From baa552e54f1612e85ca76149eca328dd268a4695 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Tue, 15 May 2018 14:58:43 +0100 Subject: [PATCH] target/arm: Implement FCVT (scalar, integer) for fp16 MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Cc: qemu-stable@nongnu.org Reviewed-by: Alex Bennée Signed-off-by: Richard Henderson Tested-by: Alex Bennée Message-id: 20180512003217.9105-4-richard.henderson@linaro.org Signed-off-by: Peter Maydell (cherry picked from commit 564a0632504fad840491aa9a59453f4e64a316c4) Signed-off-by: Michael Roth --- target/arm/helper.c | 38 ++++++++++++++- target/arm/helper.h | 6 +++ target/arm/translate-a64.c | 96 +++++++++++++++++++++++++++++++------- 3 files changed, 122 insertions(+), 18 deletions(-) diff --git a/target/arm/helper.c b/target/arm/helper.c index c07c1d7f48..1043d6ed32 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -11416,8 +11416,12 @@ VFP_CONV_FIX_A64(uq, s, 32, 64, uint64) #undef VFP_CONV_FIX_A64 /* Conversion to/from f16 can overflow to infinity before/after scaling. - * Therefore we convert to f64 (which does not round), scale, - * and then convert f64 to f16 (which may round). + * Therefore we convert to f64, scale, and then convert f64 to f16; or + * vice versa for conversion to integer. + * + * For 16- and 32-bit integers, the conversion to f64 never rounds. + * For 64-bit integers, any integer that would cause rounding will also + * overflow to f16 infinity, so there is no double rounding problem. */ static float16 do_postscale_fp16(float64 f, int shift, float_status *fpst) @@ -11435,6 +11439,16 @@ float16 HELPER(vfp_ultoh)(uint32_t x, uint32_t shift, void *fpst) return do_postscale_fp16(uint32_to_float64(x, fpst), shift, fpst); } +float16 HELPER(vfp_sqtoh)(uint64_t x, uint32_t shift, void *fpst) +{ + return do_postscale_fp16(int64_to_float64(x, fpst), shift, fpst); +} + +float16 HELPER(vfp_uqtoh)(uint64_t x, uint32_t shift, void *fpst) +{ + return do_postscale_fp16(uint64_to_float64(x, fpst), shift, fpst); +} + static float64 do_prescale_fp16(float16 f, int shift, float_status *fpst) { if (unlikely(float16_is_any_nan(f))) { @@ -11464,6 +11478,26 @@ uint32_t HELPER(vfp_touhh)(float16 x, uint32_t shift, void *fpst) return float64_to_uint16(do_prescale_fp16(x, shift, fpst), fpst); } +uint32_t HELPER(vfp_toslh)(float16 x, uint32_t shift, void *fpst) +{ + return float64_to_int32(do_prescale_fp16(x, shift, fpst), fpst); +} + +uint32_t HELPER(vfp_toulh)(float16 x, uint32_t shift, void *fpst) +{ + return float64_to_uint32(do_prescale_fp16(x, shift, fpst), fpst); +} + +uint64_t HELPER(vfp_tosqh)(float16 x, uint32_t shift, void *fpst) +{ + return float64_to_int64(do_prescale_fp16(x, shift, fpst), fpst); +} + +uint64_t HELPER(vfp_touqh)(float16 x, uint32_t shift, void *fpst) +{ + return float64_to_uint64(do_prescale_fp16(x, shift, fpst), fpst); +} + /* Set the current fp rounding mode and return the old one. * The argument is a softfloat float_round_ value. */ diff --git a/target/arm/helper.h b/target/arm/helper.h index 1969b37f2d..ce89968b2d 100644 --- a/target/arm/helper.h +++ b/target/arm/helper.h @@ -151,6 +151,10 @@ DEF_HELPER_3(vfp_touhd_round_to_zero, i64, f64, i32, ptr) DEF_HELPER_3(vfp_tould_round_to_zero, i64, f64, i32, ptr) DEF_HELPER_3(vfp_touhh, i32, f16, i32, ptr) DEF_HELPER_3(vfp_toshh, i32, f16, i32, ptr) +DEF_HELPER_3(vfp_toulh, i32, f16, i32, ptr) +DEF_HELPER_3(vfp_toslh, i32, f16, i32, ptr) +DEF_HELPER_3(vfp_touqh, i64, f16, i32, ptr) +DEF_HELPER_3(vfp_tosqh, i64, f16, i32, ptr) DEF_HELPER_3(vfp_toshs, i32, f32, i32, ptr) DEF_HELPER_3(vfp_tosls, i32, f32, i32, ptr) DEF_HELPER_3(vfp_tosqs, i64, f32, i32, ptr) @@ -177,6 +181,8 @@ DEF_HELPER_3(vfp_ultod, f64, i64, i32, ptr) DEF_HELPER_3(vfp_uqtod, f64, i64, i32, ptr) DEF_HELPER_3(vfp_sltoh, f16, i32, i32, ptr) DEF_HELPER_3(vfp_ultoh, f16, i32, i32, ptr) +DEF_HELPER_3(vfp_sqtoh, f16, i64, i32, ptr) +DEF_HELPER_3(vfp_uqtoh, f16, i64, i32, ptr) DEF_HELPER_FLAGS_2(set_rmode, TCG_CALL_NO_RWG, i32, i32, ptr) DEF_HELPER_FLAGS_2(set_neon_rmode, TCG_CALL_NO_RWG, i32, i32, env) diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c