Support 16-bit Rescale

Signed-off-by: Kevin Cheng <kevin.cheng@arm.com>
Change-Id: Ifc80b83c1abcd08e1b7f8e50f647b74c861bc933

1 files changed, 15 insertions, 2 deletions

diff --git a/reference_model/src/quant_util.h b/reference_model/src/quant_util.h
index 1784493..f07dd10 100644
--- a/reference_model/src/quant_util.h
+++ b/reference_model/src/quant_util.h
@@ -61,6 +61,19 @@ public:
                    "apply_scale_32() error: scaled result exceed int32 numeric range");
         return static_cast<int32_t>(result);
     }
+
+    static int32_t apply_scale_16(int64_t value, int16_t multiplier, int32_t shift)
+    {
+        ASSERT_MSG(multiplier >= 0, "apply_scale_16() error: multiplier should >= 0 but is %d", multiplier);
+        ASSERT_MSG(value >= -(static_cast<int64_t>(1) << 47) && value < (static_cast<int64_t>(1) << 47),
+                   "apply_scale_16() error: value should be within [-(1^47), 1^47]");
+        int64_t round  = 1L << (shift - 1);
+        int64_t result = value * (int64_t)multiplier + round;
+        result         = result >> shift;
+        ASSERT_MSG(result >= -(1L << 31) && result < (1L << 31),
+                   "apply_scale_16() error: scaled result exceed int32 numeric range");
+        return static_cast<int32_t>(result);
+    }
 };
 
 class TypeChecker
@@ -68,8 +81,8 @@ class TypeChecker
 public:
     static bool is_integer(DType dtype)
     {
-        if (dtype == DType_INT4 || dtype == DType_INT8 || dtype == DType_UINT8 ||
-            dtype == DType_INT16 || dtype == DType_INT32 || dtype == DType_INT48)
+        if (dtype == DType_INT4 || dtype == DType_INT8 || dtype == DType_UINT8 || dtype == DType_INT16 ||
+            dtype == DType_INT32 || dtype == DType_INT48)
         {
             return true;
         }