Modify input limits for apply_scale_32

Aligns with change in specification, as the limit to value being between
(-1 << shift-2) and (1 << shift-2) was overly constraining.

Signed-off-by: Eric Kunze <eric.kunze@arm.com>
Change-Id: I72cc5743344d4036920c3df366e0a3930701a0cb

2 files changed, 8 insertions, 9 deletions

diff --git a/reference_model/src/quant_util.h b/reference_model/src/quant_util.h
index 3b7674d..2e5c2e5 100644
--- a/reference_model/src/quant_util.h
+++ b/reference_model/src/quant_util.h
@@ -55,14 +55,13 @@ public:
                 "apply_scale_32(): shift value should stay within [2, 62] but is " + std::to_string(shift);
             throw desc;
         }
-        int64_t low_val = -1L << (shift-2);
-        int64_t high_val = 1L << (shift-2);
+        int64_t low_val  = -1L << (shift - 1);
+        int64_t high_val = 1L << (shift - 1);
         if (value < low_val || value >= high_val)
         {
-            std::string desc =
-                "apply_scale_32(): value should stay within [" +
-                std::to_string(low_val) + ", " + std::to_string(high_val-1) +
-                "] but is " + std::to_string(value) + " using shift of " + std::to_string(shift);
+            std::string desc = "apply_scale_32(): value should stay within [" + std::to_string(low_val) + ", " +
+                               std::to_string(high_val - 1) + "] but is " + std::to_string(value) + " using shift of " +
+                               std::to_string(shift);
             throw desc;
         }
         int64_t round = 1L << (shift - 1);
diff --git a/verif/generator/tosa_test_gen.py b/verif/generator/tosa_test_gen.py
index b0e7c8c..583e1ed 100644
--- a/verif/generator/tosa_test_gen.py
+++ b/verif/generator/tosa_test_gen.py
@@ -1653,13 +1653,13 @@ class TosaTestGen:
             multiplier_arr[i], shift_arr[i] = TosaQuantGen.computeMultiplierAndShift(
                 scale_arr[i], scale32
             )
-            min_shift_value_arr[i] = -1 << (shift_arr[i] - 2)
-            max_shift_value_arr[i] = (1 << (shift_arr[i] - 2)) - 1
+            min_shift_value_arr[i] = -1 << (shift_arr[i] - 1)
+            max_shift_value_arr[i] = (1 << (shift_arr[i] - 1)) - 1
 
         # print('multiplier {} shift {} inzp {} outzp {}'.format(multiplier_arr, shift_arr, input_zp, output_zp))
         if scale32 and error_name is None:
             # Make sure random values are within apply_scale_32 specification
-            # REQUIRES(value >= (-1<<(shift-2)) && value < (1<<(shift-2))
+            # REQUIRES(value >= (-1<<(shift-1)) && value < (1<<(shift-1))
             assert val.placeholderFilename
             values = np.load(
                 os.path.join(self.basePath, self.testPath, val.placeholderFilename)