target/arm: Convert Cyclic Redundancy Check

Backports commit 6c35d53f1bde7fe327c074473c3048d6e6f15e95 from qemu

qemu/target/arm/a32.decode

@@ -182,6 +182,15 @@ SMULTT           .... 0001 0110 .... 0000 .... 1110 ....      @rd0mn
 }
 MSR_imm          .... 0011 0110 .... 1111 .... .... ....      @msr_i r=1
 
+# Cyclic Redundancy Check
+
+CRC32B           .... 0001 0000 .... .... 0000 0100 ....      @rndm
+CRC32H           .... 0001 0010 .... .... 0000 0100 ....      @rndm
+CRC32W           .... 0001 0100 .... .... 0000 0100 ....      @rndm
+CRC32CB          .... 0001 0000 .... .... 0010 0100 ....      @rndm
+CRC32CH          .... 0001 0010 .... .... 0010 0100 ....      @rndm
+CRC32CW          .... 0001 0100 .... .... 0010 0100 ....      @rndm
+
 # Miscellaneous instructions
 
 %sysm            8:1 16:4

qemu/target/arm/t32.decode

@@ -172,6 +172,13 @@ QSUB             1111 1010 1000 .... 1111 .... 1010 ....      @rndm
 QDADD            1111 1010 1000 .... 1111 .... 1001 ....      @rndm
 QDSUB            1111 1010 1000 .... 1111 .... 1011 ....      @rndm
 
+CRC32B           1111 1010 1100 .... 1111 .... 1000 ....      @rndm
+CRC32H           1111 1010 1100 .... 1111 .... 1001 ....      @rndm
+CRC32W           1111 1010 1100 .... 1111 .... 1010 ....      @rndm
+CRC32CB          1111 1010 1101 .... 1111 .... 1000 ....      @rndm
+CRC32CH          1111 1010 1101 .... 1111 .... 1001 ....      @rndm
+CRC32CW          1111 1010 1101 .... 1111 .... 1010 ....      @rndm
+
 # Branches and miscellaneous control
 
 %msr_sysm        4:1 8:4

qemu/target/arm/translate.c

@@ -8632,6 +8632,58 @@ static bool trans_MSR_v7m(DisasContext *s, arg_MSR_v7m *a)
     return true;
 }
 
