From b3061c38ef984418e266c6f74b366a7e953840a5 Mon Sep 17 00:00:00 2001
From: Dmitry Selyutin <dmitry.selyutin@3mdeb.com>
Date: Wed, 25 Aug 2021 14:44:23 +0000
Subject: [PATCH] pywriter: support RANGE helper

---
 src/openpower/decoder/helpers.py         | 10 ++++++++++
 src/openpower/decoder/pseudo/parser.py   | 14 +++-----------
 src/openpower/decoder/pseudo/pywriter.py |  1 +
 3 files changed, 14 insertions(+), 11 deletions(-)

diff --git a/src/openpower/decoder/helpers.py b/src/openpower/decoder/helpers.py
index 87b71d99..09f2324a 100644
--- a/src/openpower/decoder/helpers.py
+++ b/src/openpower/decoder/helpers.py
@@ -22,6 +22,16 @@ Links:
 """
 
 
+def RANGE(start, end):
+    if start > end:
+        # auto-subtract-one (sigh) due to python range
+        end -= 1
+    else:
+        # auto-add-one (sigh) due to python range
+        end += 1
+    return range(start, end)
+
+
 def exts(value, bits):
     sign = 1 << (bits - 1)
     return (value & (sign - 1)) - (value & sign)
diff --git a/src/openpower/decoder/pseudo/parser.py b/src/openpower/decoder/pseudo/parser.py
index 72ce61e4..03d0fd5e 100644
--- a/src/openpower/decoder/pseudo/parser.py
+++ b/src/openpower/decoder/pseudo/parser.py
@@ -495,20 +495,12 @@ class PowerParser:
         p[0] = ast.Break()
 
     def p_for_stmt(self, p):
-        """for_stmt : FOR atom EQ test TO test COLON suite
-                    | DO atom EQ test TO test COLON suite
+        """for_stmt : FOR atom EQ comparison TO comparison COLON suite
+                    | DO atom EQ comparison TO comparison COLON suite
         """
         start = p[4]
         end = p[6]
-        if start.value > end.value:  # start greater than end, must go -ve
-            # auto-subtract-one (sigh) due to python range
-            end = ast.BinOp(p[6], ast.Add(), ast.Constant(-1))
-            arange = [start, end, ast.Constant(-1)]
-        else:
-            # auto-add-one (sigh) due to python range
-            end = ast.BinOp(p[6], ast.Add(), ast.Constant(1))
-            arange = [start, end]
-        it = ast.Call(ast.Name("range", ast.Load()), arange, [])
+        it = ast.Call(ast.Name("RANGE", ast.Load()), (start, end), [])
         p[0] = ast.For(p[2], it, p[8], [])
 
     def p_while_stmt(self, p):
diff --git a/src/openpower/decoder/pseudo/pywriter.py b/src/openpower/decoder/pseudo/pywriter.py
index efca91c9..1387e890 100644
--- a/src/openpower/decoder/pseudo/pywriter.py
+++ b/src/openpower/decoder/pseudo/pywriter.py
@@ -26,6 +26,7 @@ from openpower.decoder.helpers import (EXTS, EXTS64, EXTZ64, ROTL64, ROTL32,
                                  trunc_divs, trunc_rems, MULS, DIVS, MODS,
                                  EXTS128, undefined,
                                  bitrev, SHL64,
+                                 RANGE,
                                 )
 from openpower.decoder.selectable_int import SelectableInt
 from openpower.decoder.selectable_int import selectconcat as concat
-- 
2.30.2