From: Jacob Lifshay <programmerjake@gmail.com>
Date: Fri, 6 Oct 2023 22:21:07 +0000 (-0700)
Subject: rename divmod algorithm -> divmod_shift_sub in prep for adding divmod based on Knuth... 
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=cddc275b380ad182aaac0fa681617d02c52155e9;p=openpower-isa.git

rename divmod algorithm -> divmod_shift_sub in prep for adding divmod based on Knuth's Algorithm D
---

diff --git a/src/openpower/decoder/isa/test_caller_svp64_powmod.py b/src/openpower/decoder/isa/test_caller_svp64_powmod.py
index 055b40d4..1ea02a23 100644
--- a/src/openpower/decoder/isa/test_caller_svp64_powmod.py
+++ b/src/openpower/decoder/isa/test_caller_svp64_powmod.py
@@ -15,18 +15,19 @@ import unittest
 from functools import lru_cache
 import os
 from openpower.test.bigint.powmod import (
-    PowModCases, python_divmod_algorithm, python_powmod_256_algorithm)
+    PowModCases, python_divmod_shift_sub_algorithm,
+    python_powmod_256_algorithm)
 from openpower.test.runner import TestRunnerBase
 
 
 class TestPythonAlgorithms(unittest.TestCase):
-    def test_python_divmod_algorithm(self):
+    def test_python_divmod_shift_sub_algorithm(self):
         for n, d in PowModCases.divmod_512x256_to_256x256_test_inputs():
             q, r = divmod(n, d)
             with self.subTest(n=f"{n:#_x}", d=f"{d:#_x}",
                               q=f"{q:#_x}", r=f"{r:#_x}"):
                 log_regex = n == 2 ** 511 - 1 and d == 2 ** 256 - 1
-                out_q, out_r = python_divmod_algorithm(
+                out_q, out_r = python_divmod_shift_sub_algorithm(
                     n, d, log_regex=log_regex)
                 with self.subTest(out_q=f"{out_q:#_x}", out_r=f"{out_r:#_x}"):
                     self.assertEqual(out_q, q)
diff --git a/src/openpower/test/bigint/powmod.py b/src/openpower/test/bigint/powmod.py
index 4f2f2d93..f17139b0 100644
--- a/src/openpower/test/bigint/powmod.py
+++ b/src/openpower/test/bigint/powmod.py
@@ -123,7 +123,7 @@ def python_mul_algorithm2(a, b):
     return y
 
 
-DIVMOD_512x256_TO_256x256_ASM = (
+DIVMOD_SHIFT_SUB_512x256_TO_256x256_ASM = (
     # extremely slow and simplistic shift and subtract algorithm.
     # a future task is to rewrite to use Knuth's Algorithm D,
     # which is generally an order of magnitude faster
@@ -228,7 +228,7 @@ class _DivModRegsRegexLogger:
         log("DIVMOD REGEX:", "".join(segments))
 
 
-def python_divmod_algorithm(n, d, width=256, log_regex=False):
+def python_divmod_shift_sub_algorithm(n, d, width=256, log_regex=False):
     assert n >= 0 and d > 0 and width > 0 and n < (d << width), "invalid input"
     do_log = _DivModRegsRegexLogger(enabled=log_regex).log
 
@@ -332,7 +332,7 @@ POWMOD_256_ASM = (
     "sv.ld *14, -144(1)",  # restore all callee-save registers
     "bclr 20, 0, 0 # blr",
     *MUL_256_X_256_TO_512_ASM,
-    *DIVMOD_512x256_TO_256x256_ASM,
+    *DIVMOD_SHIFT_SUB_512x256_TO_256x256_ASM,
 )
 
 
@@ -409,7 +409,7 @@ class PowModCases(TestAccumulatorBase):
                 n -= d << 256
             yield (n, d)
 
-    def case_divmod_512x256_to_256x256(self):
+    def case_divmod_shift_sub_512x256_to_256x256(self):
         for n, d in self.divmod_512x256_to_256x256_test_inputs():
             q, r = divmod(n, d)
             with self.subTest(n=f"{n:#_x}", d=f"{d:#_x}",
@@ -434,7 +434,8 @@ class PowModCases(TestAccumulatorBase):
                     # write r in LE order to regs 8-11
                     e.intregs[8 + i] = (r >> (64 * i)) % 2**64
 
-                self.call_case(DIVMOD_512x256_TO_256x256_ASM, e, initial_regs)
+                self.call_case(
+                    DIVMOD_SHIFT_SUB_512x256_TO_256x256_ASM, e, initial_regs)
 
     @staticmethod
     def powmod_256_test_inputs():