target/arm: Move VLLDM and VLSTM to vfp.decode

Now that we no longer have an early check for ARM_FEATURE_VFP,
we can use the proper ISA check in trans_VLLDM_VLSTM.

Backports commit dc778a6873f534817a13257be2acba3ca87ec015 from qemu

qemu/target/arm/translate-vfp.inc.c

@@ -2879,3 +2879,43 @@ static bool trans_VCVT_dp_int(DisasContext *s, arg_VCVT_dp_int *a)
     tcg_temp_free_ptr(tcg_ctx, fpst);
     return true;
 }
+
+/*
+ * Decode VLLDM and VLSTM are nonstandard because:
+ *  * if there is no FPU then these insns must NOP in
+ *    Secure state and UNDEF in Nonsecure state
+ *  * if there is an FPU then these insns do not have
+ *    the usual behaviour that vfp_access_check() provides of
+ *    being controlled by CPACR/NSACR enable bits or the
+ *    lazy-stacking logic.
+ */
+static bool trans_VLLDM_VLSTM(DisasContext *s, arg_VLLDM_VLSTM *a)
+{
+    TCGContext *tcg_ctx = s->uc->tcg_ctx;
+    TCGv_i32 fptr;
+
+    if (!arm_dc_feature(s, ARM_FEATURE_M) ||
+        !arm_dc_feature(s, ARM_FEATURE_V8)) {
+        return false;
+    }
+    /* If not secure, UNDEF. */
+    if (!s->v8m_secure) {
+        return false;
+    }
+    /* If no fpu, NOP. */
+    if (!dc_isar_feature(aa32_vfp, s)) {
+        return true;
+    }
+
+    fptr = load_reg(s, a->rn);
+    if (a->l) {
+        gen_helper_v7m_vlldm(tcg_ctx, tcg_ctx->cpu_env, fptr);
+    } else {
+        gen_helper_v7m_vlstm(tcg_ctx, tcg_ctx->cpu_env, fptr);
+    }
+    tcg_temp_free_i32(tcg_ctx, fptr);
+
+    /* End the TB, because we have updated FP control bits */
+    s->base.is_jmp = DISAS_UPDATE;
+    return true;
+}

qemu/target/arm/translate.c

@@ -11270,54 +11270,18 @@ static void disas_thumb2_insn(DisasContext *s, uint32_t insn)
                 goto illegal_op; /* op0 = 0b11 : unallocated */
             }
 
-            /*
+            if (disas_vfp_insn(s, insn)) {
-             * Decode VLLDM and VLSTM first: these are nonstandard because:
+                if (((insn >> 8) & 0xe) == 10 &&
-             *  * if there is no FPU then these insns must NOP in
+                    dc_isar_feature(aa32_fpsp_v2, s)) {
-             *    Secure state and UNDEF in Nonsecure state
+                    /* FP, and the CPU supports it */
-             *  * if there is an FPU then these insns do not have
-             *    the usual behaviour that disas_vfp_insn() provides of
-             *    being controlled by CPACR/NSACR enable bits or the
-             *    lazy-stacking logic.
-             */
-            if (arm_dc_feature(s, ARM_FEATURE_V8) &&
-                (insn & 0xffa00f00) == 0xec200a00) {
-                /* 0b1110_1100_0x1x_xxxx_xxxx_1010_xxxx_xxxx
-                 *  - VLLDM, VLSTM
-                 * We choose to UNDEF if the RAZ bits are non-zero.
-                 */
-                if (!s->v8m_secure || (insn & 0x0040f0ff)) {
                     goto illegal_op;
+                } else {
+                    /* All other insns: NOCP */
+                    gen_exception_insn(s, s->pc_curr, EXCP_NOCP,
+                                       syn_uncategorized(),
+                                       default_exception_el(s));
                 }
-
-                if (arm_dc_feature(s, ARM_FEATURE_VFP)) {
-                    TCGContext *tcg_ctx = s->uc->tcg_ctx;
-                    uint32_t rn = (insn >> 16) & 0xf;
-                    TCGv_i32 fptr = load_reg(s, rn);
-
-                    if (extract32(insn, 20, 1)) {
-                        gen_helper_v7m_vlldm(tcg_ctx, tcg_ctx->cpu_env, fptr);
-                    } else {
-                        gen_helper_v7m_vlstm(tcg_ctx, tcg_ctx->cpu_env, fptr);
-                    }
-                    tcg_temp_free_i32(tcg_ctx, fptr);
-
-                    /* End the TB, because we have updated FP control bits */
-                    s->base.is_jmp = DISAS_UPDATE;
-                }
-                break;
             }
-            if (arm_dc_feature(s, ARM_FEATURE_VFP) &&
-                ((insn >> 8) & 0xe) == 10) {
-                /* FP, and the CPU supports it */
-                if (disas_vfp_insn(s, insn)) {
-                    goto illegal_op;
-                }
-                break;
-            }
-
-            /* All other insns: NOCP */
-            gen_exception_insn(s, s->pc_curr, EXCP_NOCP, syn_uncategorized(),
-                               default_exception_el(s));
             break;
         }
         if ((insn & 0xfe000a00) == 0xfc000800

qemu/target/arm/vfp.decode

@@ -242,3 +242,5 @@ VCVT_sp_int  ---- 1110 1.11 110 s:1 .... 1010 rz:1 1.0 .... \
              vd=%vd_sp vm=%vm_sp
 VCVT_dp_int  ---- 1110 1.11 110 s:1 .... 1011 rz:1 1.0 .... \
              vd=%vd_sp vm=%vm_dp
+
+VLLDM_VLSTM  1110 1100 001 l:1 rn:4 0000 1010 0000 0000