From 9c1d83337479c770deea547643f9a7f1a8470fb9 Mon Sep 17 00:00:00 2001 From: Alexander Graf Date: Tue, 3 Dec 2013 11:21:08 +0000 Subject: target-arm: A64: Add "Floating-point<->fixed-point" instructions This patch adds emulation for the instruction group labeled "Floating-point <-> fixed-point conversions" in the ARM ARM. Namely this includes the instructions SCVTF, UCVTF, FCVTZS, FCVTZU (scalar, fixed-point). Signed-off-by: Alexander Graf [WN: Commit message tweak, rebased, updated to new infrastructure. Applied bug fixes from Michael Matz and Janne Grunau.] Signed-off-by: Will Newton [PMM: significant cleanup] Signed-off-by: Peter Maydell --- target-arm/helper.c | 13 ++++ target-arm/helper.h | 2 + target-arm/translate-a64.c | 186 ++++++++++++++++++++++++++++++++++++++++++++- 3 files changed, 200 insertions(+), 1 deletion(-) diff --git a/target-arm/helper.c b/target-arm/helper.c index 7736d4bdee..5b5f24e790 100644 --- a/target-arm/helper.c +++ b/target-arm/helper.c @@ -4043,6 +4043,19 @@ VFP_CONV_FIX_A64(uq, s, 32, 64, uint64) #undef VFP_CONV_FIX_FLOAT #undef VFP_CONV_FLOAT_FIX_ROUND +/* Set the current fp rounding mode and return the old one. + * The argument is a softfloat float_round_ value. + */ +uint32_t HELPER(set_rmode)(uint32_t rmode, CPUARMState *env) +{ + float_status *fp_status = &env->vfp.fp_status; + + uint32_t prev_rmode = get_float_rounding_mode(fp_status); + set_float_rounding_mode(rmode, fp_status); + + return prev_rmode; +} + /* Half precision conversions. */ static float32 do_fcvt_f16_to_f32(uint32_t a, CPUARMState *env, float_status *s) { diff --git a/target-arm/helper.h b/target-arm/helper.h index 2e1af4671c..25b6b4f493 100644 --- a/target-arm/helper.h +++ b/target-arm/helper.h @@ -148,6 +148,8 @@ DEF_HELPER_3(vfp_uhtod, f64, i64, i32, ptr) DEF_HELPER_3(vfp_ultod, f64, i64, i32, ptr) DEF_HELPER_3(vfp_uqtod, f64, i64, i32, ptr) +DEF_HELPER_FLAGS_2(set_rmode, TCG_CALL_NO_RWG, i32, i32, env) + DEF_HELPER_2(vfp_fcvt_f16_to_f32, f32, i32, env) DEF_HELPER_2(vfp_fcvt_f32_to_f16, i32, f32, env) DEF_HELPER_2(neon_fcvt_f16_to_f32, f32, i32, env) diff --git a/target-arm/translate-a64.c b/target-arm/translate-a64.c index c9fbf0f0f7..ec8abc708a 100644 --- a/target-arm/translate-a64.c +++ b/target-arm/translate-a64.c @@ -3186,6 +3186,34 @@ static void disas_data_proc_reg(DisasContext *s, uint32_t insn) } } +/* Convert ARM rounding mode to softfloat */ +static inline int arm_rmode_to_sf(int rmode) +{ + switch (rmode) { + case FPROUNDING_TIEAWAY: + rmode = float_round_ties_away; + break; + case FPROUNDING_ODD: + /* FIXME: add support for TIEAWAY and ODD */ + qemu_log_mask(LOG_UNIMP, "arm: unimplemented rounding mode: %d\n", + rmode); + case FPROUNDING_TIEEVEN: + default: + rmode = float_round_nearest_even; + break; + case FPROUNDING_POSINF: + rmode = float_round_up; + break; + case FPROUNDING_NEGINF: + rmode = float_round_down; + break; + case FPROUNDING_ZERO: + rmode = float_round_to_zero; + break; + } + return rmode; +} + static void handle_fp_compare(DisasContext *s, bool is_double, unsigned int rn, unsigned int rm, bool cmp_with_zero, bool signal_all_nans) @@ -3651,6 +3679,132 @@ static void disas_fp_imm(DisasContext *s, uint32_t insn) tcg_temp_free_i64(tcg_res); } +/* Handle floating point <=> fixed point conversions. Note that we can + * also deal with fp <=> integer conversions as a special case (scale == 64) + * OPTME: consider handling that special case specially or at least skipping + * the call to scalbn in the helpers for zero shifts. + */ +static void handle_fpfpcvt(DisasContext *s, int rd, int rn, int opcode, + bool itof, int rmode, int scale, int sf, int type) +{ + bool is_signed = !