[FRONTEND] Semantic analysis refactor (#491)

Moved dispatch.cc to semantic.py (@ptillet)
Integer signedness analysis was moved from C++ to python (@daadaada)
Cleaner frontend types (@daadaada)
Moved SSA construction to a separate object (@ptillet)


Co-authored-by: Yan Da <dyanab@connect.ust.hk>

python/test/unit/runtime/test_cache.py

@@ -1,4 +1,5 @@
 import os
+import re
 import shutil
 
 import pytest
@@ -102,3 +103,30 @@ def test_specialize(mode):
     for i in [1, 2, 4, 8, 16, 32]:
         function[(1,)](x, i, BLOCK=512)
     assert counter == target
+
+
+@pytest.mark.parametrize("value, value_type", [
+    (-1, 'int32'), (0, 'int32'), (1, None), (-2**31, 'int32'), (2**31 - 1, 'int32'),
+    (2**32, 'int64'), (2**63 - 1, 'int64'), (-2**63, 'int64'),
+    (2**31, 'uint32'), (2**32 - 1, 'uint32'), (2**63, 'uint64'), (2**64 - 1, 'uint64')
+])
+def test_value_specialization(value: int, value_type: str, device='cuda') -> None:
+
+    @triton.jit
+    def kernel(VALUE, X):
+        pass
+
+    cache_str = None
+
+    def get_cache_str(*args, **kwargs):
+        nonlocal cache_str
+        cache_str = kwargs['key'].split('-')
+    triton.code_gen.JITFunction.cache_hook = get_cache_str
+    reset_tmp_dir()
+    x = torch.tensor([3.14159], device='cuda')
+    kernel[(1, )](value, x)
+    triton.code_gen.JITFunction.cache_hook = None
+
+    cache_str_match = re.match(r'_(\w+)\[multipleof\(\d+\)]_float32\*\[multipleof\(16\)\]', cache_str[-1])
+    spec_type = None if cache_str_match is None else cache_str_match.group(1)
+    assert spec_type == value_type