{"id":2227685,"url":"http://patchwork.ozlabs.org/api/1.1/patches/2227685/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20260424043014.46305-34-richard.henderson@linaro.org/","project":{"id":14,"url":"http://patchwork.ozlabs.org/api/1.1/projects/14/?format=json","name":"QEMU Development","link_name":"qemu-devel","list_id":"qemu-devel.nongnu.org","list_email":"qemu-devel@nongnu.org","web_url":"","scm_url":"","webscm_url":""},"msgid":"<20260424043014.46305-34-richard.henderson@linaro.org>","date":"2026-04-24T04:30:07","name":"[v2,33/40] target/arm: Implement FCVTN (16- to 8-bit fp) for SVE","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"72b95151f9550d421f1e44b7a727430253121b78","submitter":{"id":72104,"url":"http://patchwork.ozlabs.org/api/1.1/people/72104/?format=json","name":"Richard Henderson","email":"richard.henderson@linaro.org"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20260424043014.46305-34-richard.henderson@linaro.org/mbox/","series":[{"id":501300,"url":"http://patchwork.ozlabs.org/api/1.1/series/501300/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/list/?series=501300","date":"2026-04-24T04:29:37","name":"target/arm: Implement FEAT_FP8","version":2,"mbox":"http://patchwork.ozlabs.org/series/501300/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/2227685/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2227685/checks/","tags":{},"headers":{"Return-Path":"<qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org>","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=linaro.org header.i=@linaro.org header.a=rsa-sha256\n header.s=google header.b=UprfmIgI;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org\n (client-ip=209.51.188.17; helo=lists1p.gnu.org;\n envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org;\n receiver=patchwork.ozlabs.org)"],"Received":["from lists1p.gnu.org (lists1p.gnu.org [209.51.188.17])\n\t(using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits))\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4g20Vq2HT8z1yDD\n\tfor <incoming@patchwork.ozlabs.org>; Fri, 24 Apr 2026 14:34:59 +1000 (AEST)","from localhost ([::1] helo=lists1p.gnu.org)\n\tby lists1p.gnu.org with esmtp (Exim 4.90_1)\n\t(envelope-from <qemu-devel-bounces@nongnu.org>)\n\tid 1wG8DY-0002uz-E8; Fri, 24 Apr 2026 00:32:40 -0400","from eggs.gnu.org ([2001:470:142:3::10])\n by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256)\n (Exim 4.90_1) (envelope-from <richard.henderson@linaro.org>)\n id 1wG8DU-0002kt-Ch\n for qemu-devel@nongnu.org; Fri, 24 Apr 2026 00:32:36 -0400","from mail-oa1-x2d.google.com ([2001:4860:4864:20::2d])\n by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128)\n (Exim 4.90_1) (envelope-from <richard.henderson@linaro.org>)\n id 1wG8DS-0003bZ-Dn\n for qemu-devel@nongnu.org; Fri, 24 Apr 2026 00:32:36 -0400","by mail-oa1-x2d.google.com with SMTP id\n 586e51a60fabf-40ede943bf0so4724341fac.2\n for <qemu-devel@nongnu.org>; Thu, 23 Apr 2026 21:32:34 -0700 (PDT)","from stoup.. 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helo=mail-oa1-x2d.google.com","X-Spam_score_int":"-20","X-Spam_score":"-2.1","X-Spam_bar":"--","X-Spam_report":"(-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1,\n DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1,\n RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001,\n SPF_PASS=-0.001 autolearn=ham autolearn_force=no","X-Spam_action":"no action","X-BeenThere":"qemu-devel@nongnu.