target/arm: Implement fp16 for Neon VRINT-with-specified-rounding-mode

Convert the Neon VRINT-with-specified-rounding-mode insns to gvec,
and use this to implement the fp16 versions.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200828183354.27913-41-peter.maydell@linaro.org

4 files changed, 30 insertions, 79 deletions

diff --git a/target/arm/helper.h b/target/arm/helper.h
index a2758ded28..83f7804dfe 100644
--- a/target/arm/helper.h
+++ b/target/arm/helper.h
@@ -214,7 +214,6 @@ DEF_HELPER_3(vfp_sqtoh, f16, i64, i32, ptr)
 DEF_HELPER_3(vfp_uqtoh, f16, i64, i32, ptr)
 
 DEF_HELPER_FLAGS_2(set_rmode, TCG_CALL_NO_RWG, i32, i32, ptr)
-DEF_HELPER_FLAGS_2(set_neon_rmode, TCG_CALL_NO_RWG, i32, i32, env)
 
 DEF_HELPER_FLAGS_3(vfp_fcvt_f16_to_f32, TCG_CALL_NO_RWG, f32, f16, ptr, i32)
 DEF_HELPER_FLAGS_3(vfp_fcvt_f32_to_f16, TCG_CALL_NO_RWG, f16, f32, ptr, i32)
@@ -638,6 +637,9 @@ DEF_HELPER_FLAGS_4(gvec_vcvt_rm_us, TCG_CALL_NO_RWG, void, ptr, ptr, ptr, i32)
 DEF_HELPER_FLAGS_4(gvec_vcvt_rm_sh, TCG_CALL_NO_RWG, void, ptr, ptr, ptr, i32)
 DEF_HELPER_FLAGS_4(gvec_vcvt_rm_uh, TCG_CALL_NO_RWG, void, ptr, ptr, ptr, i32)
 
+DEF_HELPER_FLAGS_4(gvec_vrint_rm_h, TCG_CALL_NO_RWG, void, ptr, ptr, ptr, i32)
+DEF_HELPER_FLAGS_4(gvec_vrint_rm_s, TCG_CALL_NO_RWG, void, ptr, ptr, ptr, i32)
+
 DEF_HELPER_FLAGS_4(gvec_frecpe_h, TCG_CALL_NO_RWG, void, ptr, ptr, ptr, i32)
 DEF_HELPER_FLAGS_4(gvec_frecpe_s, TCG_CALL_NO_RWG, void, ptr, ptr, ptr, i32)
 DEF_HELPER_FLAGS_4(gvec_frecpe_d, TCG_CALL_NO_RWG, void, ptr, ptr, ptr, i32)
diff --git a/target/arm/translate-neon.c.inc b/target/arm/translate-neon.c.inc
index 4ae6176ead..77a85d468f 100644
--- a/target/arm/translate-neon.c.inc
+++ b/target/arm/translate-neon.c.inc
@@ -3766,67 +3766,6 @@ static bool trans_VRINTX(DisasContext *s, arg_2misc *a)
     return do_2misc_fp(s, a, gen_helper_rints_exact);
 }
 
-static bool do_vrint(DisasContext *s, arg_2misc *a, int rmode)
-{
-    /*
-     * Handle a VRINT* operation by iterating 32 bits at a time,
-     * with a specified rounding mode in operation.
-     */
-    int pass;
-    TCGv_ptr fpst;
-    TCGv_i32 tcg_rmode;
-
-    if (!arm_dc_feature(s, ARM_FEATURE_NEON) ||
-        !arm_dc_feature(s, ARM_FEATURE_V8)) {
-        return false;
-    }
-
-    /* UNDEF accesses to D16-D31 if they don't exist. */
-    if (!dc_isar_feature(aa32_simd_r32, s) &&
-        ((a->vd | a->vm) & 0x10)) {
-        return false;
-    }
-
-    if (a->size != 2) {
-        /* TODO: FP16 will be the size == 1 case */
-        return false;
-    }
-
-    if ((a->vd | a->vm) & a->q) {
-        return false;
-    }
-
-    if (!vfp_access_check(s)) {
-        return true;
-    }
-
-    fpst = fpstatus_ptr(FPST_STD);
-    tcg_rmode = tcg_const_i32(arm_rmode_to_sf(rmode));
-    gen_helper_set_neon_rmode(tcg_rmode, tcg_rmode, cpu_env);
-    for (pass = 0; pass < (a->q ? 4 : 2); pass++) {
-        TCGv_i32 tmp = neon_load_reg(a->vm, pass);
-        gen_helper_rints(tmp, tmp, fpst);
-        neon_store_reg(a->vd, pass, tmp);
-    }
-    gen_helper_set_neon_rmode(tcg_rmode, tcg_rmode, cpu_env);
-    tcg_temp_free_i32(tcg_rmode);
-    tcg_temp_free_ptr(fpst);
-
-    return true;
-}
-
-#define DO_VRINT(INSN, RMODE)                                   \
-    static bool trans_##INSN(DisasContext *s, arg_2misc *a)     \
-    {                                                           \
-        return do_vrint(s, a, RMODE);                           \
-    }
-
-DO_VRINT(VRINTN, FPROUNDING_TIEEVEN)
-DO_VRINT(VRINTA, FPROUNDING_TIEAWAY)
-DO_VRINT(VRINTZ, FPROUNDING_ZERO)
-DO_VRINT(VRINTM, FPROUNDING_NEGINF)
-DO_VRINT(VRINTP, FPROUNDING_POSINF)
-
 #define DO_VEC_RMODE(INSN, RMODE, OP)                                   \
     static void gen_##INSN(unsigned vece, uint32_t rd_ofs,              \
                            uint32_t rm_ofs,                             \
@@ -3868,6 +3807,12 @@ DO_VEC_RMODE(VCVTPS, FPROUNDING_POSINF, vcvt_rm_s)
 DO_VEC_RMODE(VCVTMU, FPROUNDING_NEGINF, vcvt_rm_u)
 DO_VEC_RMODE(VCVTMS, FPROUNDING_NEGINF, vcvt_rm_s)
 
