target/arm: Convert Neon load/store multiple structures to decodetree

Convert the Neon "load/store multiple structures" insns to decodetree.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200430181003.21682-12-peter.maydell@linaro.org

target/arm/neon-ls.decode

@@ -27,3 +27,10 @@
 #   0b1111_1001_xxx0_xxxx_xxxx_xxxx_xxxx_xxxx
 # This file works on the A32 encoding only; calling code for T32 has to
 # transform the insn into the A32 version first.
+
+%vd_dp  22:1 12:4
+
+# Neon load/store multiple structures
+
+VLDST_multiple 1111 0100 0 . l:1 0 rn:4 .... itype:4 size:2 align:2 rm:4 \
+               vd=%vd_dp

target/arm/translate-neon.inc.c

@@ -274,3 +274,127 @@ static bool trans_VFML_scalar(DisasContext *s, arg_VFML_scalar *a)
                        gen_helper_gvec_fmlal_idx_a32);
     return true;
 }
+
+static struct {
+    int nregs;
+    int interleave;
+    int spacing;
+} const neon_ls_element_type[11] = {
+    {1, 4, 1},
+    {1, 4, 2},
+    {4, 1, 1},
+    {2, 2, 2},
+    {1, 3, 1},
+    {1, 3, 2},
+    {3, 1, 1},
+    {1, 1, 1},
+    {1, 2, 1},
+    {1, 2, 2},
+    {2, 1, 1}
+};
+
+static void gen_neon_ldst_base_update(DisasContext *s, int rm, int rn,
+                                      int stride)
+{
+    if (rm != 15) {
+        TCGv_i32 base;
+
+        base = load_reg(s, rn);
+        if (rm == 13) {
+            tcg_gen_addi_i32(base, base, stride);
+        } else {
+            TCGv_i32 index;
+            index = load_reg(s, rm);
+            tcg_gen_add_i32(base, base, index);
+            tcg_temp_free_i32(index);
+        }
+        store_reg(s, rn, base);
+    }
+}
+
+static bool trans_VLDST_multiple(DisasContext *s, arg_VLDST_multiple *a)
+{
+    /* Neon load/store multiple structures */
+    int nregs, interleave, spacing, reg, n;
+    MemOp endian = s->be_data;
+    int mmu_idx = get_mem_index(s);
+    int size = a->size;
+    TCGv_i64 tmp64;
+    TCGv_i32 addr, tmp;
+
+    if (!arm_dc_feature(s, ARM_FEATURE_NEON)) {
+        return false;
+    }
+
+    /* UNDEF accesses to D16-D31 if they don't exist */
+    if (!dc_isar_feature(aa32_simd_r32, s) && (a->vd & 0x10)) {
+        return false;
+    }
+    if (a->itype > 10) {
+        return false;
+    }
+    /* Catch UNDEF cases for bad values of align field */
+    switch (a->itype & 0xc) {
+    case 4:
+        if (a->align >= 2) {
+            return false;
+        }
+        break;
+    case 8:
+        if (a->align == 3) {
+            return false;
+        }
+        break;
+    default:
+        break;
+    }
+    nregs = neon_ls_element_type[a->itype].nregs;
+    interleave = neon_ls_element_type[a->itype].interleave;
+    spacing = neon_ls_element_type[a->itype].spacing;
+    if (size == 3 && (interleave | spacing) != 1) {
+        return false;
+    }
+
+    if (!vfp_access_check(s)) {
+        return true;
+    }
+
+    /* For our purposes, bytes are always little-endian.  */
+    if (size == 0) {
+        endian = MO_LE;
+    }
+    /*
+     * Consecutive little-endian elements from a single register
+     * can be promoted to a larger little-endian operation.
+     */
+    if (interleave == 1 && endian == MO_LE) {
+        size = 3;
+    }
+    tmp64 = tcg_temp_new_i64();
+    addr = tcg_temp_new_i32();
+    tmp = tcg_const_i32(1 << size);
+    load_reg_var(s, addr, a->rn);
+    for (reg = 0; reg < nregs; reg++) {
+        for (n = 0; n < 8 >> size; n++) {
+            int xs;
+            for (xs = 0; xs < interleave; xs++) {
+                int tt = a->vd + reg + spacing * xs;
+
+                if (a->l) {
+                    gen_aa32_ld_i64(s, tmp64, addr, mmu_idx, endian | size);
+                    neon_store_element64(tt, n, size, tmp64);
+                } else {
+                    neon_load_element64(tmp64, tt, n, size);
+                    gen_aa32_st_i64(s, tmp64, addr, mmu_idx, endian | size);
+                }
+                tcg_gen_add_i32(addr, addr, tmp);
+            }
+        }
+    }
+    tcg_temp_free_i32(addr);
+    tcg_temp_free_i32(tmp);
+    tcg_temp_free_i64(tmp64);
+
+    gen_neon_ldst_base_update(s, a->rm, a->rn, nregs * interleave * 8);
+    return true;
+}

target/arm/translate.c

@@ -3214,45 +3214,19 @@ static void gen_neon_trn_u16(TCGv_i32 t0, TCGv_i32 t1)
 }
 
