From: Richard Henderson Date: Fri, 4 Jul 2025 14:20:45 +0000 (-0600) Subject: target/arm: Implement SVE2p1 PEXT X-Git-Tag: v10.1.0-rc0~29^2~25 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=16fe3bb942e80ae0a2cd0690629bb73cc131092b;p=thirdparty%2Fqemu.git target/arm: Implement SVE2p1 PEXT Reviewed-by: Peter Maydell Signed-off-by: Richard Henderson Message-id: 20250704142112.1018902-83-richard.henderson@linaro.org Signed-off-by: Peter Maydell --- diff --git a/target/arm/tcg/helper-sve.h b/target/arm/tcg/helper-sve.h index 5f5ecc2e0de..ec82d0a4e74 100644 --- a/target/arm/tcg/helper-sve.h +++ b/target/arm/tcg/helper-sve.h @@ -2953,3 +2953,5 @@ DEF_HELPER_FLAGS_4(sve2p1_uminqv_b, TCG_CALL_NO_RWG, void, ptr, ptr, ptr, i32) DEF_HELPER_FLAGS_4(sve2p1_uminqv_h, TCG_CALL_NO_RWG, void, ptr, ptr, ptr, i32) DEF_HELPER_FLAGS_4(sve2p1_uminqv_s, TCG_CALL_NO_RWG, void, ptr, ptr, ptr, i32) DEF_HELPER_FLAGS_4(sve2p1_uminqv_d, TCG_CALL_NO_RWG, void, ptr, ptr, ptr, i32) + +DEF_HELPER_FLAGS_3(pext, TCG_CALL_NO_RWG, void, ptr, i32, i32) diff --git a/target/arm/tcg/sve.decode b/target/arm/tcg/sve.decode index a3221308ad4..b7622577594 100644 --- a/target/arm/tcg/sve.decode +++ b/target/arm/tcg/sve.decode @@ -60,6 +60,7 @@ %rn_ax2 6:4 !function=times_2 %pnd 0:3 !function=plus_8 +%pnn 5:3 !function=plus_8 ########################################################################### # Named attribute sets. These are used to make nice(er) names @@ -823,6 +824,11 @@ WHILE_lt_cnt4 00100101 .. 1 ..... 0110 . 1 ..... 1 . ... @while_cnt WHILE_gt_cnt2 00100101 .. 1 ..... 0100 . 0 ..... 1 . ... @while_cnt WHILE_gt_cnt4 00100101 .. 1 ..... 0110 . 0 ..... 1 . ... @while_cnt +# SVE2.1 extract mask predicate from predicate-as-counter +&pext rd rn esz imm +PEXT_1 00100101 esz:2 1 00000 0111 00 imm:2 ... 1 rd:4 &pext rn=%pnn +PEXT_2 00100101 esz:2 1 00000 0111 010 imm:1 ... 1 rd:4 &pext rn=%pnn + ### SVE Integer Wide Immediate - Unpredicated Group # SVE broadcast floating-point immediate (unpredicated) diff --git a/target/arm/tcg/sve_helper.c b/target/arm/tcg/sve_helper.c index 625734fff9a..866f85ba306 100644 --- a/target/arm/tcg/sve_helper.c +++ b/target/arm/tcg/sve_helper.c @@ -7821,3 +7821,31 @@ DO_FCVTLT(sve2_fcvtlt_sd, uint64_t, uint32_t, H1_8, H1_4, float32_to_float64) #undef DO_FCVTLT #undef DO_FCVTNT + +void HELPER(pext)(void *vd, uint32_t png, uint32_t desc) +{ + int pl = FIELD_EX32(desc, PREDDESC, OPRSZ); + int vl = pl * 8; + unsigned v_esz = FIELD_EX32(desc, PREDDESC, ESZ); + int part = FIELD_EX32(desc, PREDDESC, DATA); + DecodeCounter p = decode_counter(png, vl, v_esz); + uint64_t mask = pred_esz_masks[v_esz + p.lg2_stride]; + ARMPredicateReg *d = vd; + + /* + * Convert from element count to byte count and adjust + * for the portion of the 4*VL counter to be extracted. + */ + int b_count = (p.count << v_esz) - vl * part; + + memset(d, 0, sizeof(*d)); + if (p.invert) { + if (b_count <= 0) { + do_whilel(vd, mask, vl, vl); + } else if (b_count < vl) { + do_whileg(vd, mask, vl - b_count, vl); + } + } else if (b_count > 0) { + do_whilel(vd, mask, MIN(b_count, vl), vl); + } +} diff --git a/target/arm/tcg/translate-sve.c b/target/arm/tcg/translate-sve.c index 2e29dff9895..6ad4d1e289c 100644 --- a/target/arm/tcg/translate-sve.c +++ b/target/arm/tcg/translate-sve.c @@ -3336,6 +3336,42 @@ static bool trans_WHILE_ptr(DisasContext *s, arg_WHILE_ptr *a) return true; } +static bool do_pext(DisasContext *s, arg_pext *a, int n) +{ + TCGv_i32 t_png; + TCGv_ptr t_pd; + int pl; + + if (!sve_access_check(s)) { + return true; + } + + t_png = tcg_temp_new_i32(); + tcg_gen_ld16u_i32(t_png, tcg_env, + pred_full_reg_offset(s, a->rn) ^ + (HOST_BIG_ENDIAN ? 