From 8f0c6758b0e1c3b9676e7c3ccea8a176537cf843 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Alex=20Benn=C3=A9e?= Date: Mon, 17 Mar 2014 16:31:50 +0000 Subject: [PATCH] target-arm: A64: Add FRECPX (reciprocal exponent) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit These are fairly simple exponent only estimation functions using helpers. Signed-off-by: Alex Bennée Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 1394822294-14837-14-git-send-email-peter.maydell@linaro.org --- target-arm/helper-a64.c | 59 ++++++++++++++++++++++++++++++++ target-arm/helper-a64.h | 2 ++ target-arm/translate-a64.c | 70 +++++++++++++++++++++++++++++++++++++- 3 files changed, 130 insertions(+), 1 deletion(-) diff --git a/target-arm/helper-a64.c b/target-arm/helper-a64.c index c31c45e729..cea2468b30 100644 --- a/target-arm/helper-a64.c +++ b/target-arm/helper-a64.c @@ -354,3 +354,62 @@ uint64_t HELPER(neon_addlp_u16)(uint64_t a) tmp += (a >> 16) & 0x0000ffff0000ffffULL; return tmp; } + +/* Floating-point reciprocal exponent - see FPRecpX in ARM ARM */ +float32 HELPER(frecpx_f32)(float32 a, void *fpstp) +{ + float_status *fpst = fpstp; + uint32_t val32, sbit; + int32_t exp; + + if (float32_is_any_nan(a)) { + float32 nan = a; + if (float32_is_signaling_nan(a)) { + float_raise(float_flag_invalid, fpst); + nan = float32_maybe_silence_nan(a); + } + if (fpst->default_nan_mode) { + nan = float32_default_nan; + } + return nan; + } + + val32 = float32_val(a); + sbit = 0x80000000ULL & val32; + exp = extract32(val32, 23, 8); + + if (exp == 0) { + return make_float32(sbit | (0xfe << 23)); + } else { + return make_float32(sbit | (~exp & 0xff) << 23); + } +} + +float64 HELPER(frecpx_f64)(float64 a, void *fpstp) +{ + float_status *fpst = fpstp; + uint64_t val64, sbit; + int64_t exp; + + if (float64_is_any_nan(a)) { + float64 nan = a; + if (float64_is_signaling_nan(a)) { + float_raise(float_flag_invalid, fpst); + nan = float64_maybe_silence_nan(a); + } + if (fpst->default_nan_mode) { + nan = float64_default_nan; + } + return nan; + } + + val64 = float64_val(a); + sbit = 0x8000000000000000ULL & val64; + exp = extract64(float64_val(a), 52, 11); + + if (exp == 0) { + return make_float64(sbit | (0x7feULL << 52)); + } else { + return make_float64(sbit | (~exp & 0x7ffULL) << 52); + } +} diff --git a/target-arm/helper-a64.h b/target-arm/helper-a64.h index 88fc9fe9e7..8cbc3492d4 100644 --- a/target-arm/helper-a64.h +++ b/target-arm/helper-a64.h @@ -43,3 +43,5 @@ DEF_HELPER_FLAGS_1(neon_addlp_s8, TCG_CALL_NO_RWG_SE, i64, i64) DEF_HELPER_FLAGS_1(neon_addlp_u8, TCG_CALL_NO_RWG_SE, i64, i64) DEF_HELPER_FLAGS_1(neon_addlp_s16, TCG_CALL_NO_RWG_SE, i64, i64) DEF_HELPER_FLAGS_1(neon_addlp_u16, TCG_CALL_NO_RWG_SE, i64, i64) +DEF_HELPER_FLAGS_2(frecpx_f64, TCG_CALL_NO_RWG, f64, f64, ptr) +DEF_HELPER_FLAGS_2(frecpx_f32, TCG_CALL_NO_RWG, f32, f32, ptr) diff --git a/target-arm/translate-a64.c b/target-arm/translate-a64.c index 2b1ca64b19..86e5d3e1db 100644 --- a/target-arm/translate-a64.c +++ b/target-arm/translate-a64.c @@ -6886,6 +6886,72 @@ static void handle_2misc_fcmp_zero(DisasContext *s, int opcode, tcg_temp_free_ptr(fpst); } +static void handle_2misc_reciprocal(DisasContext *s, int opcode, + bool is_scalar, bool is_u, bool is_q, + int size, int rn, int rd) +{ + bool is_double = (size == 3); + TCGv_ptr fpst = get_fpstatus_ptr(); + + if (is_double) { + TCGv_i64 tcg_op = tcg_temp_new_i64(); + TCGv_i64 tcg_res = tcg_temp_new_i64(); + int pass; + + for (pass = 0; pass < (is_scalar ? 1 : 2); pass++) { + read_vec_element(s, tcg_op, rn, pass, MO_64); + switch (opcode) { + case 0x3f: /* FRECPX */ + gen_helper_frecpx_f64(tcg_res, tcg_op, fpst); + break; + default: + g_assert_not_reached(); + } + write_vec_element(s, tcg_res, rd, pass, MO_64); + } + if (is_scalar) { + clear_vec_high(s, rd); + } + + tcg_temp_free_i64(tcg_res); + tcg_temp_free_i64(tcg_op); + } else { + TCGv_i32 tcg_op = tcg_temp_new_i32(); + TCGv_i32 tcg_res = tcg_temp_new_i32(); + int pass, maxpasses; + + if (is_scalar) { + maxpasses = 1; + } else { + maxpasses = is_q ? 4 : 2; + } + + for (pass = 0; pass < maxpasses; pass++) { + read_vec_element_i32(s, tcg_op, rn, pass, MO_32); + + switch (opcode) { + case 0x3f: /* FRECPX */ + gen_helper_frecpx_f32(tcg_res, tcg_op, fpst); + break; + default: + g_assert_not_reached(); + } + + if (is_scalar) { + write_fp_sreg(s, rd, tcg_res); + } else { + write_vec_element_i32(s, tcg_res, rd, pass, MO_32); + } + } + tcg_temp_free_i32(tcg_res); + tcg_temp_free_i32(tcg_op); + if (!is_q && !is_scalar) { + clear_vec_high(s, rd); + } + } + tcg_temp_free_ptr(fpst); +} + /* C3.6.12 AdvSIMD scalar two reg misc * 31 30 29 28 24 23 22 21 17 16 12 11 10 9 5 4 0 * +-----+---+-----------+------+-----------+--------+-----+------+------+ @@ -6942,6 +7008,9 @@ static void disas_simd_scalar_two_reg_misc(DisasContext *s, uint32_t insn) handle_simd_intfp_conv(s, rd, rn, 1, is_signed, 0, size); return; } + case 0x3f: /* FRECPX */ + handle_2misc_reciprocal(s, opcode, true, u, true, size, rn, rd); + return; case 0x1a: /* FCVTNS */ case 0x1b: /* FCVTMS */ case 0x3a: /* FCVTPS */ @@ -6960,7 +7029,6 @@ static void disas_simd_scalar_two_reg_misc(DisasContext *s, uint32_t insn) rmode = FPROUNDING_TIEAWAY; break; case 0x3d: /* FRECPE */ - case 0x3f: /* FRECPX */ case 0x56: /* FCVTXN, FCVTXN2 */ case 0x7d: /* FRSQRTE */ unsupported_encoding(s, insn);