target/arm: Use tcg_gen_atomic_cmpxchg_i128 for STXP

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20221112042555.2622152-2-richard.henderson@linaro.org>

3 files changed, 35 insertions, 135 deletions

diff --git a/target/arm/helper-a64.c b/target/arm/helper-a64.c
index 77a8502..7dbdb2c 100644
--- a/target/arm/helper-a64.c
+++ b/target/arm/helper-a64.c
@@ -505,110 +505,6 @@ uint64_t HELPER(crc32c_64)(uint64_t acc, uint64_t val, uint32_t bytes)
     return crc32c(acc, buf, bytes) ^ 0xffffffff;
 }
 
-uint64_t HELPER(paired_cmpxchg64_le)(CPUARMState *env, uint64_t addr,
-                                     uint64_t new_lo, uint64_t new_hi)
-{
-    Int128 cmpv = int128_make128(env->exclusive_val, env->exclusive_high);
-    Int128 newv = int128_make128(new_lo, new_hi);
-    Int128 oldv;
-    uintptr_t ra = GETPC();
-    uint64_t o0, o1;
-    bool success;
-    int mem_idx = cpu_mmu_index(env, false);
-    MemOpIdx oi0 = make_memop_idx(MO_LEUQ | MO_ALIGN_16, mem_idx);
-    MemOpIdx oi1 = make_memop_idx(MO_LEUQ, mem_idx);
-
-    o0 = cpu_ldq_le_mmu(env, addr + 0, oi0, ra);
-    o1 = cpu_ldq_le_mmu(env, addr + 8, oi1, ra);
-    oldv = int128_make128(o0, o1);
-
-    success = int128_eq(oldv, cmpv);
-    if (success) {
-        cpu_stq_le_mmu(env, addr + 0, int128_getlo(newv), oi1, ra);
-        cpu_stq_le_mmu(env, addr + 8, int128_gethi(newv), oi1, ra);
-    }
-
-    return !success;
-}
-
-uint64_t HELPER(paired_cmpxchg64_le_parallel)(CPUARMState *env, uint64_t addr,
-                                              uint64_t new_lo, uint64_t new_hi)
-{
-    Int128 oldv, cmpv, newv;
-    uintptr_t ra = GETPC();
-    bool success;
-    int mem_idx;
-    MemOpIdx oi;
-
-    assert(HAVE_CMPXCHG128);
-
-    mem_idx = cpu_mmu_index(env, false);
-    oi = make_memop_idx(MO_LE | MO_128 | MO_ALIGN, mem_idx);
-
-    cmpv = int128_make128(env->exclusive_val, env->exclusive_high);
-    newv = int128_make128(new_lo, new_hi);
-    oldv = cpu_atomic_cmpxchgo_le_mmu(env, addr, cmpv, newv, oi, ra);
-
-    success = int128_eq(oldv, cmpv);
-    return !success;
-}
-
-uint64_t HELPER(paired_cmpxchg64_be)(CPUARMState *env, uint64_t addr,
-                                     uint64_t new_lo, uint64_t new_hi)
-{
-    /*
-     * High and low need to be switched here because this is not actually a
-     * 128bit store but two doublewords stored consecutively
-     */
-    Int128 cmpv = int128_make128(env->exclusive_high, env->exclusive_val);
-    Int128 newv = int128_make128(new_hi, new_lo);
-    Int128 oldv;
-    uintptr_t ra = GETPC();
-    uint64_t o0, o1;
-    bool success;
-    int mem_idx = cpu_mmu_index(env, false);
-    MemOpIdx oi0 = make_memop_idx(MO_BEUQ | MO_ALIGN_16, mem_idx);
-    MemOpIdx oi1 = make_memop_idx(MO_BEUQ, mem_idx);
-
-    o1 = cpu_ldq_be_mmu(env, addr + 0, oi0, ra);
-    o0 = cpu_ldq_be_mmu(env, addr + 8, oi1, ra);
-    oldv = int128_make128(o0, o1);
-
-    success = int128_eq(oldv, cmpv);
-    if (success) {
-        cpu_stq_be_mmu(env, addr + 0, int128_gethi(newv), oi1, ra);
-        cpu_stq_be_mmu(env, addr + 8, int128_getlo(newv), oi1, ra);
-    }
-
-    return !success;
-}
-
-uint64_t HELPER(paired_cmpxchg64_be_parallel)(CPUARMState *env, uint64_t addr,
-                                              uint64_t new_lo, uint64_t new_hi)
-{
-    Int128 oldv, cmpv, newv;
-    uintptr_t ra = GETPC();
-    bool success;
-    int mem_idx;
-    MemOpIdx oi;
-
-    assert(HAVE_CMPXCHG128);
-
-    mem_idx = cpu_mmu_index(env, false);
-    oi = make_memop_idx(MO_BE | MO_128 | MO_ALIGN, mem_idx);
-
-    /*
-     * High and low need to be switched here because this is not actually a
-     * 128bit store but two doublewords stored consecutively
-     */
-    cmpv = int128_make128(env->exclusive_high, env->exclusive_val);
-    newv = int128_make128(new_hi, new_lo);
-    oldv = cpu_atomic_cmpxchgo_be_mmu(env, addr, cmpv, newv, oi, ra);
-
-    success = int128_eq(oldv, cmpv);
-    return !success;
-}
-
 /* Writes back the old data into Rs.  */
 void HELPER(casp_le_parallel)(CPUARMState *env, uint32_t rs, uint64_t addr,
                               uint64_t new_lo, uint64_t new_hi)
diff --git a/target/arm/helper-a64.h b/target/arm/helper-a64.h
index 7b70657..94065d1 100644
--- a/target/arm/helper-a64.h
+++ b/target/arm/helper-a64.h
