Adjust pseudocode types to account for zero point

When reading tensor values with zero point, the returned value
has one more bit than the original to account for zero point.

Update cases of apply_clip to properly represent the types
involved.

Change-Id: I60c17b1b244c34b4f04f042807936ae0f282ce93

1 files changed, 22 insertions, 16 deletions

diff --git a/chapters/introduction.adoc b/chapters/introduction.adoc
index 3257ab0..7039e27 100644
--- a/chapters/introduction.adoc
+++ b/chapters/introduction.adoc
@@ -197,14 +197,20 @@ The padding array represents the before and after pair for each dimension.
 ....
 assert((pad ==  NULL) || size(pad) == 2 * size(shape));
 out_t tensor_read<in_t>(in_t *address, dim_t shape, dim_t index, in_t zero_point=0, dim_t pad=NULL) {
-  assert(in_t == int8_t || zero_point == 0)
-  unsigned offset = 0;
-  for (i = 0; i < rank(shape); i++)
-    if (index[i] < 0) { assert(pad && pad[2 * i] + index[i] >= 0); return 0; }
-    if (index[i] >= shape[i]) { assert(pad && index[i] < shape[i] + pad[2 * i + 1]); return 0; }
-    offset = offset * shape[i] + index[i]
-  }
-  return address[offset] - zero_point;
+    assert(in_t == int8_t || zero_point == 0)
+    unsigned offset = 0;
+    for (i = 0; i < rank(shape); i++) {
+        if (index[i] < 0) {
+            assert(pad && pad[2 * i] + index[i] >= 0);
+            return 0;
+        }
+        if (index[i] >= shape[i]) {
+            assert(pad && index[i] < shape[i] + pad[2 * i + 1]);
+            return 0;
+        }
+        offset = offset * shape[i] + index[i];
+    }
+    return address[offset] - zero_point;
 }
 ....
 
@@ -212,12 +218,12 @@ out_t tensor_read<in_t>(in_t *address, dim_t shape, dim_t index, in_t zero_point
 
 ....
 tensor_write<type>(<type> *address, dim_t shape, dim_t index, <type> value) {
-  unsigned offset = 0;
-  for (i = 0; i < rank(shape); i++)
-    assert (index[i] >= 0 && index[i] < shape[i]);
-    offset = offset * shape[i] + index[i];
-  }
-  address[offset] = value;
+    unsigned offset = 0;
+    for (i = 0; i < rank(shape); i++) {
+        assert (index[i] >= 0 && index[i] < shape[i]);
+        offset = offset * shape[i] + index[i];
+    }
+    address[offset] = value;
 }
 ....
 
@@ -346,7 +352,7 @@ All table lookups are based on the following reference lookup function that take
 ....
 int32_t apply_lookup(int16_t *table, int32_t value)
 {
-    int16_t clipped_value = apply_clip<int16_t>(value, -32768, +32767);
+    int16_t clipped_value = (int16_t)apply_clip<int32_t>(value, -32768, +32767);
     int32_t index = (clipped_value + 32768) >> 7;
     int32_t fraction = clipped_value & 0x7f;
     int16_t base = table[index];
@@ -364,7 +370,7 @@ void generate_lookup_table(int16_t *table, int32_t (*reference)(int32_t))
 {
     for (int i = -256; i <= 256; i++) {
         int32_t value = (*reference)(i);
-        table[i + 256] = apply_clip<int16_t>(value, -32768, +32767)
+        table[i + 256] = (int16_t)apply_clip<int32_t>(value, -32768, +32767)
     }
 }
 ....