+/*
+ * Cyclic Redundancy Check
+ */
+
+static bool op_crc32(DisasContext *s, arg_rrr *a, bool c, MemOp sz)
+{
+    TCGContext *tcg_ctx = s->uc->tcg_ctx;
+    TCGv_i32 t1, t2, t3;
+
+    if (!dc_isar_feature(aa32_crc32, s)) {
+        return false;
+    }
+
+    t1 = load_reg(s, a->rn);
+    t2 = load_reg(s, a->rm);
+    switch (sz) {
+    case MO_8:
+        gen_uxtb(t2);
+        break;
+    case MO_16:
+        gen_uxth(t2);
+        break;
+    case MO_32:
+        break;
+    default:
+        g_assert_not_reached();
+    }
+    t3 = tcg_const_i32(tcg_ctx, 1 << sz);
+    if (c) {
+        gen_helper_crc32c(tcg_ctx, t1, t1, t2, t3);
+    } else {
+        gen_helper_crc32(tcg_ctx, t1, t1, t2, t3);
+    }
+    tcg_temp_free_i32(tcg_ctx, t2);
+    tcg_temp_free_i32(tcg_ctx, t3);
+    store_reg(s, a->rd, t1);
+    return true;
+}
+
+#define DO_CRC32(NAME, c, sz) \
+static bool trans_##NAME(DisasContext *s, arg_rrr *a)  \
+    { return op_crc32(s, a, c, sz); }
+
+DO_CRC32(CRC32B, false, MO_8)
+DO_CRC32(CRC32H, false, MO_16)
+DO_CRC32(CRC32W, false, MO_32)
+DO_CRC32(CRC32CB, true, MO_8)
+DO_CRC32(CRC32CH, true, MO_16)
+DO_CRC32(CRC32CW, true, MO_32)
+
+#undef DO_CRC32
+
 /*
  * Legacy decoder.
  */
@@ -8969,39 +9021,9 @@ static void disas_arm_insn(DisasContext *s, unsigned int insn)
             gen_bx(s, tmp);
             break;
         case 0x4:
-        {
+            /* crc32 */
-            /* crc32/crc32c */
+            /* All done in decodetree.  Illegal ops reach here.  */
-            uint32_t c = extract32(insn, 8, 4);
+            goto illegal_op;
-
-            /* Check this CPU supports ARMv8 CRC instructions.
-             * op1 == 3 is UNPREDICTABLE but handle as UNDEFINED.
-             * Bits 8, 10 and 11 should be zero.
-             */
-            if (!dc_isar_feature(aa32_crc32, s) || op1 == 0x3 || (c & 0xd) != 0) {
-                goto illegal_op;
-            }
-
-            rn = extract32(insn, 16, 4);
-            rd = extract32(insn, 12, 4);
-
-            tmp = load_reg(s, rn);
-            tmp2 = load_reg(s, rm);
-            if (op1 == 0) {
-                tcg_gen_andi_i32(tcg_ctx, tmp2, tmp2, 0xff);
-            } else if (op1 == 1) {
-                tcg_gen_andi_i32(tcg_ctx, tmp2, tmp2, 0xffff);
-            }
-            tmp3 = tcg_const_i32(tcg_ctx, 1 << op1);
-            if (c & 0x2) {
-                gen_helper_crc32c(tcg_ctx, tmp, tmp, tmp2, tmp3);
-            } else {
-                gen_helper_crc32(tcg_ctx, tmp, tmp, tmp2, tmp3);
-            }
-            tcg_temp_free_i32(tcg_ctx, tmp2);
-            tcg_temp_free_i32(tcg_ctx, tmp3);
-            store_reg(s, rd, tmp);
-            break;
-        }
         case 0x5:
             /* Saturating addition and subtraction.  */
             /* All done in decodetree.  Reach here for illegal ops.  */
@@ -10448,16 +10470,13 @@ static void disas_thumb2_insn(DisasContext *s, uint32_t insn)
                         goto illegal_op;
                     }
                     break;
-                case 0x20: /* crc32/crc32c */
+                case 0x20: /* crc32/crc32c, in decodetree */
                 case 0x21:
                 case 0x22:
                 case 0x28:
                 case 0x29:
                 case 0x2a:
-                    if (!dc_isar_feature(aa32_crc32, s)) {
+                    goto illegal_op;
-                        goto illegal_op;
-                    }
-                    break;
                 default:
                     goto illegal_op;
                 }
@@ -10486,33 +10505,6 @@ static void disas_thumb2_insn(DisasContext *s, uint32_t insn)
                 case 0x18: /* clz */
                     tcg_gen_clzi_i32(tcg_ctx, tmp, tmp, 32);
                     break;
-                case 0x20:
-                case 0x21:
-                case 0x22:
-                case 0x28:
-                case 0x29:
-                case 0x2a:
-                {
-                    /* crc32/crc32c */
-                    uint32_t sz = op & 0x3;
-                    uint32_t c = op & 0x8;
-
-                    tmp2 = load_reg(s, rm);
-                    if (sz == 0) {
-                        tcg_gen_andi_i32(tcg_ctx, tmp2, tmp2, 0xff);
-                    } else if (sz == 1) {
-                        tcg_gen_andi_i32(tcg_ctx, tmp2, tmp2, 0xffff);
-                    }
-                    tmp3 = tcg_const_i32(tcg_ctx, 1 << sz);
-                    if (c) {
-                        gen_helper_crc32c(tcg_ctx, tmp, tmp, tmp2, tmp3);
-                    } else {
-                        gen_helper_crc32(tcg_ctx, tmp, tmp, tmp2, tmp3);
-                    }
-                    tcg_temp_free_i32(tcg_ctx, tmp2);
-                    tcg_temp_free_i32(tcg_ctx, tmp3);
-                    break;
-                }
                 default:
                     g_assert_not_reached();
                 }