target/riscv: remove 'over' brconds from vector trans

All helpers that rely on vstart >= vl are now doing early exits using
the VSTART_CHECK_EARLY_EXIT() macro. This macro will not only exit the
helper but also clear vstart.

We're still left with brconds that are skipping the helper, which is the
only place where we're clearing vstart. The pattern goes like this:

    tcg_gen_brcond_tl(TCG_COND_GEU, cpu_vstart, cpu_vl, over);
    (... calls helper that clears vstart ...)
    gen_set_label(over);
    return true;

This means that every time we jump to 'over' we're not clearing vstart,
which is an oversight that we're doing across the board.

Instead of setting vstart = 0 manually after each 'over' jump, remove
those brconds that are skipping helpers. The exception will be
trans_vmv_s_x() and trans_vfmv_s_f(): they don't use a helper and are
already clearing vstart manually in the 'over' label.

While we're at it, remove the (vl == 0) brconds from trans_rvbf16.c.inc
too since they're unneeded.

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20240314175704.478276-8-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

1 files changed, 0 insertions, 18 deletions

diff --git a/target/riscv/insn_trans/trans_rvvk.c.inc b/target/riscv/insn_trans/trans_rvvk.c.inc
index a5cdd1b67f..6d640e4596 100644
--- a/target/riscv/insn_trans/trans_rvvk.c.inc
+++ b/target/riscv/insn_trans/trans_rvvk.c.inc
@@ -164,8 +164,6 @@ GEN_OPIVX_GVEC_TRANS_CHECK(vandn_vx, andcs, zvkb_vx_check)
                 gen_helper_##NAME##_w,                                     \
                 gen_helper_##NAME##_d,                                     \
             };                                                             \
-            TCGLabel *over = gen_new_label();                              \
-            tcg_gen_brcond_tl(TCG_COND_GEU, cpu_vstart, cpu_vl, over);     \
                                                                            \
             data = FIELD_DP32(data, VDATA, VM, a->vm);                     \
             data = FIELD_DP32(data, VDATA, LMUL, s->lmul);                 \
@@ -177,7 +175,6 @@ GEN_OPIVX_GVEC_TRANS_CHECK(vandn_vx, andcs, zvkb_vx_check)
                                s->cfg_ptr->vlenb, s->cfg_ptr->vlenb,       \
                                data, fns[s->sew]);                         \
             mark_vs_dirty(s);                                              \
-            gen_set_label(over);                                           \
             return true;                                                   \
         }                                                                  \
         return false;                                                      \
@@ -249,14 +246,12 @@ GEN_OPIVI_WIDEN_TRANS(vwsll_vi, IMM_ZX, vwsll_vx, vwsll_vx_check)
             TCGv_ptr rd_v, rs2_v;                                             \
             TCGv_i32 desc, egs;                                               \
             uint32_t data = 0;                                                \
-            TCGLabel *over = gen_new_label();                                 \
                                                                               \
             if (!s->vstart_eq_zero || !s->vl_eq_vlmax) {                      \
                 /* save opcode for unwinding in case we throw an exception */ \
                 decode_save_opc(s);                                           \
                 egs = tcg_constant_i32(EGS);                                  \
                 gen_helper_egs_check(egs, tcg_env);                           \
-                tcg_gen_brcond_tl(TCG_COND_GEU, cpu_vstart, cpu_vl, over);    \
             }                                                                 \
                                                                               \
             data = FIELD_DP32(data, VDATA, VM, a->vm);                        \
@@ -272,7 +267,6 @@ GEN_OPIVI_WIDEN_TRANS(vwsll_vi, IMM_ZX, vwsll_vx, vwsll_vx_check)
             tcg_gen_addi_ptr(rs2_v, tcg_env, vreg_ofs(s, a->rs2));            \
             gen_helper_##NAME(rd_v, rs2_v, tcg_env, desc);                    \
             mark_vs_dirty(s);                                                 \
-            gen_set_label(over);                                              \
             return true;                                                      \
         }                                                                     \
         return false;                                                         \
@@ -325,14 +319,12 @@ GEN_V_UNMASKED_TRANS(vaesem_vs, vaes_check_vs, ZVKNED_EGS)
             TCGv_ptr rd_v, rs2_v;                                             \
             TCGv_i32 uimm_v, desc, egs;                                       \
             uint32_t data = 0;                                                \
-            TCGLabel *over = gen_new_label();                                 \
                                                                               \
             if (!s->vstart_eq_zero || !s->vl_eq_vlmax) {                      \
                 /* save opcode for unwinding in case we throw an exception */ \
                 decode_save_opc(s);                                           \
                 egs = tcg_constant_i32(EGS);                                  \
                 gen_helper_egs_check(egs, tcg_env);                           \
-                tcg_gen_brcond_tl(TCG_COND_GEU, cpu_vstart, cpu_vl, over);    \
             }                                                                 \
                                                                               \
             data = FIELD_DP32(data, VDATA, VM, a->vm);                        \
@@ -350,7 +342,6 @@ GEN_V_UNMASKED_TRANS(vaesem_vs, vaes_check_vs, ZVKNED_EGS)
             tcg_gen_addi_ptr(rs2_v, tcg_env, vreg_ofs(s, a->rs2));            \
             gen_helper_##NAME(rd_v, rs2_v, uimm_v, tcg_env, desc);            \
             mark_vs_dirty(s);                                                 \
-            gen_set_label(over);                                              \
             return true;                                                      \
         }                                                                     \
         return false;                                                         \
@@ -394,7 +385,6 @@ GEN_VI_UNMASKED_TRANS(vaeskf2_vi, vaeskf2_check, ZVKNED_EGS)
     {                                                                         \
         if (CHECK(s, a)) {                                                    \
             uint32_t data = 0;                                                \
-            TCGLabel *over = gen_new_label();                                 \
             TCGv_i32 egs;                                                     \
                                                                               \
             if (!s->vstart_eq_zero || !s->vl_eq_vlmax) {                      \
@@ -402,7 +392,6 @@ GEN_VI_UNMASKED_TRANS(vaeskf2_vi, vaeskf2_check, ZVKNED_EGS)
                 decode_save_opc(s);                                           \
                 egs = tcg_constant_i32(EGS);                                  \
                 gen_helper_egs_check(egs, tcg_env);                           \
-                tcg_gen_brcond_tl(TCG_COND_GEU, cpu_vstart, cpu_vl, over);    \
             }                                                                 \
                                                                               \
             data = FIELD_DP32(data, VDATA, VM, a->vm);                        \
@@ -417,7 +406,6 @@ GEN_VI_UNMASKED_TRANS(vaeskf2_vi, vaeskf2_check, ZVKNED_EGS)
                                data, gen_helper_##NAME);                      \
                                                                               \
             mark_vs_dirty(s);                                                 \
-            gen_set_label(over);                                              \
             return true;                                                      \
         }                                                                     \
         return false;                                                         \
@@ -448,7 +436,6 @@ static bool trans_vsha2cl_vv(DisasContext *s, arg_rmrr *a)
 {
     if (vsha_check(s, a)) {
         uint32_t data = 0;
-        TCGLabel *over = gen_new_label();
         TCGv_i32 egs;
 
