Evaluating the values of CCL lists for different scenarios

QEfficient/utils/check_ccl_specializations.py

@@ -103,6 +103,8 @@ def automatic_ccl_generation(
                 max_elements=constants.CCL_MAX_ELEMENTS_LISTS,
                 last_value=prefill_last,
             )
+        # Set the last element in prefill_list to maximum possible input prompt to support all input lengths
+        prefill_list[-1] = mapped_cl
 
         return prefill_list, decode_list, mapped_cl
 
@@ -126,36 +128,78 @@ def automatic_ccl_generation(
         logger.warning("prefill_seq_len cannot be less than 1!")
 
 
+def validate_ccl_lists(ccl_prefill, ccl_decode, ctx_len, prefill_seq_len):
+    # Check CCL values are not negative and more than the CCL minimum context length = constants.CCL_MIN_CTX_LEN
+    if ccl_prefill:
+        ccl_prefill = [x if x >= constants.CCL_MIN_CTX_LEN else constants.CCL_MIN_CTX_LEN for x in ccl_prefill]
+    if ccl_decode:
+        ccl_decode = [x if x >= constants.CCL_MIN_CTX_LEN else constants.CCL_MIN_CTX_LEN for x in ccl_decode]
+
+    # Check the last element of ccl_prefill and ccl_decode to make sure it's not less than ctx_len
+    if ccl_prefill[-1] < ctx_len - 1:
+        ccl_prefill.append(ctx_len)
+    if ccl_decode[-1] < ctx_len:
+        ccl_decode.append(ctx_len)
+
+    if prefill_seq_len == 1:
+        # both prefill and decode ccl can share the same specializations since prefill_seq_len=1. So, a sorted union of both lists can be used for both of them.
+        ccl_union_all = sorted(set([min(x, ctx_len) for x in ccl_prefill + ccl_decode]))
+        ccl_prefill = ccl_union_all
+        ccl_decode = ccl_union_all
+    else:
+        # Sort ccl_prefill and ccl_decode lists and make sure they don't have repeated elements and also are less than ctx_len
+        if ccl_prefill:
+            ccl_prefill = sorted({min(x, ctx_len) for x in (ccl_prefill)})
+        if ccl_decode:
+            ccl_decode = sorted({min(x, ctx_len) for x in (ccl_decode)})
+
+        # Handling the common values between ccl_prefill and ccl_decode. The elements of these two lists should be unique (COMPILER)
+        tmp_prefill = ccl_prefill
+        ccl_prefill = []
+        for val in tmp_prefill:
+            while val in ccl_decode or val in ccl_prefill:
+                val -= 1
+                if val < 0:
+                    break  # Prevent negative values
+            if val >= 0:
+                ccl_prefill.append(val)
+        ccl_prefill.sort()
+
+    return ccl_prefill, ccl_decode
+
+
 def process_ccl_specializations(ccl_prefill, ccl_decode, ctx_len, prefill_seq_len):
+    """
+    This function evaluates the values of CCL lists based on three inputs:
+      - ccl_prefill: optional [list]
+      - ccl_decode: optional [list]
+      - ccl_enabled: optional [bool]
+
+    Conditions to handle:
+      1) ccl_prefill AND ccl_decode AND ccl_enabled == True
+      2) ccl_prefill AND ccl_decode (ccl_enabled not provided)
+      3) ccl_prefill ONLY AND ccl_enabled == True and ccl_decode not provided
+      4) ccl_decode ONLY AND ccl_enabled == True and ccl_prefill not provided
+      5) ccl_prefill ONLY (ccl_enabled and ccl_decode are not provided)
+      6) ccl_decode ONLY (ccl_enabled and ccl_prefill are not provided)
+      7) ccl_enabled == True (no ccl_prefill, no ccl_decode) -> Automatic CCL lists generation
+    """
     # Automatic CCL generation: If both ccl_prefill and ccl_decode are None
-    if ccl_prefill is None and ccl_decode is None:
+    # Condition #7
+    if not ccl_prefill and not ccl_decode:
         # Generate optimized context length lists for prefill and decode based on ctx_len
         # Due to compiler limitations, ccl_prefill and ccl_decode must have distinct values
         ccl_prefill, ccl_decode, ctx_len = automatic_ccl_generation(ctx_len, prefill_seq_len)
-    else:
-        if prefill_seq_len == 1:
-            if ccl_prefill is not None and ccl_decode is not None:
-                # both prefill and decode ccl can share the same specializations since prefill_seq_len=1. So, a sorted union of both lists can be used for both of them.
-                ccl_union_all = sorted(set([min(x, ctx_len) for x in ccl_prefill + ccl_decode]))
-                ccl_prefill = ccl_union_all
-                ccl_decode = ccl_union_all
-        else:
-            if ccl_prefill:
-                ccl_prefill = sorted({min(x, ctx_len) for x in (ccl_prefill)})
-            if ccl_decode:
-                ccl_decode = sorted({min(x, ctx_len) for x in (ccl_decode)})
-
-            if ccl_prefill is not None and ccl_decode is not None:
-                tmp_prefill = ccl_prefill
-                ccl_prefill = []
-                for val in tmp_prefill:
-                    while val in ccl_decode or val in ccl_prefill:
-                        val -= 1
-                        if val < 0:
-                            break  # Prevent negative values
-                    if val >= 0:
-                        ccl_prefill.append(val)
-                ccl_prefill.sort()
+
+    # One of ccl lists is [] or None -> replace it with [ctx_len] -> CCL lists have to have a value when CCL is enabled
+    # Condition #3, #4, #5, and #6
+    elif not ccl_prefill or not ccl_decode:
+        # Initial setting and will be checked with edge cases later
+        ccl_prefill = ccl_prefill if ccl_prefill else [ctx_len]
+        ccl_decode = ccl_decode if ccl_decode else [ctx_len]
+
+    # Verifying ccl_prefill and ccl_decode values for all conditions
+    ccl_prefill, ccl_decode = validate_ccl_lists(ccl_prefill, ccl_decode, ctx_len, prefill_seq_len)
 
     logger.info("CCL Configuration:")
     logger.info(f"  - Prefill context lengths: {ccl_prefill}")

QEfficient/utils/constants.py

@@ -177,6 +177,7 @@ def get_models_dir():
 # Limitation in the maximum number of elements in comp_ctx_lengths_decode and comp_ctx_lengths_prefill lists during automatic lists generation process.
 CCL_MAX_ELEMENTS_LISTS = 5
 CCL_START_CTX_LEN = 4096
+CCL_MIN_CTX_LEN = 1024
 
 # used for gpt-oss prefill-only model Q-blocking
 GPT_OSS_PREFILL_Q_BLOCK_SIZE = 256