tests/micropython: Remove big ints dependence for viper boundary tests.

This commit provides an implementation for viper boundary tests that can
work even without big int support.

Since it uses a fixed-size buffer to hold values to work with, this
should work on any platform as long as its integers are at least 32 bits
wide, regardless its configuration on how big integers can get.

Signed-off-by: Alessandro Gatti <a.gatti@frob.it>

tests/micropython/viper_ptr16_store_boundary.py

@@ -15,6 +15,23 @@ SIZE = 2
 MASK = (1 << (8 * SIZE)) - 1
 
 
+next_int = 1
+test_buffer = bytearray(SIZE)
+
+
+def next_value() -> uint:
+    global next_int
+    global test_buffer
+    for index in range(1, SIZE):
+        test_buffer[index - 1] = test_buffer[index]
+    test_buffer[SIZE - 1] = next_int
+    next_int += 1
+    output = 0
+    for byte in test_buffer:
+        output = (output << 8) | byte
+    return output & MASK
+
+
 @micropython.viper
 def set_index(dest: ptr16, i: int, val: uint):
     saved = dest
@@ -27,8 +44,6 @@ def get_index(src, i):
 
 
 buffer = bytearray(((1 << max(BIT_THRESHOLDS) + 1) // 1024) * 1024)
-next = 1
-val = 0
 for bit in BIT_THRESHOLDS:
     print("---", bit)
     pre, idx, post = (
@@ -36,22 +51,10 @@ for bit in BIT_THRESHOLDS:
         (((1 << bit) - (1 * SIZE)) // SIZE),
         ((1 << bit) // SIZE),
     )
-    val = (val << 8) + next
-    next += 1
-    set_index(buffer, pre, val & MASK)
-    val = (val << 8) + next
-    next += 1
-    set_index(buffer, idx, val & MASK)
-    val = (val << 8) + next
-    next += 1
-    set_index(buffer, post, val & MASK)
-    val = (val << 8) + next
-    next += 1
+    set_index(buffer, pre, next_value())
+    set_index(buffer, idx, next_value())
+    set_index(buffer, post, next_value())
     print(hex(get_index(buffer, pre)), hex(get_index(buffer, idx)), hex(get_index(buffer, post)))
-    exec(SET_TEMPLATE.format(off=pre, val=val & MASK))
-    val = (val << 8) + next
-    next += 1
-    exec(SET_TEMPLATE.format(off=idx, val=val & MASK))
-    val = (val << 8) + next
-    next += 1
-    exec(SET_TEMPLATE.format(off=post, val=val & MASK))
+    exec(SET_TEMPLATE.format(off=pre, val=next_value()))
+    exec(SET_TEMPLATE.format(off=idx, val=next_value()))
+    exec(SET_TEMPLATE.format(off=post, val=next_value()))

tests/micropython/viper_ptr32_store_boundary.py

@@ -14,6 +14,22 @@ BIT_THRESHOLDS = (5, 8, 11, 12)
 SIZE = 4
 MASK = (1 << (8 * SIZE)) - 1
 
+next_int = 1
+test_buffer = bytearray(SIZE)
+
+
+def next_value() -> uint:
+    global next_int
+    global test_buffer
+    for index in range(1, SIZE):
+        test_buffer[index - 1] = test_buffer[index]
+    test_buffer[SIZE - 1] = next_int
+    next_int += 1
+    output = 0
+    for byte in test_buffer:
+        output = (output << 8) | byte
+    return output & MASK
+
 
 @micropython.viper
 def set_index(dest: ptr32, i: int, val: uint):
@@ -32,8 +48,6 @@ def get_index(src, i):
 
 
 buffer = bytearray(((1 << max(BIT_THRESHOLDS) + 1) // 1024) * 1024)
-next = 1
-val = 0
 for bit in BIT_THRESHOLDS:
     print("---", bit)
     pre, idx, post = (
@@ -41,22 +55,10 @@ for bit in BIT_THRESHOLDS:
         (((1 << bit) - (1 * SIZE)) // SIZE),
         ((1 << bit) // SIZE),
     )
-    val = (val << 8) + next
-    next += 1
-    set_index(buffer, pre, val & MASK)
-    val = (val << 8) + next
-    next += 1
-    set_index(buffer, idx, val & MASK)
-    val = (val << 8) + next
-    next += 1
-    set_index(buffer, post, val & MASK)
-    val = (val << 8) + next
-    next += 1
+    set_index(buffer, pre, next_value())
+    set_index(buffer, idx, next_value())
+    set_index(buffer, post, next_value())
     print(hex(get_index(buffer, pre)), hex(get_index(buffer, idx)), hex(get_index(buffer, post)))
-    exec(SET_TEMPLATE.format(off=pre, val=val & MASK))
-    val = (val << 8) + next
-    next += 1
-    exec(SET_TEMPLATE.format(off=idx, val=val & MASK))
-    val = (val << 8) + next
-    next += 1
-    exec(SET_TEMPLATE.format(off=post, val=val & MASK))
+    exec(SET_TEMPLATE.format(off=pre, val=next_value()))
+    exec(SET_TEMPLATE.format(off=idx, val=next_value()))
+    exec(SET_TEMPLATE.format(off=post, val=next_value()))

tests/micropython/viper_ptr8_store_boundary.py

@@ -14,6 +14,22 @@ BIT_THRESHOLDS = (5, 8, 11, 12)
 SIZE = 1
 MASK = (1 << (8 * SIZE)) - 1
 
+next_int = 1
+test_buffer = bytearray(SIZE)
+
+
+def next_value() -> uint:
+    global next_int
+    global test_buffer
+    for index in range(1, SIZE):
+        test_buffer[index - 1] = test_buffer[index]
+    test_buffer[SIZE - 1] = next_int
+    next_int += 1
+    output = 0
+    for byte in test_buffer:
+        output = (output << 8) | byte
+    return output & MASK
+
 
 @micropython.viper
 def set_index(dest: ptr8, i: int, val: uint):
@@ -27,27 +43,13 @@ def get_index(src: ptr8, i: int):
 
 
 buffer = bytearray(((1 << max(BIT_THRESHOLDS) + 1) // 1024) * 1024)
-next = 1
-val = 0
 for bit in BIT_THRESHOLDS:
     print("---", bit)
     pre, idx, post = (((1 << bit) - (2 * SIZE)), ((1 << bit) - (1 * SIZE)), (1 << bit))
-    val = (val << 8) + next
-    next += 1
-    set_index(buffer, pre, val & MASK)
-    val = (val << 8) + next
-    next += 1
-    set_index(buffer, idx, val & MASK)
-    val = (val << 8) + next
-    next += 1
-    set_index(buffer, post, val & MASK)
-    val = (val << 8) + next
-    next += 1
+    set_index(buffer, pre, next_value())
+    set_index(buffer, idx, next_value())
+    set_index(buffer, post, next_value())
     print(hex(get_index(buffer, pre)), hex(get_index(buffer, idx)), hex(get_index(buffer, post)))
-    exec(SET_TEMPLATE.format(off=pre, val=val & MASK))
-    val = (val << 8) + next
-    next += 1
-    exec(SET_TEMPLATE.format(off=idx, val=val & MASK))
-    val = (val << 8) + next
-    next += 1
-    exec(SET_TEMPLATE.format(off=post, val=val & MASK))
+    exec(SET_TEMPLATE.format(off=pre, val=next_value()))
+    exec(SET_TEMPLATE.format(off=idx, val=next_value()))
+    exec(SET_TEMPLATE.format(off=post, val=next_value()))