Added cbrt() and exp2() functions in math module (#1594)

Author: harshsingh-24

integration_tests/CMakeLists.txt

@@ -331,6 +331,7 @@ RUN(NAME test_builtin_divmod LABELS cpython llvm c)
 RUN(NAME test_builtin_sum    LABELS cpython llvm c)
 RUN(NAME test_math1          LABELS cpython llvm c)
 RUN(NAME test_math_02        LABELS cpython llvm)
+RUN(NAME test_math_03        LABELS llvm)               #1595: TODO: Test using CPython (3.11 recommended)
 RUN(NAME test_pass_compare   LABELS cpython llvm c)
 RUN(NAME test_c_interop_01   LABELS cpython llvm c)
 RUN(NAME test_c_interop_02   LABELS cpython llvm c

integration_tests/test_math.py

@@ -60,7 +60,6 @@ def test_exp():
     i = exp(2.34)
     assert abs(i - 10.381236562731843) < eps
 
-
 def test_pow():
     eps: f64
     eps = 1e-12

integration_tests/test_math_03.py

@@ -0,0 +1,21 @@
+from math import (cbrt, exp2)
+from ltypes import f64
+
+eps: f64
+eps = 1e-12
+
+def test_exp2():
+    i: f64
+    i = exp2(4.3)
+    assert abs(i - 19.698310613518657) < eps
+
+def test_cbrt():
+    eps: f64 = 1e-12
+    assert abs(cbrt(124.0) - 4.986630952238646) < eps
+    assert abs(cbrt(39.0) - 3.3912114430141664) < eps
+
+def check():
+    test_cbrt()
+    test_exp2()
+
+check()

src/runtime/math.py

@@ -465,6 +465,12 @@ def exp(x: f64) -> f64:
     """
     return e**x
 
+def exp2(x: f64) -> f64:
+    """
+    Return `2` raised to the power `x`.
+    """
+    return f64((2.0)**x)
+
 
 def mod(a: i32, b: i32) -> i32:
     """
@@ -540,8 +546,17 @@ def trunc(x: f32) -> i32:
         return ceil(x)
 
 def sqrt(x: f64) -> f64:
+    """
+    Returns square root of a number x
+    """
     return x**(1/2)
 
+def cbrt(x: f64) -> f64:
+    """
+    Returns cube root of a number x
+    """
+    return x**(1/3)
+
 @ccall
 def _lfortran_dsin(x: f64) -> f64:
     pass