saturated conversion of native GPU data type, larger to narrower

This patch supports saturated conversion of
native GPU data type (char/short/int/float),
from a larger-range data type to a narrower-range data type.
For instance,  convert_uchar_sat(int)

Several test cases are in this patch.

v2: add uint->int, int->uint

Signed-off-by: Homer Hsing <homer.xing@intel.com>
Reviewed-by: "Yang, Rong R" <rong.r.yang@intel.com>

2 files changed, 72 insertions, 0 deletions

diff --git a/utests/CMakeLists.txt b/utests/CMakeLists.txt
index f18bd46f..31b85e38 100644
--- a/utests/CMakeLists.txt
+++ b/utests/CMakeLists.txt
@@ -126,6 +126,7 @@ set (utests_sources
   builtin_num_groups.cpp
   builtin_local_id.cpp
   builtin_acos_asin.cpp
+  builtin_convert_sat.cpp
   runtime_createcontext.cpp
   runtime_null_kernel_arg.cpp
   runtime_event.cpp
diff --git a/utests/builtin_convert_sat.cpp b/utests/builtin_convert_sat.cpp
new file mode 100644
index 00000000..e16ce16a
--- /dev/null
+++ b/utests/builtin_convert_sat.cpp
@@ -0,0 +1,71 @@
+#include <cstdint>
+#include "utest_helper.hpp"
+
+typedef unsigned char uchar;
+typedef unsigned short ushort;
+
+int64_t my_rand(void) {
+  int64_t x = rand() - RAND_MAX/2;
+  int64_t y = rand() - RAND_MAX/2;
+  return x * y;
+}
+
+#define DEF(DST_TYPE, SRC_TYPE, DST_MIN, DST_MAX) \
+void builtin_convert_ ## SRC_TYPE ## _to_ ## DST_TYPE ## _sat(void) \
+{ \
+  const int n = 128; \
+  OCL_CREATE_KERNEL_FROM_FILE("builtin_convert_sat", "builtin_convert_" # SRC_TYPE "_to_" # DST_TYPE "_sat"); \
+  OCL_CREATE_BUFFER(buf[0], 0, n * sizeof(SRC_TYPE), NULL); \
+  OCL_CREATE_BUFFER(buf[1], 0, n * sizeof(DST_TYPE), NULL); \
+  OCL_SET_ARG(0, sizeof(cl_mem), &buf[0]); \
+  OCL_SET_ARG(1, sizeof(cl_mem), &buf[1]); \
+  globals[0] = n; \
+  locals[0] = 16; \
+  OCL_MAP_BUFFER(0); \
+  for (int i = 0; i < n; i++) \
+    ((SRC_TYPE *)buf_data[0])[i] = my_rand(); \
+  OCL_UNMAP_BUFFER(0); \
+  OCL_NDRANGE(1); \
+  OCL_MAP_BUFFER(0); \
+  OCL_MAP_BUFFER(1); \
+  for (int i = 0; i < n; i++) { \
+    SRC_TYPE src = ((SRC_TYPE *)buf_data[0])[i]; \
+    DST_TYPE dst; \
+    if ((double)src > (double)DST_MAX) \
+      dst = DST_MAX; \
+    else if ((double)src < (double)DST_MIN) \
+      dst = DST_MIN; \
+    else \
+      dst = src; \
+    OCL_ASSERT(((DST_TYPE *)buf_data[1])[i] == dst); \
+  } \
+  OCL_UNMAP_BUFFER(0); \
+  OCL_UNMAP_BUFFER(1); \
+} \
+MAKE_UTEST_FROM_FUNCTION(builtin_convert_ ## SRC_TYPE ## _to_ ## DST_TYPE ## _sat);
+
+DEF(char, uchar, -128, 127);
+DEF(char, short, -128, 127);
+DEF(char, ushort, -128, 127);
+DEF(char, int, -128, 127);
+DEF(char, uint, -128, 127);
+DEF(char, float, -128, 127);
+DEF(uchar, char, 0, 255);
+DEF(uchar, short, 0, 255);
+DEF(uchar, ushort, 0, 255);
+DEF(uchar, int, 0, 255);
+DEF(uchar, uint, 0, 255);
+DEF(uchar, float, 0, 255);
+DEF(short, ushort, -32768, 32767);
+DEF(short, int, -32768, 32767);
+DEF(short, uint, -32768, 32767);
+DEF(short, float, -32768, 32767);
+DEF(ushort, short, 0, 65535);
+DEF(ushort, int, 0, 65535);
+DEF(ushort, uint, 0, 65535);
+DEF(ushort, float, 0, 65535);
+DEF(int, uint, -0x7FFFFFFF-1, 0x7FFFFFFF);
+DEF(int, float, -0x7FFFFFFF-1, 0x7FFFFFFF);
+DEF(uint, int, 0, 0xffffffffu);
+DEF(uint, float, 0, 0xffffffffu);
+#undef DEF