libm: arm: add arm specific sqrt and sqrtf

Add arm specific optimized sqrt and sqrtf.

Change-Id: I8ea417fc98a800c8cf4f47a0c6668c51d927b1dc

libm/arm/e_sqrt.S

@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2013-2014, NVIDIA Corporation.  All rights reserved.
+ * Johnny Qiu <joqiu@nvidia.com>
+ * Shu Zhang <chazhang@nvidia.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ *       copyright notice, this list of conditions and the following
+ *       disclaimer in the documentation and/or other materials provided
+ *       with the distribution.
+ *     * Neither the name of The Linux Foundation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
+ * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
+ * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <float.h>
+#include <private/bionic_asm.h>
+
+ENTRY(sqrt)
+    vmov.f64    d0, r0, r1
+    vsqrt.f64   d0, d0
+    vmov.f64    r0, r1, d0
+    bx          lr
+END(sqrt)
+
+#if LDBL_MANT_DIG == 53
+    .weak       sqrtl
+    .equ        sqrtl, sqrt
+#endif