--- old/src/java.base/share/classes/jdk/internal/util/ArraysSupport.java	2018-06-18 13:46:24.611000000 -0700
+++ new/src/java.base/share/classes/jdk/internal/util/ArraysSupport.java	2018-06-18 13:46:24.250000000 -0700
@@ -165,6 +165,8 @@
                                boolean[] b,
                                int length) {
         int i = 0;
+        if (a[i] != b[i])
+            return i;
         if (length > 7) {
             i = vectorizedMismatch(
                     a, Unsafe.ARRAY_BOOLEAN_BASE_OFFSET,
@@ -185,6 +187,8 @@
                                boolean[] b, int bFromIndex,
                                int length) {
         int i = 0;
+        if (a[i] != b[i])
+            return i;
         if (length > 7) {
             int aOffset = Unsafe.ARRAY_BOOLEAN_BASE_OFFSET + aFromIndex;
             int bOffset = Unsafe.ARRAY_BOOLEAN_BASE_OFFSET + bFromIndex;
@@ -227,6 +231,8 @@
         // assert length <= b.length
 
         int i = 0;
+        if (a[i] != b[i])
+            return i;
         if (length > 7) {
             i = vectorizedMismatch(
                     a, Unsafe.ARRAY_BYTE_BASE_OFFSET,
@@ -274,6 +280,8 @@
         // assert length >= 0
 
         int i = 0;
+        if (a[i] != b[i])
+            return i;
         if (length > 7) {
             int aOffset = Unsafe.ARRAY_BYTE_BASE_OFFSET + aFromIndex;
             int bOffset = Unsafe.ARRAY_BYTE_BASE_OFFSET + bFromIndex;
@@ -299,6 +307,8 @@
                                char[] b,
                                int length) {
         int i = 0;
+        if (a[i] != b[i])
+            return i;
         if (length > 3) {
             i = vectorizedMismatch(
                     a, Unsafe.ARRAY_CHAR_BASE_OFFSET,
@@ -319,6 +329,8 @@
                                char[] b, int bFromIndex,
                                int length) {
         int i = 0;
+        if (a[i] != b[i])
+            return i;
         if (length > 3) {
             int aOffset = Unsafe.ARRAY_CHAR_BASE_OFFSET + (aFromIndex << LOG2_ARRAY_CHAR_INDEX_SCALE);
             int bOffset = Unsafe.ARRAY_CHAR_BASE_OFFSET + (bFromIndex << LOG2_ARRAY_CHAR_INDEX_SCALE);
@@ -344,6 +356,8 @@
                                short[] b,
                                int length) {
         int i = 0;
+        if (a[i] != b[i])
+            return i;
         if (length > 3) {
             i = vectorizedMismatch(
                     a, Unsafe.ARRAY_SHORT_BASE_OFFSET,
@@ -364,6 +378,8 @@
                                short[] b, int bFromIndex,
                                int length) {
         int i = 0;
+        if (a[i] != b[i])
+            return i;
         if (length > 3) {
             int aOffset = Unsafe.ARRAY_SHORT_BASE_OFFSET + (aFromIndex << LOG2_ARRAY_SHORT_INDEX_SCALE);
             int bOffset = Unsafe.ARRAY_SHORT_BASE_OFFSET + (bFromIndex << LOG2_ARRAY_SHORT_INDEX_SCALE);
@@ -389,6 +405,8 @@
                                int[] b,
                                int length) {
         int i = 0;
+        if (a[i] != b[i])
+            return i;
         if (length > 1) {
             i = vectorizedMismatch(
                     a, Unsafe.ARRAY_INT_BASE_OFFSET,
@@ -409,6 +427,8 @@
                                int[] b, int bFromIndex,
                                int length) {
         int i = 0;
+        if (a[i] != b[i])
+            return i;
         if (length > 1) {
             int aOffset = Unsafe.ARRAY_INT_BASE_OFFSET + (aFromIndex << LOG2_ARRAY_INT_INDEX_SCALE);
             int bOffset = Unsafe.ARRAY_INT_BASE_OFFSET + (bFromIndex << LOG2_ARRAY_INT_INDEX_SCALE);
@@ -440,6 +460,8 @@
                                float[] b, int bFromIndex,
                                int length) {
         int i = 0;
+        if (a[i] != b[i])
+            return i;
         if (length > 1) {
             int aOffset = Unsafe.ARRAY_FLOAT_BASE_OFFSET + (aFromIndex << LOG2_ARRAY_FLOAT_INDEX_SCALE);
             int bOffset = Unsafe.ARRAY_FLOAT_BASE_OFFSET + (bFromIndex << LOG2_ARRAY_FLOAT_INDEX_SCALE);