 
-static struct {
-    int nregs;
-    int interleave;
-    int spacing;
-} const neon_ls_element_type[11] = {
-    {1, 4, 1},
-    {1, 4, 2},
-    {4, 1, 1},
-    {2, 2, 2},
-    {1, 3, 1},
-    {1, 3, 2},
-    {3, 1, 1},
-    {1, 1, 1},
-    {1, 2, 1},
-    {1, 2, 2},
-    {2, 1, 1}
-};
-
 /* Translate a NEON load/store element instruction.  Return nonzero if the
    instruction is invalid.  */
 static int disas_neon_ls_insn(DisasContext *s, uint32_t insn)
 {
     int rd, rn, rm;
-    int op;
     int nregs;
-    int interleave;
-    int spacing;
     int stride;
     int size;
     int reg;
     int load;
-    int n;
     int vec_size;
-    int mmu_idx;
-    MemOp endian;
     TCGv_i32 addr;
     TCGv_i32 tmp;
-    TCGv_i32 tmp2;
-    TCGv_i64 tmp64;
 
     if (!arm_dc_feature(s, ARM_FEATURE_NEON)) {
         return 1;
@@ -3274,70 +3248,9 @@ static int disas_neon_ls_insn(DisasContext *s, uint32_t insn)
     rn = (insn >> 16) & 0xf;
     rm = insn & 0xf;
     load = (insn & (1 << 21)) != 0;
-    endian = s->be_data;
-    mmu_idx = get_mem_index(s);
     if ((insn & (1 << 23)) == 0) {
-        /* Load store all elements.  */
+        /* Load store all elements -- handled already by decodetree */
-        op = (insn >> 8) & 0xf;
+        return 1;
-        size = (insn >> 6) & 3;
-        if (op > 10)
-            return 1;
-        /* Catch UNDEF cases for bad values of align field */
-        switch (op & 0xc) {
-        case 4:
-            if (((insn >> 5) & 1) == 1) {
-                return 1;
-            }
-            break;
-        case 8:
-            if (((insn >> 4) & 3) == 3) {
-                return 1;
-            }
-            break;
-        default:
-            break;
-        }
-        nregs = neon_ls_element_type[op].nregs;
-        interleave = neon_ls_element_type[op].interleave;
-        spacing = neon_ls_element_type[op].spacing;
-        if (size == 3 && (interleave | spacing) != 1) {
-            return 1;
-        }
-        /* For our purposes, bytes are always little-endian.  */
-        if (size == 0) {
-            endian = MO_LE;
-        }
-        /* Consecutive little-endian elements from a single register
-         * can be promoted to a larger little-endian operation.
-         */
-        if (interleave == 1 && endian == MO_LE) {
-            size = 3;
-        }
-        tmp64 = tcg_temp_new_i64();
-        addr = tcg_temp_new_i32();
-        tmp2 = tcg_const_i32(1 << size);
-        load_reg_var(s, addr, rn);
-        for (reg = 0; reg < nregs; reg++) {
-            for (n = 0; n < 8 >> size; n++) {
-                int xs;
-                for (xs = 0; xs < interleave; xs++) {
-                    int tt = rd + reg + spacing * xs;
-
-                    if (load) {
-                        gen_aa32_ld_i64(s, tmp64, addr, mmu_idx, endian | size);
-                        neon_store_element64(tt, n, size, tmp64);
-                    } else {
-                        neon_load_element64(tmp64, tt, n, size);
-                        gen_aa32_st_i64(s, tmp64, addr, mmu_idx, endian | size);
-                    }
-                    tcg_gen_add_i32(addr, addr, tmp2);
-                }
-            }
-        }
-        tcg_temp_free_i32(addr);
-        tcg_temp_free_i32(tmp2);
-        tcg_temp_free_i64(tmp64);
-        stride = nregs * interleave * 8;
     } else {
         size = (insn >> 10) & 3;
         if (size == 3) {