From 7659157f1b926321530a44ce8fc7a39a0360a08e Mon Sep 17 00:00:00 2001
From: Aaron Watry <awatry@gmail.com>
Date: Thu, 15 Aug 2013 19:21:07 +0000
Subject: [PATCH] Add hadd builtin

(x + y) >> 1 gets changed to:
(x>>1) + (y>>1) + (x&y&1)

Saves us having to do any llvm assembly and overflow checking in the addition.

Reviewed-by: Tom Stellard <thomas.stellard@amd.com>
llvm-svn: 188476
---
 libclc/generic/include/clc/clc.h            | 1 +
 libclc/generic/include/clc/integer/hadd.h   | 2 ++
 libclc/generic/include/clc/integer/hadd.inc | 1 +
 libclc/generic/lib/SOURCES                  | 1 +
 libclc/generic/lib/integer/hadd.cl          | 4 ++++
 libclc/generic/lib/integer/hadd.inc         | 6 ++++++
 6 files changed, 15 insertions(+)
 create mode 100644 libclc/generic/include/clc/integer/hadd.h
 create mode 100644 libclc/generic/include/clc/integer/hadd.inc
 create mode 100644 libclc/generic/lib/integer/hadd.cl
 create mode 100644 libclc/generic/lib/integer/hadd.inc

diff --git a/libclc/generic/include/clc/clc.h b/libclc/generic/include/clc/clc.h
index b9062455c41f..38f71dbdee0c 100644
--- a/libclc/generic/include/clc/clc.h
+++ b/libclc/generic/include/clc/clc.h
@@ -65,6 +65,7 @@
 #include <clc/integer/abs_diff.h>
 #include <clc/integer/add_sat.h>
 #include <clc/integer/clz.h>
+#include <clc/integer/hadd.h>
 #include <clc/integer/mad24.h>
 #include <clc/integer/mul24.h>
 #include <clc/integer/rotate.h>
diff --git a/libclc/generic/include/clc/integer/hadd.h b/libclc/generic/include/clc/integer/hadd.h
new file mode 100644
index 000000000000..37304e26cc2d
--- /dev/null
+++ b/libclc/generic/include/clc/integer/hadd.h
@@ -0,0 +1,2 @@
+#define __CLC_BODY <clc/integer/hadd.inc>
+#include <clc/integer/gentype.inc>
diff --git a/libclc/generic/include/clc/integer/hadd.inc b/libclc/generic/include/clc/integer/hadd.inc
new file mode 100644
index 000000000000..f698989cef20
--- /dev/null
+++ b/libclc/generic/include/clc/integer/hadd.inc
@@ -0,0 +1 @@
+_CLC_OVERLOAD _CLC_DECL __CLC_GENTYPE hadd(__CLC_GENTYPE x, __CLC_GENTYPE y);
diff --git a/libclc/generic/lib/SOURCES b/libclc/generic/lib/SOURCES
index 9ac08bd9d241..e936fbc6d94b 100644
--- a/libclc/generic/lib/SOURCES
+++ b/libclc/generic/lib/SOURCES
@@ -11,6 +11,7 @@ integer/add_sat_impl.ll
 integer/clz.cl
 integer/clz_if.ll
 integer/clz_impl.ll
+integer/hadd.cl
 integer/mad24.cl
 integer/mul24.cl
 integer/rotate.cl
diff --git a/libclc/generic/lib/integer/hadd.cl b/libclc/generic/lib/integer/hadd.cl
new file mode 100644
index 000000000000..749026e5a8ad
--- /dev/null
+++ b/libclc/generic/lib/integer/hadd.cl
@@ -0,0 +1,4 @@
+#include <clc/clc.h>
+
+#define __CLC_BODY <hadd.inc>
+#include <clc/integer/gentype.inc>
diff --git a/libclc/generic/lib/integer/hadd.inc b/libclc/generic/lib/integer/hadd.inc
new file mode 100644
index 000000000000..ea59d9bd7db5
--- /dev/null
+++ b/libclc/generic/lib/integer/hadd.inc
@@ -0,0 +1,6 @@
+//hadd = (x+y)>>1
+//This can be simplified to x>>1 + y>>1 + (1 if both x and y have the 1s bit set)
+//This saves us having to do any checks for overflow in the addition sum
+_CLC_OVERLOAD _CLC_DEF __CLC_GENTYPE hadd(__CLC_GENTYPE x, __CLC_GENTYPE y) {
+    return (x>>(__CLC_GENTYPE)1)+(y>>(__CLC_GENTYPE)1)+(x&y&(__CLC_GENTYPE)1);
+}
-- 
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