6 : 0)); + + t_pd = tcg_temp_new_ptr(); + pl = pred_full_reg_size(s); + + for (int i = 0; i < n; ++i) { + int rd = (a->rd + i) % 16; + int part = a->imm * n + i; + unsigned desc = 0; + + desc = FIELD_DP32(desc, PREDDESC, OPRSZ, pl); + desc = FIELD_DP32(desc, PREDDESC, ESZ, a->esz); + desc = FIELD_DP32(desc, PREDDESC, DATA, part); + + tcg_gen_addi_ptr(t_pd, tcg_env, pred_full_reg_offset(s, rd)); + gen_helper_pext(t_pd, t_png, tcg_constant_i32(desc)); + } + return true; +} + +TRANS_FEAT(PEXT_1, aa64_sme2_or_sve2p1, do_pext, a, 1) +TRANS_FEAT(PEXT_2, aa64_sme2_or_sve2p1, do_pext, a, 2) + /* *** SVE Integer Wide Immediate - Unpredicated Group */ diff --git a/target/arm/tcg/vec_internal.h b/target/arm/tcg/vec_internal.h index 5efd257c50d..61c67bb35e7 100644 --- a/target/arm/tcg/vec_internal.h +++ b/target/arm/tcg/vec_internal.h @@ -337,4 +337,78 @@ bfloat16 helper_sme2_ah_fmin_b16(bfloat16 a, bfloat16 b, float_status *fpst); float32 sve_f16_to_f32(float16 f, float_status *fpst); float16 sve_f32_to_f16(float32 f, float_status *fpst); +/* + * Decode helper functions for predicate as counter. + */ + +typedef struct { + unsigned count; + unsigned lg2_stride; + bool invert; +} DecodeCounter; + +static inline DecodeCounter +decode_counter(unsigned png, unsigned vl, unsigned v_esz) +{ + DecodeCounter ret = { }; + + /* C.f. Arm pseudocode CounterToPredicate. */ + if (likely(png & 0xf)) { + unsigned p_esz = ctz32(png); + + /* + * maxbit = log2(pl(bits) * 4) + * = log2(vl(bytes) * 4) + * = log2(vl) + 2 + * maxbit_mask = ones + * = (1 << (maxbit + 1)) - 1 + * = (1 << (log2(vl) + 2 + 1)) - 1 + * = (1 << (log2(vl) + 3)) - 1 + * = (pow2ceil(vl) << 3) - 1 + */ + ret.count = png & (((unsigned)pow2ceil(vl) << 3) - 1); + ret.count >>= p_esz + 1; + + ret.invert = (png >> 15) & 1; + + /* + * The Arm pseudocode for CounterToPredicate expands the count to + * a set of bits, and then the operation proceeds as for the original + * interpretation of predicates as a set of bits. + * + * We can avoid the expansion by adjusting the count and supplying + * an element stride. + */ + if (unlikely(p_esz != v_esz)) { + if (p_esz < v_esz) { + /* + * For predicate esz < vector esz, the expanded predicate + * will have more bits set than will be consumed. + * Adjust the count down, rounding up. + * Consider p_esz = MO_8, v_esz = MO_64, count 14: + * The expanded predicate would be + * 0011 1111 1111 1111 + * The significant bits are + * ...1 ...1 ...1 ...1 + */ + unsigned shift = v_esz - p_esz; + unsigned trunc = ret.count >> shift; + ret.count = trunc + (ret.count != (trunc << shift)); + } else { + /* + * For predicate esz > vector esz, the expanded predicate + * will have bits set only at power-of-two multiples of + * the vector esz. Bits at other multiples will all be + * false. Adjust the count up, and supply the caller + * with a stride of elements to skip. + */ + unsigned shift = p_esz - v_esz; + ret.count <<= shift; + ret.lg2_stride = shift; + } + } + } + return ret; +} + #endif /* TARGET_ARM_VEC_INTERNAL_H */