[PATCH for-6.2 48/53] target/arm: Implement MVE VCVT between floating and fixed point

[Peter Maydell]

Implement the MVE VCVT insns which convert between floating and fixed
point.  As with the Neon equivalents, these use essentially the same
constant encoding as right-shift-by-immediate.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target/arm/helper-mve.h    |  9 +++++++++
 target/arm/mve.decode      | 19 +++++++++++++++++++
 target/arm/mve_helper.c    | 36 ++++++++++++++++++++++++++++++++++++
 target/arm/translate-mve.c | 18 ++++++++++++++++++
 4 files changed, 82 insertions(+)

diff --git a/target/arm/helper-mve.h b/target/arm/helper-mve.h
index 9ee841cdf01..f3c2b43bf43 100644
--- a/target/arm/helper-mve.h
+++ b/target/arm/helper-mve.h
@@ -863,3 +863,12 @@ DEF_HELPER_FLAGS_4(mve_vfma_scalars, TCG_CALL_NO_WG, void, 
env, ptr, ptr, i32)
 
 DEF_HELPER_FLAGS_4(mve_vfmas_scalarh, TCG_CALL_NO_WG, void, env, ptr, ptr, i32)
 DEF_HELPER_FLAGS_4(mve_vfmas_scalars, TCG_CALL_NO_WG, void, env, ptr, ptr, i32)
+
+DEF_HELPER_FLAGS_4(mve_vcvt_sh, TCG_CALL_NO_WG, void, env, ptr, ptr, i32)
+DEF_HELPER_FLAGS_4(mve_vcvt_uh, TCG_CALL_NO_WG, void, env, ptr, ptr, i32)
+DEF_HELPER_FLAGS_4(mve_vcvt_hs, TCG_CALL_NO_WG, void, env, ptr, ptr, i32)
+DEF_HELPER_FLAGS_4(mve_vcvt_hu, TCG_CALL_NO_WG, void, env, ptr, ptr, i32)
+DEF_HELPER_FLAGS_4(mve_vcvt_sf, TCG_CALL_NO_WG, void, env, ptr, ptr, i32)
+DEF_HELPER_FLAGS_4(mve_vcvt_uf, TCG_CALL_NO_WG, void, env, ptr, ptr, i32)
+DEF_HELPER_FLAGS_4(mve_vcvt_fs, TCG_CALL_NO_WG, void, env, ptr, ptr, i32)
+DEF_HELPER_FLAGS_4(mve_vcvt_fu, TCG_CALL_NO_WG, void, env, ptr, ptr, i32)
diff --git a/target/arm/mve.decode b/target/arm/mve.decode
index aa113279dc5..d9fcc42d36d 100644
--- a/target/arm/mve.decode
+++ b/target/arm/mve.decode
@@ -771,3 +771,22 @@ VCMLA0            1111 110 00 . 1 . ... 0 ... 0 1000 . 1 . 
0 ... 0 @2op_fp_size_
 VCMLA90           1111 110 01 . 1 . ... 0 ... 0 1000 . 1 . 0 ... 0 
@2op_fp_size_rev
 VCMLA180          1111 110 10 . 1 . ... 0 ... 0 1000 . 1 . 0 ... 0 
@2op_fp_size_rev
 VCMLA270          1111 110 11 . 1 . ... 0 ... 0 1000 . 1 . 0 ... 0 
@2op_fp_size_rev
+
+# floating-point <-> fixed-point conversions. Naming convention:
+# VCVT_<from><to>, S = signed int, U = unsigned int, H = halfprec, F = 
singleprec
+@vcvt             .... .... .. 1 ..... .... .. 1 . .... .... &2shift \
+                  qd=%qd qm=%qm shift=%rshift_i5 size=2
+@vcvt_f16         .... .... .. 11 .... .... .. 0 . .... .... &2shift \
+                  qd=%qd qm=%qm shift=%rshift_i4 size=1
+
+VCVT_SH_fixed     1110 1111 1 . ...... ... 0 11 . 0 01 . 1 ... 0 @vcvt_f16
+VCVT_UH_fixed     1111 1111 1 . ...... ... 0 11 . 0 01 . 1 ... 0 @vcvt_f16
+
+VCVT_HS_fixed     1110 1111 1 . ...... ... 0 11 . 1 01 . 1 ... 0 @vcvt_f16
+VCVT_HU_fixed     1111 1111 1 . ...... ... 0 11 . 1 01 . 1 ... 0 @vcvt_f16
+
+VCVT_SF_fixed     1110 1111 1 . ...... ... 0 11 . 0 01 . 1 ... 0 @vcvt
+VCVT_UF_fixed     1111 1111 1 . ...... ... 0 11 . 0 01 . 1 ... 0 @vcvt
+
+VCVT_FS_fixed     1110 1111 1 . ...... ... 0 11 . 1 01 . 1 ... 0 @vcvt
+VCVT_FU_fixed     1111 1111 1 . ...... ... 0 11 . 1 01 . 1 ... 0 @vcvt
diff --git a/target/arm/mve_helper.c b/target/arm/mve_helper.c
index 0aeccc12d69..8e1184db3b4 100644
--- a/target/arm/mve_helper.c
+++ b/target/arm/mve_helper.c
@@ -3263,3 +3263,39 @@ DO_VCMP_FP_BOTH(vfcmpgts, vfcmpgt_scalars, 4, uint32_t, 
DO_GT32)
 
