[Backend Tester] Report quantization and lowering times (#12838)

Track and report the time taken to quantize and lower in the backend
test flow. Include this information in the generated report for each
test case.

Example output (from testing add operator):
Test ID | Test Case | Backend | Flow | Result | Quantize Time (s) |
Lowering Time (s)
-- | -- | -- | -- | -- | -- | --
test_add_dtype_float32_coreml | test_add_dtype | coreml | coreml |
Success (Delegated) |   | 0.69
test_add_dtype_float32_coreml_static_int8 | test_add_dtype | coreml |
coreml_static_int8 | Success (Delegated) | 8.73 | 0.88

Author: GregoryComer

backends/test/suite/reporting.py

@@ -1,6 +1,7 @@
 import csv
 from collections import Counter
 from dataclasses import dataclass
+from datetime import timedelta
 from enum import IntEnum
 from functools import reduce
 from typing import TextIO
@@ -108,6 +109,12 @@ class TestCaseSummary:
     a single output tensor.
     """
 
+    quantize_time: timedelta | None = None
+    """ The total runtime of the quantization stage, or none, if the test did not run the quantize stage. """
+
+    lower_time: timedelta | None = None
+    """ The total runtime of the to_edge_transform_and_lower stage, or none, if the test did not run the quantize stage. """
+
 
 class TestSessionState:
     test_case_summaries: list[TestCaseSummary]
@@ -190,6 +197,8 @@ def generate_csv_report(summary: RunSummary, output: TextIO):
         "Backend",
         "Flow",
         "Result",
+        "Quantize Time (s)",
+        "Lowering Time (s)",
     ]
 
     # Tests can have custom parameters. We'll want to report them here, so we need
@@ -230,6 +239,12 @@ def generate_csv_report(summary: RunSummary, output: TextIO):
             "Backend": record.backend,
             "Flow": record.flow,
             "Result": record.result.display_name(),
+            "Quantize Time (s)": (
+                record.quantize_time.total_seconds() if record.quantize_time else None
+            ),
+            "Lowering Time (s)": (
+                record.lower_time.total_seconds() if record.lower_time else None
+            ),
         }
         if record.params is not None:
             row.update({k.capitalize(): v for k, v in record.params.items()})

backends/test/suite/runner.py

@@ -1,8 +1,10 @@
 import argparse
 import importlib
 import re
+import time
 import unittest
 
+from datetime import timedelta
 from typing import Any
 
 import torch
@@ -44,6 +46,7 @@ def run_test(  # noqa: C901
     """
 
     error_statistics: list[ErrorStatistics] = []
+    extra_stats = {}
 
     # Helper method to construct the summary.
     def build_result(
@@ -58,6 +61,7 @@ def build_result(
             result=result,
             error=error,
             tensor_error_statistics=error_statistics,
+            **extra_stats,
         )
 
     # Ensure the model can run in eager mode.
@@ -72,11 +76,16 @@ def build_result(
         return build_result(TestResult.UNKNOWN_FAIL, e)
 
     if flow.quantize:
+        start_time = time.perf_counter()
         try:
             tester.quantize(
                 flow.quantize_stage_factory() if flow.quantize_stage_factory else None
             )
+            elapsed = time.perf_counter() - start_time
+            extra_stats["quantize_time"] = timedelta(seconds=elapsed)
         except Exception as e:
+            elapsed = time.perf_counter() - start_time
+            extra_stats["quantize_time"] = timedelta(seconds=elapsed)
             return build_result(TestResult.QUANTIZE_FAIL, e)
 
     try:
@@ -87,9 +96,14 @@ def build_result(
     except Exception as e:
         return build_result(TestResult.EXPORT_FAIL, e)
 
+    lower_start_time = time.perf_counter()
     try:
         tester.to_edge_transform_and_lower()
+        elapsed = time.perf_counter() - lower_start_time
+        extra_stats["lower_time"] = timedelta(seconds=elapsed)
     except Exception as e:
+        elapsed = time.perf_counter() - lower_start_time
+        extra_stats["lower_time"] = timedelta(seconds=elapsed)
         return build_result(TestResult.LOWER_FAIL, e)
 
     is_delegated = any(
@@ -185,6 +199,7 @@ def parse_args():
         "--report",
         nargs="?",
         help="A file to write the test report to, in CSV format.",
+        default="backend_test_report.csv",
     )
     return parser.parse_args()