         if (!s->vstart_eq_zero || !s->vl_eq_vlmax) {
@@ -456,7 +443,6 @@ static bool trans_vsha2cl_vv(DisasContext *s, arg_rmrr *a)
             decode_save_opc(s);
             egs = tcg_constant_i32(ZVKNH_EGS);
             gen_helper_egs_check(egs, tcg_env);
-            tcg_gen_brcond_tl(TCG_COND_GEU, cpu_vstart, cpu_vl, over);
         }
 
         data = FIELD_DP32(data, VDATA, VM, a->vm);
@@ -472,7 +458,6 @@ static bool trans_vsha2cl_vv(DisasContext *s, arg_rmrr *a)
                 gen_helper_vsha2cl32_vv : gen_helper_vsha2cl64_vv);
 
         mark_vs_dirty(s);
-        gen_set_label(over);
         return true;
     }
     return false;
@@ -482,7 +467,6 @@ static bool trans_vsha2ch_vv(DisasContext *s, arg_rmrr *a)
 {
     if (vsha_check(s, a)) {
         uint32_t data = 0;
-        TCGLabel *over = gen_new_label();
         TCGv_i32 egs;
 
         if (!s->vstart_eq_zero || !s->vl_eq_vlmax) {
@@ -490,7 +474,6 @@ static bool trans_vsha2ch_vv(DisasContext *s, arg_rmrr *a)
             decode_save_opc(s);
             egs = tcg_constant_i32(ZVKNH_EGS);
             gen_helper_egs_check(egs, tcg_env);
-            tcg_gen_brcond_tl(TCG_COND_GEU, cpu_vstart, cpu_vl, over);
         }
 
         data = FIELD_DP32(data, VDATA, VM, a->vm);
@@ -506,7 +489,6 @@ static bool trans_vsha2ch_vv(DisasContext *s, arg_rmrr *a)
                 gen_helper_vsha2ch32_vv : gen_helper_vsha2ch64_vv);
 
         mark_vs_dirty(s);
-        gen_set_label(over);
         return true;
     }
     return false;