From 354686be7657d153808b63813ca54b47bd5e0ca0 Mon Sep 17 00:00:00 2001
From: Peter Collingbourne <peter@pcc.me.uk>
Date: Tue, 21 Aug 2012 10:48:35 +0000
Subject: [PATCH] Add rsqrt builtin.  Based on patch by Cassie Epps!

llvm-svn: 162274
---
 libclc/generic/include/clc/clc.h        | 1 +
 libclc/generic/include/clc/math/rsqrt.h | 1 +
 libclc/test/rsqrt.cl                    | 6 ++++++
 3 files changed, 8 insertions(+)
 create mode 100644 libclc/generic/include/clc/math/rsqrt.h
 create mode 100644 libclc/test/rsqrt.cl

diff --git a/libclc/generic/include/clc/clc.h b/libclc/generic/include/clc/clc.h
index 4f497601b3d0..565b505add67 100644
--- a/libclc/generic/include/clc/clc.h
+++ b/libclc/generic/include/clc/clc.h
@@ -53,6 +53,7 @@
 #include <clc/math/native_log2.h>
 #include <clc/math/native_sin.h>
 #include <clc/math/native_sqrt.h>
+#include <clc/math/rsqrt.h>
 
 /* 6.11.3 Integer Functions */
 #include <clc/integer/abs.h>
diff --git a/libclc/generic/include/clc/math/rsqrt.h b/libclc/generic/include/clc/math/rsqrt.h
new file mode 100644
index 000000000000..8fd2cbff9cb3
--- /dev/null
+++ b/libclc/generic/include/clc/math/rsqrt.h
@@ -0,0 +1 @@
+#define rsqrt(x) (1.f/sqrt(x))
diff --git a/libclc/test/rsqrt.cl b/libclc/test/rsqrt.cl
new file mode 100644
index 000000000000..13ad216b79f4
--- /dev/null
+++ b/libclc/test/rsqrt.cl
@@ -0,0 +1,6 @@
+#pragma OPENCL EXTENSION cl_khr_fp64 : enable
+
+__kernel void foo(float4 *x, double4 *y) {
+  x[1] = rsqrt(x[0]);
+  y[1] = rsqrt(y[0]);
+}