@@ -50,12 +50,6 @@ DEF_HELPER_FLAGS_2(frecpx_f16, TCG_CALL_NO_RWG, f16, f16, ptr)
 DEF_HELPER_FLAGS_2(fcvtx_f64_to_f32, TCG_CALL_NO_RWG, f32, f64, env)
 DEF_HELPER_FLAGS_3(crc32_64, TCG_CALL_NO_RWG_SE, i64, i64, i64, i32)
 DEF_HELPER_FLAGS_3(crc32c_64, TCG_CALL_NO_RWG_SE, i64, i64, i64, i32)
-DEF_HELPER_FLAGS_4(paired_cmpxchg64_le, TCG_CALL_NO_WG, i64, env, i64, i64, i64)
-DEF_HELPER_FLAGS_4(paired_cmpxchg64_le_parallel, TCG_CALL_NO_WG,
-                   i64, env, i64, i64, i64)
-DEF_HELPER_FLAGS_4(paired_cmpxchg64_be, TCG_CALL_NO_WG, i64, env, i64, i64, i64)
-DEF_HELPER_FLAGS_4(paired_cmpxchg64_be_parallel, TCG_CALL_NO_WG,
-                   i64, env, i64, i64, i64)
 DEF_HELPER_5(casp_le_parallel, void, env, i32, i64, i64, i64)
 DEF_HELPER_5(casp_be_parallel, void, env, i32, i64, i64, i64)
 DEF_HELPER_FLAGS_3(advsimd_maxh, TCG_CALL_NO_RWG, f16, f16, f16, ptr)
diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
index bbfadb7..951b64c 100644
--- a/target/arm/translate-a64.c
+++ b/target/arm/translate-a64.c
@@ -2601,32 +2601,42 @@ static void gen_store_exclusive(DisasContext *s, int rd, int rt, int rt2,
                                        get_mem_index(s),
                                        MO_64 | MO_ALIGN | s->be_data);
             tcg_gen_setcond_i64(TCG_COND_NE, tmp, tmp, cpu_exclusive_val);
-        } else if (tb_cflags(s->base.tb) & CF_PARALLEL) {
-            if (!HAVE_CMPXCHG128) {
-                gen_helper_exit_atomic(cpu_env);
-                /*
-                 * Produce a result so we have a well-formed opcode
-                 * stream when the following (dead) code uses 'tmp'.
-                 * TCG will remove the dead ops for us.
-                 */
-                tcg_gen_movi_i64(tmp, 0);
-            } else if (s->be_data == MO_LE) {
-                gen_helper_paired_cmpxchg64_le_parallel(tmp, cpu_env,
-                                                        cpu_exclusive_addr,
-                                                        cpu_reg(s, rt),
-                                                        cpu_reg(s, rt2));
-            } else {
-                gen_helper_paired_cmpxchg64_be_parallel(tmp, cpu_env,
-                                                        cpu_exclusive_addr,
-                                                        cpu_reg(s, rt),
-                                                        cpu_reg(s, rt2));
-            }
-        } else if (s->be_data == MO_LE) {
-            gen_helper_paired_cmpxchg64_le(tmp, cpu_env, cpu_exclusive_addr,
-                                           cpu_reg(s, rt), cpu_reg(s, rt2));
         } else {
-            gen_helper_paired_cmpxchg64_be(tmp, cpu_env, cpu_exclusive_addr,
-                                           cpu_reg(s, rt), cpu_reg(s, rt2));
+            TCGv_i128 t16 = tcg_temp_new_i128();
+            TCGv_i128 c16 = tcg_temp_new_i128();
+            TCGv_i64 a, b;
+
+            if (s->be_data == MO_LE) {
+                tcg_gen_concat_i64_i128(t16, cpu_reg(s, rt), cpu_reg(s, rt2));
+                tcg_gen_concat_i64_i128(c16, cpu_exclusive_val,
+                                        cpu_exclusive_high);
+            } else {
+                tcg_gen_concat_i64_i128(t16, cpu_reg(s, rt2), cpu_reg(s, rt));
+                tcg_gen_concat_i64_i128(c16, cpu_exclusive_high,
+                                        cpu_exclusive_val);
+            }
+
+            tcg_gen_atomic_cmpxchg_i128(t16, cpu_exclusive_addr, c16, t16,
+                                        get_mem_index(s),
+                                        MO_128 | MO_ALIGN | s->be_data);
+            tcg_temp_free_i128(c16);
+
+            a = tcg_temp_new_i64();
+            b = tcg_temp_new_i64();
+            if (s->be_data == MO_LE) {
+                tcg_gen_extr_i128_i64(a, b, t16);
+            } else {
+                tcg_gen_extr_i128_i64(b, a, t16);
+            }
+
+            tcg_gen_xor_i64(a, a, cpu_exclusive_val);
+            tcg_gen_xor_i64(b, b, cpu_exclusive_high);
+            tcg_gen_or_i64(tmp, a, b);
+            tcg_temp_free_i64(a);
+            tcg_temp_free_i64(b);
+            tcg_temp_free_i128(t16);
+
+            tcg_gen_setcondi_i64(TCG_COND_NE, tmp, tmp, 0);
         }
     } else {
         tcg_gen_atomic_cmpxchg_i64(tmp, cpu_exclusive_addr, cpu_exclusive_val,