContext *dc, uint32_t code, uint32_t flags) static void gen_cmpxx(DisasContext *dc, uint32_t code, uint32_t flags) { R_TYPE(instr, code); - if (likely(instr.c != R_ZERO)) { - tcg_gen_setcond_tl(flags, cpu_R[instr.c], cpu_R[instr.a], - cpu_R[instr.b]); - } + tcg_gen_setcond_tl(flags, dest_gpr(dc, instr.c), + load_gpr(dc, instr.a), load_gpr(dc, instr.b)); } /* Math/logic instructions */ static void do_ri_math_logic(DisasContext *dc, uint32_t insn, GenFn2i *fn) { R_TYPE(instr, insn); - - if (likely(instr.c != R_ZERO)) { - fn(cpu_R[instr.c], load_gpr(dc, instr.a), instr.imm5); - } + fn(dest_gpr(dc, instr.c), load_gpr(dc, instr.a), instr.imm5); } static void do_rr_math_logic(DisasContext *dc, uint32_t insn, GenFn3 *fn) { R_TYPE(instr, insn); - - if (likely(instr.c != R_ZERO)) { - fn(cpu_R[instr.c], load_gpr(dc, instr.a), load_gpr(dc, instr.b)); - } + fn(dest_gpr(dc, instr.c), load_gpr(dc, instr.a), load_gpr(dc, instr.b)); } #define gen_ri_math_logic(fname, insn) \ @@ -673,13 +650,11 @@ gen_ri_math_logic(roli, rotli) static void do_rr_mul_high(DisasContext *dc, uint32_t insn, GenFn4 *fn) { R_TYPE(instr, insn); + TCGv discard = tcg_temp_new(); - if (likely(instr.c != R_ZERO)) { - TCGv discard = tcg_temp_new(); - fn(discard, cpu_R[instr.c], load_gpr(dc, instr.a), - load_gpr(dc, instr.b)); - tcg_temp_free(discard); - } + fn(discard, dest_gpr(dc, instr.c), + load_gpr(dc, instr.a), load_gpr(dc, instr.b)); + tcg_temp_free(discard); } #define gen_rr_mul_high(fname, insn) \ @@ -693,14 +668,11 @@ gen_rr_mul_high(mulxsu, mulsu2) static void do_rr_shift(DisasContext *dc, uint32_t insn, GenFn3 *fn) { R_TYPE(instr, insn); + TCGv sh = tcg_temp_new(); - if (likely(instr.c != R_ZERO)) { - TCGv sh = tcg_temp_new(); - - tcg_gen_andi_tl(sh, load_gpr(dc, instr.b), 31); - fn(cpu_R[instr.c], load_gpr(dc, instr.a), sh); - tcg_temp_free(sh); - } + tcg_gen_andi_tl(sh, load_gpr(dc, instr.b), 31); + fn(dest_gpr(dc, instr.c), load_gpr(dc, instr.a), sh); + tcg_temp_free(sh); } #define gen_rr_shift(fname, insn) \ @@ -716,39 +688,15 @@ gen_rr_shift(ror, rotr) static void divs(DisasContext *dc, uint32_t code, uint32_t flags) { R_TYPE(instr, (code)); - TCGv dest; - - if (instr.c == R_ZERO) { - dest = tcg_temp_new(); - } else { - dest = cpu_R[instr.c]; - } - - gen_helper_divs(dest, cpu_env, + gen_helper_divs(dest_gpr(dc, instr.c), cpu_env, load_gpr(dc, instr.a), load_gpr(dc, instr.b)); - - if (instr.c == R_ZERO) { - tcg_temp_free(dest); - } } static void divu(DisasContext *dc, uint32_t code, uint32_t flags) { R_TYPE(instr, (code)); - TCGv dest; - - if (instr.c == R_ZERO) { - dest = tcg_temp_new(); - } else { - dest = cpu_R[instr.c]; - } - - gen_helper_divu(dest, cpu_env, + gen_helper_divu(dest_gpr(dc, instr.c), cpu_env, load_gpr(dc, instr.a), load_gpr(dc, instr.b)); - - if (instr.c == R_ZERO) { - tcg_temp_free(dest); - } } static void trap(DisasContext *dc, uint32_t code, uint32_t flags) @@ -938,8 +886,14 @@ static void nios2_tr_translate_insn(DisasContextBase *dcbase, CPUState *cs) return; } + dc->sink = NULL; + instr = &i_type_instructions[op]; instr->handler(dc, code, instr->flags); + + if (dc->sink) { + tcg_temp_free(dc->sink); + } } static void nios2_tr_tb_stop(DisasContextBase *dcbase, CPUState *cs) -- 2.11.4.GIT