4 files changed, 74 insertions, 19 deletions

diff --git a/tests/custom/00_syntax/10_numeric_literals b/tests/custom/00_syntax/10_numeric_literals
index 3e367d0..7aa49b6 100644
--- a/tests/custom/00_syntax/10_numeric_literals
+++ b/tests/custom/00_syntax/10_numeric_literals
@@ -12,7 +12,7 @@ Special values: Infinity, Infinity, NaN, NaN
 Minimum values: -9223372036854775808, -1.79769e+308
 Maximum values: 9223372036854775807, 1.79769e+308
 Minimum truncation: -9223372036854775808, -Infinity
-Maximum truncation: 9223372036854775807, Infinity
+Maximum truncation: 18446744073709551615, Infinity
 -- End --
 
 -- Testcase --
@@ -21,6 +21,6 @@ Float literals: {{ 10. }}, {{ 10.3 }}, {{ 123.456e-67 }}, {{ 0x10.1 }}
 Special values: {{ Infinity }}, {{ 1 / 0 }}, {{ NaN }}, {{ "x" / 1 }}
 Minimum values: {{ -9223372036854775808 }}, {{ -1.7976931348623158e+308 }}
 Maximum values: {{ 9223372036854775807 }}, {{ 1.7976931348623158e+308 }}
-Minimum truncation: {{ -10000000000000000000 }}, {{ -1.0e309 }}
-Maximum truncation: {{ 10000000000000000000 }}, {{ 1.0e309 }}
+Minimum truncation: {{ -100000000000000000000 }}, {{ -1.0e309 }}
+Maximum truncation: {{ 100000000000000000000 }}, {{ 1.0e309 }}
 -- End --
diff --git a/tests/custom/01_arithmetic/02_modulo b/tests/custom/01_arithmetic/02_modulo
index 244d624..c011e04 100644
--- a/tests/custom/01_arithmetic/02_modulo
+++ b/tests/custom/01_arithmetic/02_modulo
@@ -1,32 +1,31 @@
-The utpl language supports modulo divisions, however they're only defined
-for integer values.
+The ucode language supports modulo divisions.
 
 -- Expect stdout --
 If both operands are integers or convertible to integers,
-the modulo division yields the remainder:
+the modulo division yields the remaining integer value:
 10 % 4 = 2
 "10" % 4 = 2
 10 % "4" = 2
 "10" % "4" = 2
 
 If either operand is a double value, the modulo operation
-yields NaN:
-10.0 % 4 = NaN
-10 % 4.0 = NaN
-"10.0" % 4 = NaN
+yields the remaining value as calculated by fmod(3):
+10.2 % 4 = 2.2
+10 % 4.3 = 1.4
+"10.4" % 4 = 2.4
 -- End --
 
 -- Testcase --
 If both operands are integers or convertible to integers,
-the modulo division yields the remainder:
+the modulo division yields the remaining integer value:
 10 % 4 = {{ 10 % 4 }}
 "10" % 4 = {{ "10" % 4 }}
 10 % "4" = {{ 10 % 4 }}
 "10" % "4" = {{ "10" % "4" }}
 
 If either operand is a double value, the modulo operation
-yields NaN:
-10.0 % 4 = {{ 10.0 % 4 }}
-10 % 4.0 = {{ 10 % 4.0 }}
-"10.0" % 4 = {{ "10.0" % 4 }}
+yields the remaining value as calculated by fmod(3):
+10.2 % 4 = {{ 10.2 % 4 }}
+10 % 4.3 = {{ 10 % 4.3 }}
+"10.4" % 4 = {{ "10.4" % 4 }}
 -- End --
diff --git a/tests/custom/01_arithmetic/03_bitwise b/tests/custom/01_arithmetic/03_bitwise
index faf4ffd..c481b3e 100644
--- a/tests/custom/01_arithmetic/03_bitwise
+++ b/tests/custom/01_arithmetic/03_bitwise
@@ -1,5 +1,7 @@
-Utpl implements C-style bitwise operations. One detail is that these operations
-coerce their operands to signed 64bit integer values internally.
+Ucode implements C-style bitwise operations. One detail is that these operations
+coerce their operands to 64bit integer values internally. If both operands are
+positive, unsigned 64bit semantics are used. If one of the operands is negative,
+both are converted to signed 64bit numbers.
 
 -- Expect stdout --
 Left shift:
@@ -23,8 +25,8 @@ Bitwise or:
 120.3 | 54.3 = 126
 
 Complement:
-~0 = -1
-~10.4 = -11
+~0 = 18446744073709551615
+~10.4 = 18446744073709551605
 -- End --
 
 -- Testcase --
diff --git a/tests/custom/01_arithmetic/05_overflow b/tests/custom/01_arithmetic/05_overflow
new file mode 100644
index 0000000..8c2f214
--- /dev/null
+++ b/tests/custom/01_arithmetic/05_overflow
@@ -0,0 +1,54 @@
+For integers, the ucode VM tries to perform unsigned 64bit arithmetic internally
+if both operands are positive or if the result is guaranteed to be positive.
+
+In all other cases, calculations are performed using signed 64bit arithmetic
+with wrap arounds using twos-complement representation.
+
+Due to this, the minimum and maximum representable values depend on the values
+of the involved operands.
+
+-- Testcase --
+Unsigned additions roll over back to zero:
+{{ 18446744073709551615 + 1 }}
+
+Unsigned multiplications roll over back to zero:
+{{ 9223372036854775808 * 2 }}
+
+Signed additions roll over at INT64_MIN/INT64_MAX:
+{{ -9223372036854775808 + -1 }}
+
+Signed multiplications roll over back to INT64_MIN:
+{{ 18446744073709551615 * -1 }}
+
+Multiplicating two negative operands yields an unsigned result.
+{{ -9223372036854775807 * -2 }}
+
+Signed calculations yielding positive results are promoted to unsigned.
+{{ -9223372036854775808 + 9223372036854775808 + -9223372036854775807 * -2 }}
+
+Substractions roll over to INT64_MAX on underflow:
+{{ 0 - 9223372036854775809 }}
+-- End --
+
+-- Expect stdout --
+Unsigned additions roll over back to zero:
+0
+
+Unsigned multiplications roll over back to zero:
+0
+
+Signed additions roll over at INT64_MIN/INT64_MAX:
+9223372036854775807
+
+Signed multiplications roll over back to INT64_MIN:
+-9223372036854775807
+
+Multiplicating two negative operands yields an unsigned result.
+18446744073709551614
+
+Signed calculations yielding positive results are promoted to unsigned.
+18446744073709551614
+
+Substractions roll over to INT64_MAX on underflow:
+9223372036854775807
+-- End --