Implement symbolic sign function (#2715)

* Implement symbolic sign function and added tests for the same.

Author: anutosh491

integration_tests/symbolics_06.py

@@ -1,4 +1,4 @@
-from sympy import Symbol, sin, cos, exp, log, Abs, pi, diff
+from sympy import Symbol, sin, cos, exp, log, Abs, pi, diff, sign
 from lpython import S
 
 def test_elementary_functions():
@@ -25,6 +25,13 @@ def test_elementary_functions():
     assert(Abs(S(10)) == S(10))
     assert(Abs(S(-1)*x) == Abs(x))
 
+    # test sign
+    assert(sign(S(-10)) == S(-1))
+    assert(sign(S(0)) == S(0))
+    assert(sign(S(10)) == S(1))
+    assert(sign(S(2)* x) == sign(x))
+    assert(sign(S(-1)* x) == S(-1) * sign(x))
+
     # test composite functions
     a: S = exp(x)
     b: S = sin(a)

src/libasr/pass/intrinsic_function_registry.h

@@ -154,6 +154,7 @@ inline std::string get_intrinsic_name(int x) {
         INTRINSIC_NAME_CASE(SymbolicLog)
         INTRINSIC_NAME_CASE(SymbolicExp)
         INTRINSIC_NAME_CASE(SymbolicAbs)
+        INTRINSIC_NAME_CASE(SymbolicSign)
         INTRINSIC_NAME_CASE(SymbolicHasSymbolQ)
         INTRINSIC_NAME_CASE(SymbolicAddQ)
         INTRINSIC_NAME_CASE(SymbolicMulQ)
@@ -448,6 +449,8 @@ namespace IntrinsicElementalFunctionRegistry {
             {nullptr, &SymbolicExp::verify_args}},
         {static_cast<int64_t>(IntrinsicElementalFunctions::SymbolicAbs),
             {nullptr, &SymbolicAbs::verify_args}},
+        {static_cast<int64_t>(IntrinsicElementalFunctions::SymbolicSign),
+            {nullptr, &SymbolicSign::verify_args}},
         {static_cast<int64_t>(IntrinsicElementalFunctions::SymbolicHasSymbolQ),
             {nullptr, &SymbolicHasSymbolQ::verify_args}},
         {static_cast<int64_t>(IntrinsicElementalFunctions::SymbolicAddQ),
@@ -739,6 +742,8 @@ namespace IntrinsicElementalFunctionRegistry {
             "SymbolicExp"},
         {static_cast<int64_t>(IntrinsicElementalFunctions::SymbolicAbs),
             "SymbolicAbs"},
+        {static_cast<int64_t>(IntrinsicElementalFunctions::SymbolicSign),
+            "SymbolicSign"},
         {static_cast<int64_t>(IntrinsicElementalFunctions::SymbolicHasSymbolQ),
             "SymbolicHasSymbolQ"},
         {static_cast<int64_t>(IntrinsicElementalFunctions::SymbolicAddQ),
@@ -900,6 +905,7 @@ namespace IntrinsicElementalFunctionRegistry {
                 {"SymbolicLog", {&SymbolicLog::create_SymbolicLog, &SymbolicLog::eval_SymbolicLog}},
                 {"SymbolicExp", {&SymbolicExp::create_SymbolicExp, &SymbolicExp::eval_SymbolicExp}},
                 {"SymbolicAbs", {&SymbolicAbs::create_SymbolicAbs, &SymbolicAbs::eval_SymbolicAbs}},
+                {"SymbolicSign", {&SymbolicSign::create_SymbolicSign, &SymbolicSign::eval_SymbolicSign}},
                 {"has", {&SymbolicHasSymbolQ::create_SymbolicHasSymbolQ, &SymbolicHasSymbolQ::eval_SymbolicHasSymbolQ}},
                 {"AddQ", {&SymbolicAddQ::create_SymbolicAddQ, &SymbolicAddQ::eval_SymbolicAddQ}},
                 {"MulQ", {&SymbolicMulQ::create_SymbolicMulQ, &SymbolicMulQ::eval_SymbolicMulQ}},

src/libasr/pass/intrinsic_functions.h

@@ -155,6 +155,7 @@ enum class IntrinsicElementalFunctions : int64_t {
     SymbolicLog,
     SymbolicExp,
     SymbolicAbs,
+    SymbolicSign,
     SymbolicHasSymbolQ,
     SymbolicAddQ,
     SymbolicMulQ,
@@ -5968,6 +5969,7 @@ create_symbolic_unary_macro(SymbolicCos)
 create_symbolic_unary_macro(SymbolicLog)
 create_symbolic_unary_macro(SymbolicExp)
 create_symbolic_unary_macro(SymbolicAbs)
+create_symbolic_unary_macro(SymbolicSign)
 create_symbolic_unary_macro(SymbolicExpand)
 
 } // namespace LCompilers::ASRUtils

src/libasr/pass/replace_symbolic.cpp

@@ -477,6 +477,7 @@ class ReplaceSymbolicVisitor : public PassUtils::PassVisitor<ReplaceSymbolicVisi
             BASIC_UNARYOP(Log, log)
             BASIC_UNARYOP(Exp, exp)
             BASIC_UNARYOP(Abs, abs)
+            BASIC_UNARYOP(Sign, sign)
             BASIC_UNARYOP(Expand, expand)
             BASIC_TERNARYOP(Subs, subs2)
             case LCompilers::ASRUtils::IntrinsicElementalFunctions::SymbolicGetArgument: {

src/lpython/semantics/python_ast_to_asr.cpp

@@ -7677,7 +7677,7 @@ we will have to use something else.
             };
             if (symbolic_attributes.find(at->m_attr) != symbolic_attributes.end()){
                 std::set<std::string> symbolic_functions = {
-                    "sin", "cos", "log", "exp", "Abs", "Symbol"
+                    "sin", "cos", "log", "exp", "Abs", "sign", "Symbol"
                 };
                 if (AST::is_a<AST::Attribute_t>(*call->m_func)) {
                     visit_Call(*call);
@@ -7809,7 +7809,7 @@ we will have to use something else.
                 "sum" // For sum called over lists
             };
             std::set<std::string> symbolic_functions = {
-                "sin", "cos", "log", "exp", "Abs"
+                "sin", "cos", "log", "exp", "Abs", "sign"
             };
             if ((symbolic_functions.find(call_name) != symbolic_functions.end()) &&
                 imported_functions[call_name] == "sympy"){