[PATCH 44/71] target/arm: Implement SME ZERO

[Richard Henderson]

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/helper-sme.h    |  2 ++
 target/arm/translate-a64.h |  1 +
 target/arm/sme.decode      |  4 ++++
 target/arm/sme_helper.c    | 25 +++++++++++++++++++++++++
 target/arm/translate-a64.c | 15 +++++++++++++++
 target/arm/translate-sme.c | 13 +++++++++++++
 6 files changed, 60 insertions(+)

diff --git a/target/arm/helper-sme.h b/target/arm/helper-sme.h
index 3bd48c235f..c4ee1f09e4 100644
--- a/target/arm/helper-sme.h
+++ b/target/arm/helper-sme.h
@@ -19,3 +19,5 @@
 
 DEF_HELPER_FLAGS_2(set_pstate_sm, TCG_CALL_NO_RWG, void, env, i32)
 DEF_HELPER_FLAGS_2(set_pstate_za, TCG_CALL_NO_RWG, void, env, i32)
+
+DEF_HELPER_FLAGS_3(sme_zero, TCG_CALL_NO_RWG, void, env, i32, i32)
diff --git a/target/arm/translate-a64.h b/target/arm/translate-a64.h
index 6bd1b2eb4b..ec5d580ba0 100644
--- a/target/arm/translate-a64.h
+++ b/target/arm/translate-a64.h
@@ -30,6 +30,7 @@ bool logic_imm_decode_wmask(uint64_t *result, unsigned int 
immn,
                             unsigned int imms, unsigned int immr);
 bool sve_access_check(DisasContext *s);
 bool sme_enabled_check(DisasContext *s);
+bool sme_za_enabled_check(DisasContext *s);
 TCGv_i64 clean_data_tbi(DisasContext *s, TCGv_i64 addr);
 TCGv_i64 gen_mte_check1(DisasContext *s, TCGv_i64 addr, bool is_write,
                         bool tag_checked, int log2_size);
diff --git a/target/arm/sme.decode b/target/arm/sme.decode
index c25c031a71..6e4483fdce 100644
--- a/target/arm/sme.decode
+++ b/target/arm/sme.decode
@@ -18,3 +18,7 @@
 #
 # This file is processed by scripts/decodetree.py
 #
+
+### SME Misc
+
+ZERO            11000000 00 001 00000000000 imm:8
diff --git a/target/arm/sme_helper.c b/target/arm/sme_helper.c
index c34d1b2e6b..4172b788f9 100644
--- a/target/arm/sme_helper.c
+++ b/target/arm/sme_helper.c
@@ -58,3 +58,28 @@ void helper_set_pstate_za(CPUARMState *env, uint32_t i)
         memset(env->zarray, 0, sizeof(env->zarray));
     }
 }
+
+void helper_sme_zero(CPUARMState *env, uint32_t imm, uint32_t svl)
+{
+    uint32_t i;
+
+    /*
+     * Special case clearing the entire ZA space.
+     * This falls into the CONSTRAINED UNPREDICTABLE zeroing of any
+     * parts of the ZA storage outside of SVL.
+     */
+    if (imm == 0xff) {
+        memset(env->zarray, 0, sizeof(env->zarray));
+        return;
+    }
+
+    /*
+     * Recall that ZAnH.D[m] is spread across ZA[n+8*m].
+     * Unless SVL == ARM_MAX_VQ, each row is discontiguous.
+     */
+    for (i = 0; i < svl; i++) {
+        if (imm & (1 << (i % 8))) {
+            memset(&env->zarray[i], 0, svl);
+        }
+    }
+}
diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
index 222f93d42d..660c5dbf5b 100644
--- a/target/arm/translate-a64.c
+++ b/target/arm/translate-a64.c
@@ -1231,6 +1231,21 @@ bool sme_enabled_check(DisasContext *s)
     return fp_access_check_only(s);
 }
 
+/* Note that this function corresponds to CheckSMEAndZAEnabled. */
+bool sme_za_enabled_check(DisasContext *s)
+{
+    if (!sme_enabled_check(s)) {
+        return false;
+    }
+    if (!s->pstate_za) {
+        gen_exception_insn(s, s->pc_curr, EXCP_UDEF,
+                           syn_smetrap(SME_ET_InactiveZA, false),
+                           default_exception_el(s));
+        return false;
+    }
+    return true;
+}
+
 /*
  * This utility function is for doing register extension with an
  * optional shift. You will likely want to pass a temporary for the
diff --git a/target/arm/translate-sme.c b/target/arm/translate-sme.c
index 786c93fb2d..d526c74456 100644
--- a/target/arm/translate-sme.c
+++ b/target/arm/translate-sme.c
@@ -33,3 +33,16 @@
  */
 
 #include "decode-sme.c.inc"
+
+
+static bool trans_ZERO(DisasContext *s, arg_ZERO *a)
+{
+    if (!dc_isar_feature(aa64_sme, s)) {
+        return false;
+    }
+    if (sme_za_enabled_check(s)) {
+        gen_helper_sme_zero(cpu_env, tcg_constant_i32(a->imm),
+                            tcg_constant_i32(s->svl));
+    }
+    return true;
+}
-- 
2.34.1