[PATCH v6 05/25] target/riscv: Add a tb flags field for vstart

[Richard Henderson <richard.henderson@linaro.org>]

From: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>

Once we mistook the vstart directly from the env->vstart. As env->vstart is not
a constant, we should record it in the tb flags if we want to use
it in translation.

Reported-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
Message-Id: <20230324143031.1093-5-zhiwei_liu@linux.alibaba.com>
---
 target/riscv/cpu.h                      |  1 +
 target/riscv/cpu_helper.c               |  1 +
 target/riscv/translate.c                |  4 ++--
 target/riscv/insn_trans/trans_rvv.c.inc | 14 +++++++-------
 4 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index d9e0eaaf9b..86a82e25dc 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -657,6 +657,7 @@ FIELD(TB_FLAGS, VMA, 21, 1)
 FIELD(TB_FLAGS, ITRIGGER, 22, 1)
 /* Virtual mode enabled */
 FIELD(TB_FLAGS, VIRT_ENABLED, 23, 1)
+FIELD(TB_FLAGS, VSTART_EQ_ZERO, 24, 1)
 
 #ifdef TARGET_RISCV32
 #define riscv_cpu_mxl(env)  ((void)(env), MXL_RV32)
diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index 4fdd6fe021..4f0999d50b 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -74,6 +74,7 @@ void cpu_get_tb_cpu_state(CPURISCVState *env, target_ulong *pc,
                     FIELD_EX64(env->vtype, VTYPE, VTA));
         flags = FIELD_DP32(flags, TB_FLAGS, VMA,
                     FIELD_EX64(env->vtype, VTYPE, VMA));
+        flags = FIELD_DP32(flags, TB_FLAGS, VSTART_EQ_ZERO, env->vstart == 0);
     } else {
         flags = FIELD_DP32(flags, TB_FLAGS, VILL, 1);
     }
diff --git a/target/riscv/translate.c b/target/riscv/translate.c
index 74d0b9889d..f8c077525c 100644
--- a/target/riscv/translate.c
+++ b/target/riscv/translate.c
@@ -97,7 +97,7 @@ typedef struct DisasContext {
     uint8_t vta;
     uint8_t vma;
     bool cfg_vta_all_1s;
-    target_ulong vstart;
+    bool vstart_eq_zero;
     bool vl_eq_vlmax;
     CPUState *cs;
     TCGv zero;
@@ -1155,7 +1155,7 @@ static void riscv_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cs)
     ctx->vta = FIELD_EX32(tb_flags, TB_FLAGS, VTA) && cpu->cfg.rvv_ta_all_1s;
     ctx->vma = FIELD_EX32(tb_flags, TB_FLAGS, VMA) && cpu->cfg.rvv_ma_all_1s;
     ctx->cfg_vta_all_1s = cpu->cfg.rvv_ta_all_1s;
-    ctx->vstart = env->vstart;
+    ctx->vstart_eq_zero = FIELD_EX32(tb_flags, TB_FLAGS, VSTART_EQ_ZERO);
     ctx->vl_eq_vlmax = FIELD_EX32(tb_flags, TB_FLAGS, VL_EQ_VLMAX);
     ctx->misa_mxl_max = env->misa_mxl_max;
     ctx->xl = FIELD_EX32(tb_flags, TB_FLAGS, XL);
diff --git a/target/riscv/insn_trans/trans_rvv.c.inc b/target/riscv/insn_trans/trans_rvv.c.inc
index 6297c3b50d..32b3b9a8e5 100644
--- a/target/riscv/insn_trans/trans_rvv.c.inc
+++ b/target/riscv/insn_trans/trans_rvv.c.inc
@@ -547,7 +547,7 @@ static bool vext_check_sds(DisasContext *s, int vd, int vs1, int vs2, int vm)
  */
 static bool vext_check_reduction(DisasContext *s, int vs2)
 {
-    return require_align(vs2, s->lmul) && (s->vstart == 0);
+    return require_align(vs2, s->lmul) && s->vstart_eq_zero;
 }
 
 /*
@@ -3083,7 +3083,7 @@ static bool trans_vcpop_m(DisasContext *s, arg_rmr *a)
 {
     if (require_rvv(s) &&
         vext_check_isa_ill(s) &&
-        s->vstart == 0) {
+        s->vstart_eq_zero) {
         TCGv_ptr src2, mask;
         TCGv dst;
         TCGv_i32 desc;
@@ -3112,7 +3112,7 @@ static bool trans_vfirst_m(DisasContext *s, arg_rmr *a)
 {
     if (require_rvv(s) &&
         vext_check_isa_ill(s) &&
-        s->vstart == 0) {
+        s->vstart_eq_zero) {
         TCGv_ptr src2, mask;
         TCGv dst;
         TCGv_i32 desc;
@@ -3146,7 +3146,7 @@ static bool trans_##NAME(DisasContext *s, arg_rmr *a)              \
         vext_check_isa_ill(s) &&                                   \
         require_vm(a->vm, a->rd) &&                                \
         (a->rd != a->rs2) &&                                       \
-        (s->vstart == 0)) {                                        \
+        s->vstart_eq_zero) {                                       \
         uint32_t data = 0;                                         \
         gen_helper_gvec_3_ptr *fn = gen_helper_##NAME;             \
         TCGLabel *over = gen_new_label();                          \
@@ -3187,7 +3187,7 @@ static bool trans_viota_m(DisasContext *s, arg_viota_m *a)
         !is_overlapped(a->rd, 1 << MAX(s->lmul, 0), a->rs2, 1) &&
         require_vm(a->vm, a->rd) &&
         require_align(a->rd, s->lmul) &&
-        (s->vstart == 0)) {
+        s->vstart_eq_zero) {
         uint32_t data = 0;
         TCGLabel *over = gen_new_label();
         tcg_gen_brcondi_tl(TCG_COND_EQ, cpu_vl, 0, over);
@@ -3636,7 +3636,7 @@ static bool vcompress_vm_check(DisasContext *s, arg_r *a)
            require_align(a->rs2, s->lmul) &&
            (a->rd != a->rs2) &&
            !is_overlapped(a->rd, 1 << MAX(s->lmul, 0), a->rs1, 1) &&
-           (s->vstart == 0);
+           s->vstart_eq_zero;
 }
 
 static bool trans_vcompress_vm(DisasContext *s, arg_r *a)
@@ -3675,7 +3675,7 @@ static bool trans_##NAME(DisasContext *s, arg_##NAME * a)               \
         QEMU_IS_ALIGNED(a->rd, LEN) &&                                  \
         QEMU_IS_ALIGNED(a->rs2, LEN)) {                                 \
         uint32_t maxsz = (s->cfg_ptr->vlen >> 3) * LEN;                 \
-        if (s->vstart == 0) {                                           \
+        if (s->vstart_eq_zero) {                                        \
             /* EEW = 8 */                                               \
             tcg_gen_gvec_mov(MO_8, vreg_ofs(s, a->rd),                  \
                              vreg_ofs(s, a->rs2), maxsz, maxsz);        \
-- 
2.34.1