(opcode & 1); + bool is_double = type; + TCGv_ptr tcg_fpstatus; + TCGv_i32 tcg_shift; + + tcg_fpstatus = get_fpstatus_ptr(); + + tcg_shift = tcg_const_i32(64 - scale); + + if (itof) { + TCGv_i64 tcg_int = cpu_reg(s, rn); + if (!sf) { + TCGv_i64 tcg_extend = new_tmp_a64(s); + + if (is_signed) { + tcg_gen_ext32s_i64(tcg_extend, tcg_int); + } else { + tcg_gen_ext32u_i64(tcg_extend, tcg_int); + } + + tcg_int = tcg_extend; + } + + if (is_double) { + TCGv_i64 tcg_double = tcg_temp_new_i64(); + if (is_signed) { + gen_helper_vfp_sqtod(tcg_double, tcg_int, + tcg_shift, tcg_fpstatus); + } else { + gen_helper_vfp_uqtod(tcg_double, tcg_int, + tcg_shift, tcg_fpstatus); + } + write_fp_dreg(s, rd, tcg_double); + tcg_temp_free_i64(tcg_double); + } else { + TCGv_i32 tcg_single = tcg_temp_new_i32(); + if (is_signed) { + gen_helper_vfp_sqtos(tcg_single, tcg_int, + tcg_shift, tcg_fpstatus); + } else { + gen_helper_vfp_uqtos(tcg_single, tcg_int, + tcg_shift, tcg_fpstatus); + } + write_fp_sreg(s, rd, tcg_single); + tcg_temp_free_i32(tcg_single); + } + } else { + TCGv_i64 tcg_int = cpu_reg(s, rd); + TCGv_i32 tcg_rmode; + + if (extract32(opcode, 2, 1)) { + /* There are too many rounding modes to all fit into rmode, + * so FCVTA[US] is a special case. + */ + rmode = FPROUNDING_TIEAWAY; + } + + tcg_rmode = tcg_const_i32(arm_rmode_to_sf(rmode)); + + gen_helper_set_rmode(tcg_rmode, tcg_rmode, cpu_env); + + if (is_double) { + TCGv_i64 tcg_double = read_fp_dreg(s, rn); + if (is_signed) { + if (!sf) { + gen_helper_vfp_tosld(tcg_int, tcg_double, + tcg_shift, tcg_fpstatus); + } else { + gen_helper_vfp_tosqd(tcg_int, tcg_double, + tcg_shift, tcg_fpstatus); + } + } else { + if (!sf) { + gen_helper_vfp_tould(tcg_int, tcg_double, + tcg_shift, tcg_fpstatus); + } else { + gen_helper_vfp_touqd(tcg_int, tcg_double, + tcg_shift, tcg_fpstatus); + } + } + tcg_temp_free_i64(tcg_double); + } else { + TCGv_i32 tcg_single = read_fp_sreg(s, rn); + if (sf) { + if (is_signed) { + gen_helper_vfp_tosqs(tcg_int, tcg_single, + tcg_shift, tcg_fpstatus); + } else { + gen_helper_vfp_touqs(tcg_int, tcg_single, + tcg_shift, tcg_fpstatus); + } + } else { + TCGv_i32 tcg_dest = tcg_temp_new_i32(); + if (is_signed) { + gen_helper_vfp_tosls(tcg_dest, tcg_single, + tcg_shift, tcg_fpstatus); + } else { + gen_helper_vfp_touls(tcg_dest, tcg_single, + tcg_shift, tcg_fpstatus); + } + tcg_gen_extu_i32_i64(tcg_int, tcg_dest); + tcg_temp_free_i32(tcg_dest); + } + tcg_temp_free_i32(tcg_single); + } + + gen_helper_set_rmode(tcg_rmode, tcg_rmode, cpu_env); + tcg_temp_free_i32(tcg_rmode); + + if (!sf) { + tcg_gen_ext32u_i64(tcg_int, tcg_int); + } + } + + tcg_temp_free_ptr(tcg_fpstatus); + tcg_temp_free_i32(tcg_shift); +} + /* C3.6.29 Floating point <-> fixed point conversions * 31 30 29 28 24 23 22 21 20 19 18 16 15 10 9 5 4 0 * +----+---+---+-----------+------+---+-------+--------+-------+------+------+ @@ -3659,7 +3813,37 @@ static void disas_fp_imm(DisasContext *s, uint32_t insn) */ static void disas_fp_fixed_conv(DisasContext *s, uint32_t insn) { - unsupported_encoding(s, insn); + int rd = extract32(insn, 0, 5); + int rn = extract32(insn, 5, 5); + int scale = extract32(insn, 10, 6); + int opcode = extract32(insn, 16, 3); + int rmode = extract32(insn, 19, 2); + int type = extract32(insn, 22, 2); + bool sbit = extract32(insn, 29, 1); + bool sf = extract32(insn, 31, 1); + bool itof; + + if (sbit || (type > 1) + || (!sf && scale < 32)) { + unallocated_encoding(s); + return; + } + + switch ((rmode << 3) | opcode) { + case 0x2: /* SCVTF */ + case 0x3: /* UCVTF */ + itof = true; + break; + case 0x18: /* FCVTZS */ + case 0x19: /* FCVTZU */ + itof = false; + break; + default: + unallocated_encoding(s); + return; + } + + handle_fpfpcvt(s, rd, rn, opcode, itof, FPROUNDING_ZERO, scale, sf, type); } static void handle_fmov(DisasContext *s, int rd, int rn, int type, bool itof) -- cgit v1.2.3