+DO_VEC_RMODE(VRINTN, FPROUNDING_TIEEVEN, vrint_rm_)
+DO_VEC_RMODE(VRINTA, FPROUNDING_TIEAWAY, vrint_rm_)
+DO_VEC_RMODE(VRINTZ, FPROUNDING_ZERO, vrint_rm_)
+DO_VEC_RMODE(VRINTM, FPROUNDING_NEGINF, vrint_rm_)
+DO_VEC_RMODE(VRINTP, FPROUNDING_POSINF, vrint_rm_)
+
 static bool trans_VSWP(DisasContext *s, arg_2misc *a)
 {
     TCGv_i64 rm, rd;
diff --git a/target/arm/vec_helper.c b/target/arm/vec_helper.c
index fae0fe7529..7ddf1e791c 100644
--- a/target/arm/vec_helper.c
+++ b/target/arm/vec_helper.c
@@ -1892,3 +1892,24 @@ DO_VCVT_RMODE(gvec_vcvt_rm_sh, helper_vfp_toshh, uint16_t)
 DO_VCVT_RMODE(gvec_vcvt_rm_uh, helper_vfp_touhh, uint16_t)
 
 #undef DO_VCVT_RMODE
+
+#define DO_VRINT_RMODE(NAME, FUNC, TYPE)                                \
+    void HELPER(NAME)(void *vd, void *vn, void *stat, uint32_t desc)    \
+    {                                                                   \
+        float_status *fpst = stat;                                      \
+        intptr_t i, oprsz = simd_oprsz(desc);                           \
+        uint32_t rmode = simd_data(desc);                               \
+        uint32_t prev_rmode = get_float_rounding_mode(fpst);            \
+        TYPE *d = vd, *n = vn;                                          \
+        set_float_rounding_mode(rmode, fpst);                           \
+        for (i = 0; i < oprsz / sizeof(TYPE); i++) {                    \
+            d[i] = FUNC(n[i], fpst);                                    \
+        }                                                               \
+        set_float_rounding_mode(prev_rmode, fpst);                      \
+        clear_tail(d, oprsz, simd_maxsz(desc));                         \
+    }
+
+DO_VRINT_RMODE(gvec_vrint_rm_h, helper_rinth, uint16_t)
+DO_VRINT_RMODE(gvec_vrint_rm_s, helper_rints, uint32_t)
+
+#undef DO_VRINT_RMODE
diff --git a/target/arm/vfp_helper.c b/target/arm/vfp_helper.c
index 8a3dd17681..5666393ef7 100644
--- a/target/arm/vfp_helper.c
+++ b/target/arm/vfp_helper.c
@@ -459,23 +459,6 @@ uint32_t HELPER(set_rmode)(uint32_t rmode, void *fpstp)
     return prev_rmode;
 }
 
-/* Set the current fp rounding mode in the standard fp status and return
- * the old one. This is for NEON instructions that need to change the
- * rounding mode but wish to use the standard FPSCR values for everything
- * else. Always set the rounding mode back to the correct value after
- * modifying it.
- * The argument is a softfloat float_round_ value.
- */
-uint32_t HELPER(set_neon_rmode)(uint32_t rmode, CPUARMState *env)
-{
-    float_status *fp_status = &env->vfp.standard_fp_status;
-
-    uint32_t prev_rmode = get_float_rounding_mode(fp_status);
-    set_float_rounding_mode(rmode, fp_status);
-
-    return prev_rmode;
-}
-
 /* Half precision conversions.  */
 float32 HELPER(vfp_fcvt_f16_to_f32)(uint32_t a, void *fpstp, uint32_t ahp_mode)
 {