target/arm: Implement SVE2 WHILERW, WHILEWR

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210525010358.152808-32-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

2 files changed, 70 insertions, 0 deletions

diff --git a/target/arm/sve.decode b/target/arm/sve.decode
index ae853d2..f365907 100644
--- a/target/arm/sve.decode
+++ b/target/arm/sve.decode
@@ -702,6 +702,9 @@ CTERM           00100101 1 sf:1 1 rm:5 001000 rn:5 ne:1 0000
 # SVE integer compare scalar count and limit
 WHILE           00100101 esz:2 1 rm:5 000 sf:1 u:1 lt:1 rn:5 eq:1 rd:4
 
+# SVE2 pointer conflict compare
+WHILE_ptr       00100101 esz:2 1 rm:5 001 100 rn:5 rw:1 rd:4
+
 ### SVE Integer Wide Immediate - Unpredicated Group
 
 # SVE broadcast floating-point immediate (unpredicated)
diff --git a/target/arm/translate-sve.c b/target/arm/translate-sve.c
index a55e747..64aecc2 100644
--- a/target/arm/translate-sve.c
+++ b/target/arm/translate-sve.c
@@ -3218,6 +3218,73 @@ static bool trans_WHILE(DisasContext *s, arg_WHILE *a)
     return true;
 }
 
+static bool trans_WHILE_ptr(DisasContext *s, arg_WHILE_ptr *a)
+{
+    TCGv_i64 op0, op1, diff, t1, tmax;
+    TCGv_i32 t2, t3;
+    TCGv_ptr ptr;
+    unsigned vsz = vec_full_reg_size(s);
+    unsigned desc = 0;
+
+    if (!dc_isar_feature(aa64_sve2, s)) {
+        return false;
+    }
+    if (!sve_access_check(s)) {
+        return true;
+    }
+
+    op0 = read_cpu_reg(s, a->rn, 1);
+    op1 = read_cpu_reg(s, a->rm, 1);
+
+    tmax = tcg_const_i64(vsz);
+    diff = tcg_temp_new_i64();
+
+    if (a->rw) {
+        /* WHILERW */
+        /* diff = abs(op1 - op0), noting that op0/1 are unsigned. */
+        t1 = tcg_temp_new_i64();
+        tcg_gen_sub_i64(diff, op0, op1);
+        tcg_gen_sub_i64(t1, op1, op0);
+        tcg_gen_movcond_i64(TCG_COND_GEU, diff, op0, op1, diff, t1);
+        tcg_temp_free_i64(t1);
+        /* Round down to a multiple of ESIZE.  */
+        tcg_gen_andi_i64(diff, diff, -1 << a->esz);
+        /* If op1 == op0, diff == 0, and the condition is always true. */
+        tcg_gen_movcond_i64(TCG_COND_EQ, diff, op0, op1, tmax, diff);
+    } else {
+        /* WHILEWR */
+        tcg_gen_sub_i64(diff, op1, op0);
+        /* Round down to a multiple of ESIZE.  */
+        tcg_gen_andi_i64(diff, diff, -1 << a->esz);
+        /* If op0 >= op1, diff <= 0, the condition is always true. */
+        tcg_gen_movcond_i64(TCG_COND_GEU, diff, op0, op1, tmax, diff);
+    }
+
+    /* Bound to the maximum.  */
+    tcg_gen_umin_i64(diff, diff, tmax);
+    tcg_temp_free_i64(tmax);
+
+    /* Since we're bounded, pass as a 32-bit type.  */
+    t2 = tcg_temp_new_i32();
+    tcg_gen_extrl_i64_i32(t2, diff);
+    tcg_temp_free_i64(diff);
+
+    desc = FIELD_DP32(desc, PREDDESC, OPRSZ, vsz / 8);
+    desc = FIELD_DP32(desc, PREDDESC, ESZ, a->esz);
+    t3 = tcg_const_i32(desc);
+
+    ptr = tcg_temp_new_ptr();
+    tcg_gen_addi_ptr(ptr, cpu_env, pred_full_reg_offset(s, a->rd));
+
+    gen_helper_sve_whilel(t2, ptr, t2, t3);
+    do_pred_flags(t2);
+
+    tcg_temp_free_ptr(ptr);
+    tcg_temp_free_i32(t2);
+    tcg_temp_free_i32(t3);
+    return true;
+}
+
 /*
  *** SVE Integer Wide Immediate - Unpredicated Group
  */