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"qemu development <qemu-devel.nongnu.org>","List-Unsubscribe":"<https://lists.nongnu.org/mailman/options/qemu-devel>,\n <mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>","List-Archive":"<https://lists.nongnu.org/archive/html/qemu-devel>","List-Post":"<mailto:qemu-devel@nongnu.org>","List-Help":"<mailto:qemu-devel-request@nongnu.org?subject=help>","List-Subscribe":"<https://lists.nongnu.org/mailman/listinfo/qemu-devel>,\n <mailto:qemu-devel-request@nongnu.org?subject=subscribe>","Errors-To":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org","Sender":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org"},"content":"Signed-off-by: Richard Henderson <richard.henderson@linaro.org>\n---\n target/arm/tcg/helper-fp8-defs.h |  1 +\n target/arm/tcg/fp8_helper.c      | 40 ++++++++++++++++++++++++++++++++\n target/arm/tcg/translate-sve.c   |  2 ++\n target/arm/tcg/sve.decode        |  1 +\n 4 files changed, 44 insertions(+)","diff":"diff --git a/target/arm/tcg/helper-fp8-defs.h b/target/arm/tcg/helper-fp8-defs.h\nindex 023a49e12f..e67fb191c2 100644\n--- a/target/arm/tcg/helper-fp8-defs.h\n+++ b/target/arm/tcg/helper-fp8-defs.h\n@@ -16,5 +16,6 @@ DEF_HELPER_FLAGS_4(sme2_fcvtl_hb, TCG_CALL_NO_RWG, void, ptr, ptr, env, i32)\n DEF_HELPER_FLAGS_4(sve2_bfcvtn_bh, TCG_CALL_NO_RWG, void, ptr, ptr, env, i32)\n \n DEF_HELPER_FLAGS_5(gvec_fcvt_bh, TCG_CALL_NO_RWG, void, ptr, ptr, ptr, env, i32)\n+DEF_HELPER_FLAGS_4(sve2_fcvtn_bh, TCG_CALL_NO_RWG, void, ptr, ptr, env, i32)\n \n DEF_HELPER_FLAGS_5(advsimd_fcvt_bs, TCG_CALL_NO_RWG, void, ptr, ptr, ptr, env, i32)\ndiff --git a/target/arm/tcg/fp8_helper.c b/target/arm/tcg/fp8_helper.c\nindex fecd9cca0b..9bc1349950 100644\n--- a/target/arm/tcg/fp8_helper.c\n+++ b/target/arm/tcg/fp8_helper.c\n@@ -481,6 +481,46 @@ void HELPER(gvec_fcvt_bh)(void *vd, void *vn, void *vm,\n     clear_tail(vd, oprsz, simd_maxsz(desc));\n }\n \n+void HELPER(sve2_fcvtn_bh)(void *vd, void *vn, CPUARMState *env, uint32_t desc)\n+{\n+    FP8Context ctx = fp8_dst_start(env, desc);\n+    uint16_t *n0 = vn;\n+    uint16_t *n1 = vn + sizeof(ARMVectorReg);\n+    uint8_t *d = vd;\n+    bool osc = FIELD_EX64(env->vfp.fpmr, FPMR, OSC);\n+    size_t oprsz = simd_oprsz(desc);\n+    size_t nelem = oprsz / 2;\n+\n+    switch (ctx.f8fmt) {\n+    case OFP8_E5M2:\n+        for (size_t i = 0; i < nelem; ++i) {\n+            float16 e0 = n0[H2(i)];\n+            float16 e1 = n1[H2(i)];\n+            d[H1(2 * i + 0)] =\n+                float16_to_float8_e5m2(e0, ctx.scale, osc, &ctx.stat);\n+            d[H1(2 * i + 1)] =\n+                float16_to_float8_e5m2(e1, ctx.scale, osc, &ctx.stat);\n+        }\n+        break;\n+    case OFP8_E4M3:\n+        for (size_t i = 0; i < nelem; ++i) {\n+            float16 e0 = n0[H2(i)];\n+            float16 e1 = n1[H2(i)];\n+            d[H1(2 * i + 0)] =\n+                float16_to_float8_e4m3(e0, ctx.scale, osc, &ctx.stat);\n+            d[H1(2 * i + 1)] =\n+                float16_to_float8_e4m3(e1, ctx.scale, osc, &ctx.stat);\n+        }\n+        break;\n+    default:\n+        float8_invalid_output(d, oprsz, &ctx.stat);\n+        break;\n+    }\n+\n+    fp8_finish(env, &ctx);\n+}\n+\n+\n void HELPER(advsimd_fcvt_bs)(void *vd, void *vn, void *vm,\n                              CPUARMState *env, uint32_t desc)\n {\ndiff --git a/target/arm/tcg/translate-sve.c b/target/arm/tcg/translate-sve.c\nindex 54f1b253c6..319a28e94a 100644\n--- a/target/arm/tcg/translate-sve.c\n+++ b/target/arm/tcg/translate-sve.c\n@@ -4098,6 +4098,8 @@ TRANS_FEAT(BF1CVTLT, aa64_sme2_or_sve2_f8cvt, do_f8cvt, a,\n TRANS_FEAT(BF2CVTLT, aa64_sme2_or_sve2_f8cvt, do_f8cvt, a,\n            gen_helper_sve2_bfcvt, true, true)\n \n+TRANS_FEAT(FCVTN, aa64_sme2_or_sve2_f8cvt, do_f8cvt,\n+           a, gen_helper_sve2_fcvtn_bh, false, false)\n TRANS_FEAT(BFCVTN, aa64_sme2_or_sve2_f8cvt, do_f8cvt,\n            a, gen_helper_sve2_bfcvtn_bh, false, false)\n \ndiff --git a/target/arm/tcg/sve.decode b/target/arm/tcg/sve.decode\nindex b6ef8ed8de..806953bc35 100644\n--- a/target/arm/tcg/sve.decode\n+++ b/target/arm/tcg/sve.decode\n@@ -1101,6 +1101,7 @@ BF2CVT          01100101 00 001 000 001111 ..... .....          @rd_rn_e0\n BF1CVTLT        01100101 00 001 001 001110 ..... .....          @rd_rn_e0\n BF2CVTLT        01100101 00 001 001 001111 ..... .....          @rd_rn_e0\n \n+FCVTN           01100101 00 001 010 001100 ....0 .....          @rd_rnx2 esz=1\n BFCVTN          01100101 00 001 010 001110 ....0 .....          @rd_rnx2 esz=1\n \n ### SVE FP Compare with Zero Group\n","prefixes":["v2","33/40"]}