target/arm: Consolidate cpreg updates in add_cpreg_to_hashtable

Put most of the value writeback to the same place,
and improve the comment that goes with them.

Signed-off-by: Richard Henderson <[email protected]>
Reviewed-by: Peter Maydell <[email protected]>
Message-id: 20220501055028[email protected]
Signed-off-by: Peter Maydell <[email protected]>

diff --git a/target/arm/helper.c b/target/arm/helper.c
index cbc873e3e60a46a7b9e467f0a15363120cdf3a23..8ee96d5c042ba7ad4b23037a292eaf08899664b7 100644 (file)
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -8543,10 +8543,19 @@ static void add_cpreg_to_hashtable(ARMCPU *cpu, const ARMCPRegInfo *r,
     *r2 = *r;
     r2->name = memcpy(r2 + 1, name, name_len);
 
-    /* Reset the secure state to the specific incoming state.  This is
-     * necessary as the register may have been defined with both states.
+    /*
+     * Update fields to match the instantiation, overwiting wildcards
+     * such as CP_ANY, ARM_CP_STATE_BOTH, or ARM_CP_SECSTATE_BOTH.
      */
+    r2->cp = cp;
+    r2->crm = crm;
+    r2->opc1 = opc1;
+    r2->opc2 = opc2;
+    r2->state = state;
     r2->secure = secstate;
+    if (opaque) {
+        r2->opaque = opaque;
+    }
 
     if (r->bank_fieldoffsets[0] && r->bank_fieldoffsets[1]) {
         /* Register is banked (using both entries in array).
@@ -8587,20 +8596,7 @@ static void add_cpreg_to_hashtable(ARMCPU *cpu, const ARMCPRegInfo *r,
 #endif
         }
     }
-    if (opaque) {
-        r2->opaque = opaque;
-    }
-    /* reginfo passed to helpers is correct for the actual access,
-     * and is never ARM_CP_STATE_BOTH:
-     */
-    r2->state = state;
-    /* Make sure reginfo passed to helpers for wildcarded regs
-     * has the correct crm/opc1/opc2 for this reg, not CP_ANY:
-     */
-    r2->cp = cp;
-    r2->crm = crm;
-    r2->opc1 = opc1;
-    r2->opc2 = opc2;
+
     /* By convention, for wildcarded registers only the first
      * entry is used for migration; the others are marked as
      * ALIAS so we don't try to transfer the register