Commit bd61776fee for qemu.org

commit bd61776fee728e14976e6ed13caabb5378ab4568
Author: Richard Henderson <richard.henderson@linaro.org>
Date:   Tue Jun 9 12:21:04 2026 -0700

    target/arm: Implement FMMLA (FP8 to FP32) for AdvSIMD

    Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
    Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
    Message-id: 20260609192110.752384-41-richard.henderson@linaro.org
    Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

diff --git a/target/arm/cpu-features.h b/target/arm/cpu-features.h
index 1745989bce..be3db5300f 100644
--- a/target/arm/cpu-features.h
+++ b/target/arm/cpu-features.h
@@ -1645,6 +1645,11 @@ static inline bool isar_feature_aa64_f8dp2(const ARMISARegisters *id)
     return FIELD_EX64_IDREG(id, ID_AA64FPFR0, F8DP2);
 }

+static inline bool isar_feature_aa64_f8mm8(const ARMISARegisters *id)
+{
+    return FIELD_EX64_IDREG(id, ID_AA64FPFR0, F8MM8);
+}
+
 /*
  * Combinations of feature tests, for ease of use with TRANS_FEAT.
  */
diff --git a/target/arm/tcg/a64.decode b/target/arm/tcg/a64.decode
index a3e404e7fe..6922e91010 100644
--- a/target/arm/tcg/a64.decode
+++ b/target/arm/tcg/a64.decode
@@ -1227,6 +1227,8 @@ FMLALL_sb_v     0.00 1110 0.0 rm:5 110001 rn:5 rd:5 \
 FDOT_sb_v       0.00 1110 000 ..... 11111 1 ..... ..... @qrrr_s
 FDOT_hb_v       0.00 1110 010 ..... 11111 1 ..... ..... @qrrr_h

+FMMLA_sb        0110 1110 100 ..... 11101 1 ..... ..... @rrr_q1e0
+
 ### Advanced SIMD scalar x indexed element

 FMUL_si         0101 1111 00 .. .... 1001 . 0 ..... .....   @rrx_h
diff --git a/target/arm/tcg/fp8_helper.c b/target/arm/tcg/fp8_helper.c
index 065df24b84..b9d4ba3b6a 100644
--- a/target/arm/tcg/fp8_helper.c
+++ b/target/arm/tcg/fp8_helper.c
@@ -807,3 +807,28 @@ void HELPER(gvec_fdot_idx_hb)(void *vd, void *vn, void *vm,

     clear_tail(vd, oprsz, simd_maxsz(desc));
 }
+
+void HELPER(gvec_fmmla_sb)(void *vd, void *vn, void *vm,
+                           CPUARMState *env, uint32_t desc)
+{
+    FP8MulContext ctx = fp8_mul_start(env, -1);
+    size_t oprsz = simd_oprsz(desc);
+    size_t nseg = oprsz / 16;
+    uint64_t *n = vn;
+    uint64_t *m = vm;
+    float32 *d = vd;
+
+    for (size_t seg = 0; seg < nseg; seg++, d += 4, n += 2, m += 2) {
+        float32 d0 = f8dotadd_s(n[0], m[0], 8, d[H4(0)], &ctx);
+        float32 d1 = f8dotadd_s(n[0], m[1], 8, d[H4(1)], &ctx);
+        float32 d2 = f8dotadd_s(n[1], m[0], 8, d[H4(2)], &ctx);
+        float32 d3 = f8dotadd_s(n[1], m[1], 8, d[H4(3)], &ctx);
+
+        d[H4(0)] = d0;
+        d[H4(1)] = d1;
+        d[H4(2)] = d2;
+        d[H4(3)] = d3;
+    }
+
+    clear_tail(vd, oprsz, simd_maxsz(desc));
+}
diff --git a/target/arm/tcg/helper-fp8-defs.h b/target/arm/tcg/helper-fp8-defs.h
index 5995d77577..3c74f02022 100644
--- a/target/arm/tcg/helper-fp8-defs.h
+++ b/target/arm/tcg/helper-fp8-defs.h
@@ -35,3 +35,5 @@ DEF_HELPER_FLAGS_5(gvec_fdot_idx_sb, TCG_CALL_NO_RWG, void, ptr, ptr, ptr, env,

 DEF_HELPER_FLAGS_5(gvec_fdot_hb, TCG_CALL_NO_RWG, void, ptr, ptr, ptr, env, i32)
 DEF_HELPER_FLAGS_5(gvec_fdot_idx_hb, TCG_CALL_NO_RWG, void, ptr, ptr, ptr, env, i32)
+
+DEF_HELPER_FLAGS_5(gvec_fmmla_sb, TCG_CALL_NO_RWG, void, ptr, ptr, ptr, env, i32)
diff --git a/target/arm/tcg/translate-a64.c b/target/arm/tcg/translate-a64.c
index e4c539fb18..ffe59b9471 100644
--- a/target/arm/tcg/translate-a64.c
+++ b/target/arm/tcg/translate-a64.c
@@ -7515,6 +7515,7 @@ static bool do_f8dot(DisasContext *s, arg_qrrr_e *a,

 TRANS_FEAT(FDOT_sb_v, aa64_f8dp4, do_f8dot, a, gen_helper_gvec_fdot_sb)
 TRANS_FEAT(FDOT_hb_v, aa64_f8dp2, do_f8dot, a, gen_helper_gvec_fdot_hb)
+TRANS_FEAT(FMMLA_sb, aa64_f8mm8, do_f8dot, a, gen_helper_gvec_fmmla_sb)

 static bool do_f8dot_idx(DisasContext *s, arg_qrrx_e *a,
                          gen_helper_gvec_3_ptr *fn)