 DO_VCMP_FP_BOTH(vfcmpleh, vfcmple_scalarh, 2, uint16_t, !DO_GT16)
 DO_VCMP_FP_BOTH(vfcmples, vfcmple_scalars, 4, uint32_t, !DO_GT32)
+
+#define DO_VCVT_FIXED(OP, ESIZE, TYPE, FN)                              \
+    void HELPER(glue(mve_, OP))(CPUARMState *env, void *vd, void *vm,   \
+                                uint32_t shift)                         \
+    {                                                                   \
+        TYPE *d = vd, *m = vm;                                          \
+        TYPE r;                                                         \
+        uint16_t mask = mve_element_mask(env);                          \
+        unsigned e;                                                     \
+        float_status *fpst;                                             \
+        float_status scratch_fpst;                                      \
+        for (e = 0; e < 16 / ESIZE; e++, mask >>= ESIZE) {              \
+            if ((mask & MAKE_64BIT_MASK(0, ESIZE)) == 0) {              \
+                continue;                                               \
+            }                                                           \
+            fpst = (ESIZE == 2) ? &env->vfp.standard_fp_status_f16 :    \
+                &env->vfp.standard_fp_status;                           \
+            if (!(mask & 1)) {                                          \
+                /* We need the result but without updating flags */     \
+                scratch_fpst = *fpst;                                   \
+                fpst = &scratch_fpst;                                   \
+            }                                                           \
+            r = FN(m[H##ESIZE(e)], shift, fpst);                        \
+            mergemask(&d[H##ESIZE(e)], r, mask);                        \
+        }                                                               \
+        mve_advance_vpt(env);                                           \
+    }
+
+DO_VCVT_FIXED(vcvt_sh, 2, int16_t, helper_vfp_shtoh)
+DO_VCVT_FIXED(vcvt_uh, 2, uint16_t, helper_vfp_uhtoh)
+DO_VCVT_FIXED(vcvt_hs, 2, int16_t, helper_vfp_toshh_round_to_zero)
+DO_VCVT_FIXED(vcvt_hu, 2, uint16_t, helper_vfp_touhh_round_to_zero)
+DO_VCVT_FIXED(vcvt_sf, 4, int32_t, helper_vfp_sltos)
+DO_VCVT_FIXED(vcvt_uf, 4, uint32_t, helper_vfp_ultos)
+DO_VCVT_FIXED(vcvt_fs, 4, int32_t, helper_vfp_tosls_round_to_zero)
+DO_VCVT_FIXED(vcvt_fu, 4, uint32_t, helper_vfp_touls_round_to_zero)
diff --git a/target/arm/translate-mve.c b/target/arm/translate-mve.c
index e8a3dec6683..9269dbc3324 100644
--- a/target/arm/translate-mve.c
+++ b/target/arm/translate-mve.c
@@ -1439,6 +1439,24 @@ DO_2SHIFT(VRSHRI_U, vrshli_u, true)
 DO_2SHIFT(VSRI, vsri, false)
 DO_2SHIFT(VSLI, vsli, false)
 
+#define DO_2SHIFT_FP(INSN, FN)                                  \
+    static bool trans_##INSN(DisasContext *s, arg_2shift *a)    \
+    {                                                           \
+        if (!dc_isar_feature(aa32_mve_fp, s)) {                 \
+            return false;                                       \
+        }                                                       \
+        return do_2shift(s, a, gen_helper_mve_##FN, false);     \
+    }
+
+DO_2SHIFT_FP(VCVT_SH_fixed, vcvt_sh)
+DO_2SHIFT_FP(VCVT_UH_fixed, vcvt_uh)
+DO_2SHIFT_FP(VCVT_HS_fixed, vcvt_hs)
+DO_2SHIFT_FP(VCVT_HU_fixed, vcvt_hu)
+DO_2SHIFT_FP(VCVT_SF_fixed, vcvt_sf)
+DO_2SHIFT_FP(VCVT_UF_fixed, vcvt_uf)
+DO_2SHIFT_FP(VCVT_FS_fixed, vcvt_fs)
+DO_2SHIFT_FP(VCVT_FU_fixed, vcvt_fu)
+
 static bool do_2shift_scalar(DisasContext *s, arg_shl_scalar *a,
                              MVEGenTwoOpShiftFn *fn)
 {
-- 
2.20.1