libm: sqrt and sqrtf via ARM vsqrt instruction.cm-10.1.0-RC3

Optimized sqrt and sqrtf for arm by using hardware
opcode for sqrt rather than generic slow portable
code.

Change-Id: I9888d58547bcfca7dfc1400d3e7e222599167249

3 files changed, 81 insertions, 6 deletions

diff --git a/libm/Android.mk b/libm/Android.mk
index 1f76366..67c3cb2 100644
--- a/libm/Android.mk
+++ b/libm/Android.mk
@@ -53,7 +53,6 @@ libm_common_src_files:= \
 	src/e_scalbf.c \
 	src/e_sinh.c \
 	src/e_sinhf.c \
-	src/e_sqrt.c \
 	src/k_cos.c \
 	src/k_cosf.c \
 	src/k_rem_pio2.c \
@@ -157,8 +156,7 @@ ifeq ($(TARGET_ARCH),arm)
 	src/e_ldexpf.c \
 	src/s_scalbln.c \
 	src/s_scalbn.c \
-	src/s_scalbnf.c \
-	src/e_sqrtf.c
+	src/s_scalbnf.c
 
   ifeq ($(ARCH_ARM_HAVE_NEON),true)
     libm_common_src_files += \
@@ -168,12 +166,16 @@ ifeq ($(TARGET_ARCH),arm)
   ifeq ($(TARGET_USE_KRAIT_BIONIC_OPTIMIZATION),true)
     libm_common_src_files += \
 	  arm/s_cos.S \
-	  arm/s_sin.S
+	  arm/s_sin.S \
+	  arm/e_sqrtf.S \
+	  arm/e_sqrt.S
     libm_common_cflags += -DKRAIT_NEON_OPTIMIZATION -fno-if-conversion
   else
     libm_common_src_files += \
 	  src/s_cos.c \
-	  src/s_sin.c
+	  src/s_sin.c \
+	  src/e_sqrtf.c \
+	  src/e_sqrt.c
   endif
 
   libm_common_includes = $(LOCAL_PATH)/arm
@@ -181,7 +183,8 @@ ifeq ($(TARGET_ARCH),arm)
 else
   libm_common_src_files += \
 	src/s_cos.c \
-	src/s_sin.c
+	src/s_sin.c \
+	src/e_sqrt.c
 endif
 
 ifeq ($(TARGET_OS)-$(TARGET_ARCH),linux-x86)
diff --git a/libm/arm/e_sqrt.S b/libm/arm/e_sqrt.S
new file mode 100644
index 0000000..28dc647
--- /dev/null
+++ b/libm/arm/e_sqrt.S
@@ -0,0 +1,36 @@
+@ Copyright (c) 2013, The Linux Foundation. All rights reserved.
+@
+@ 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 <machine/cpu-features.h>
+#include <machine/asm.h>
+
+ENTRY(sqrt)
+    vmov.f64    d0, r0, r1
+    vsqrt.f64   d0, d0
+    vmov.f64    r0, r1, d0
+    bx          lr
+END(sqrt)
diff --git a/libm/arm/e_sqrtf.S b/libm/arm/e_sqrtf.S
new file mode 100644
index 0000000..4f2e4a0
--- /dev/null
+++ b/libm/arm/e_sqrtf.S
@@ -0,0 +1,36 @@
+@ Copyright (c) 2013, The Linux Foundation. All rights reserved.
+@
+@ 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 <machine/cpu-features.h>
+#include <machine/asm.h>
+
+ENTRY(sqrtf)
+    vmov.f32    s0, r0
+    vsqrt.f32   s0, s0
+    vmov.f32    r0, s0
+    bx          lr
+END(sqrtf)