index b05f9bfe91..33be611bdb 100644 --- a/target/arm/translate-a64.c +++ b/target/arm/translate-a64.c @@ -5268,11 +5268,11 @@ 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; + TCGv_i32 tcg_shift, tcg_single; + TCGv_i64 tcg_double; - tcg_fpstatus = get_fpstatus_ptr(false); + tcg_fpstatus = get_fpstatus_ptr(type == 3); tcg_shift = tcg_const_i32(64 - scale); @@ -5290,8 +5290,9 @@ static void handle_fpfpcvt(DisasContext *s, int rd, int rn, int opcode, tcg_int = tcg_extend; } - if (is_double) { - TCGv_i64 tcg_double = tcg_temp_new_i64(); + switch (type) { + case 1: /* float64 */ + tcg_double = tcg_temp_new_i64(); if (is_signed) { gen_helper_vfp_sqtod(tcg_double, tcg_int, tcg_shift, tcg_fpstatus); @@ -5301,8 +5302,10 @@ static void handle_fpfpcvt(DisasContext *s, int rd, int rn, int opcode, } write_fp_dreg(s, rd, tcg_double); tcg_temp_free_i64(tcg_double); - } else { - TCGv_i32 tcg_single = tcg_temp_new_i32(); + break; + + case 0: /* float32 */ + tcg_single = tcg_temp_new_i32(); if (is_signed) { gen_helper_vfp_sqtos(tcg_single, tcg_int, tcg_shift, tcg_fpstatus); @@ -5312,6 +5315,23 @@ static void handle_fpfpcvt(DisasContext *s, int rd, int rn, int opcode, } write_fp_sreg(s, rd, tcg_single); tcg_temp_free_i32(tcg_single); + break; + + case 3: /* float16 */ + tcg_single = tcg_temp_new_i32(); + if (is_signed) { + gen_helper_vfp_sqtoh(tcg_single, tcg_int, + tcg_shift, tcg_fpstatus); + } else { + gen_helper_vfp_uqtoh(tcg_single, tcg_int, + tcg_shift, tcg_fpstatus); + } + write_fp_sreg(s, rd, tcg_single); + tcg_temp_free_i32(tcg_single); + break; + + default: + g_assert_not_reached(); } } else { TCGv_i64 tcg_int = cpu_reg(s, rd); @@ -5328,8 +5348,9 @@ static void handle_fpfpcvt(DisasContext *s, int rd, int rn, int opcode, gen_helper_set_rmode(tcg_rmode, tcg_rmode, tcg_fpstatus); - if (is_double) { - TCGv_i64 tcg_double = read_fp_dreg(s, rn); + switch (type) { + case 1: /* float64 */ + tcg_double = read_fp_dreg(s, rn); if (is_signed) { if (!sf) { gen_helper_vfp_tosld(tcg_int, tcg_double, @@ -5347,9 +5368,14 @@ static void handle_fpfpcvt(DisasContext *s, int rd, int rn, int opcode, tcg_shift, tcg_fpstatus); } } + if (!sf) { + tcg_gen_ext32u_i64(tcg_int, tcg_int); + } tcg_temp_free_i64(tcg_double); - } else { - TCGv_i32 tcg_single = read_fp_sreg(s, rn); + break; + + case 0: /* float32 */ + tcg_single = read_fp_sreg(s, rn); if (sf) { if (is_signed) { gen_helper_vfp_tosqs(tcg_int, tcg_single, @@ -5371,14 +5397,39 @@ static void handle_fpfpcvt(DisasContext *s, int rd, int rn, int opcode, tcg_temp_free_i32(tcg_dest); } tcg_temp_free_i32(tcg_single); + break; + + case 3: /* float16 */ + tcg_single = read_fp_sreg(s, rn); + if (sf) { + if (is_signed) { + gen_helper_vfp_tosqh(tcg_int, tcg_single, + tcg_shift, tcg_fpstatus); + } else { + gen_helper_vfp_touqh(tcg_int, tcg_single, + tcg_shift, tcg_fpstatus); + } + } else { + TCGv_i32 tcg_dest = tcg_temp_new_i32(); + if (is_signed) { + gen_helper_vfp_toslh(tcg_dest, tcg_single, + tcg_shift, tcg_fpstatus); + } else { + gen_helper_vfp_toulh(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); + break; + + default: + g_assert_not_reached(); } gen_helper_set_rmode(tcg_rmode, tcg_rmode, tcg_fpstatus); tcg_temp_free_i32(tcg_rmode); - - if (!sf) { - tcg_gen_ext32u_i64(tcg_int, tcg_int); - } } tcg_temp_free_ptr(tcg_fpstatus); @@ -5548,7 +5599,20 @@ static void disas_fp_int_conv(DisasContext *s, uint32_t insn) /* actual FP conversions */ bool itof = extract32(opcode, 1, 1); - if (type > 1 || (rmode != 0 && opcode > 1)) { + if (rmode != 0 && opcode > 1) { + unallocated_encoding(s); + return; + } + switch (type) { + case 0: /* float32 */ + case 1: /* float64 */ + break; + case 3: /* float16 */ + if (arm_dc_feature(s, ARM_FEATURE_V8_FP16)) { + break; + } + /* fallthru */ + default: unallocated_encoding(s); return; } -- 2.39.2