Do constant folding for shift operations.

Perform constant forlding for SHR, SHL, SAR, ROTR, ROTL operations.
Signed-off-by: NKirill Batuzov <batuzovk@ispras.ru>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

tcg/optimize.c

@@ -102,6 +102,11 @@ static int op_bits(int op)
     case INDEX_op_and_i32:
     case INDEX_op_or_i32:
     case INDEX_op_xor_i32:
+    case INDEX_op_shl_i32:
+    case INDEX_op_shr_i32:
+    case INDEX_op_sar_i32:
+    case INDEX_op_rotl_i32:
+    case INDEX_op_rotr_i32:
         return 32;
 #if TCG_TARGET_REG_BITS == 64
     case INDEX_op_mov_i64:
@@ -111,6 +116,11 @@ static int op_bits(int op)
     case INDEX_op_and_i64:
     case INDEX_op_or_i64:
     case INDEX_op_xor_i64:
+    case INDEX_op_shl_i64:
+    case INDEX_op_shr_i64:
+    case INDEX_op_sar_i64:
+    case INDEX_op_rotl_i64:
+    case INDEX_op_rotr_i64:
         return 64;
 #endif
     default:
@@ -205,6 +215,58 @@ static TCGArg do_constant_folding_2(int op, TCGArg x, TCGArg y)
     CASE_OP_32_64(xor):
         return x ^ y;
 
+    case INDEX_op_shl_i32:
+        return (uint32_t)x << (uint32_t)y;
+
+#if TCG_TARGET_REG_BITS == 64
+    case INDEX_op_shl_i64:
+        return (uint64_t)x << (uint64_t)y;
+#endif
+
+    case INDEX_op_shr_i32:
+        return (uint32_t)x >> (uint32_t)y;
+
+#if TCG_TARGET_REG_BITS == 64
+    case INDEX_op_shr_i64:
+        return (uint64_t)x >> (uint64_t)y;
+#endif
+
+    case INDEX_op_sar_i32:
+        return (int32_t)x >> (int32_t)y;
+
+#if TCG_TARGET_REG_BITS == 64
+    case INDEX_op_sar_i64:
+        return (int64_t)x >> (int64_t)y;
+#endif
+
+    case INDEX_op_rotr_i32:
+#if TCG_TARGET_REG_BITS == 64
+        x &= 0xffffffff;
+        y &= 0xffffffff;
+#endif
+        x = (x << (32 - y)) | (x >> y);
+        return x;
+
+#if TCG_TARGET_REG_BITS == 64
+    case INDEX_op_rotr_i64:
+        x = (x << (64 - y)) | (x >> y);
+        return x;
+#endif
+
+    case INDEX_op_rotl_i32:
+#if TCG_TARGET_REG_BITS == 64
+        x &= 0xffffffff;
+        y &= 0xffffffff;
+#endif
+        x = (x << y) | (x >> (32 - y));
+        return x;
+
+#if TCG_TARGET_REG_BITS == 64
+    case INDEX_op_rotl_i64:
+        x = (x << y) | (x >> (64 - y));
+        return x;
+#endif
+
     default:
         fprintf(stderr,
                 "Unrecognized operation %d in do_constant_folding.\n", op);
@@ -278,6 +340,11 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
         switch (op) {
         CASE_OP_32_64(add):
         CASE_OP_32_64(sub):
+        CASE_OP_32_64(shl):
+        CASE_OP_32_64(shr):
+        CASE_OP_32_64(sar):
+        CASE_OP_32_64(rotl):
+        CASE_OP_32_64(rotr):
             if (temps[args[1]].state == TCG_TEMP_CONST) {
                 /* Proceed with possible constant folding. */
                 break;
@@ -363,6 +430,11 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
         CASE_OP_32_64(or):
         CASE_OP_32_64(and):
         CASE_OP_32_64(xor):
+        CASE_OP_32_64(shl):
+        CASE_OP_32_64(shr):
+        CASE_OP_32_64(sar):
+        CASE_OP_32_64(rotl):
+        CASE_OP_32_64(rotr):
             if (temps[args[1]].state == TCG_TEMP_CONST
                 && temps[args[2]].state == TCG_TEMP_CONST) {
                 gen_opc_buf[op_index] = op_to_movi(op);