Merge pull request #2501 from Shaikh-Ubaid/fix_const_step_in_loop

Fix const step in loop

Author: certik

integration_tests/CMakeLists.txt

@@ -509,6 +509,7 @@ RUN(NAME loop_04             LABELS cpython llvm c)
 RUN(NAME loop_05             LABELS cpython llvm c)
 RUN(NAME loop_06             LABELS cpython llvm c NOFAST)
 RUN(NAME loop_07             LABELS cpython llvm c)
+RUN(NAME loop_08             LABELS cpython llvm c)
 RUN(NAME if_01               LABELS cpython llvm c wasm wasm_x86 wasm_x64)
 RUN(NAME if_02               LABELS cpython llvm c wasm wasm_x86 wasm_x64)
 RUN(NAME if_03    FAIL       LABELS cpython llvm c NOFAST)

integration_tests/loop_08.py

@@ -0,0 +1,13 @@
+from lpython import i32, Const
+
+def main0():
+    i: i32
+    n: Const[i32] = 10
+    M2: Const[i32] = 2
+    y: i32 = 0
+    for i in range(0, n, M2):  # each M2 block in A cols and B rows  # !!!!!!!!!!!!!!
+        y = y + 2
+    print(y)
+    assert(y == 10)
+
+main0()

src/libasr/pass/pass_utils.cpp

@@ -893,7 +893,8 @@ namespace LCompilers {
                 if( comp == -1 ) {
                     int increment;
                     bool not_constant_inc = false;
-                    if (!ASRUtils::is_integer(*ASRUtils::expr_type(c))) {
+                    if (!ASRUtils::is_integer(*ASRUtils::type_get_past_const(
+                            ASRUtils::expr_type(c)))) {
                         throw LCompilersException("Do loop increment type should be an integer");
                     }
                     if (c->type == ASR::exprType::IntegerConstant) {

src/lpython/semantics/python_ast_to_asr.cpp

@@ -5301,7 +5301,8 @@ class BodyVisitor : public CommonVisitor<BodyVisitor> {
         head.m_start = loop_start;
         head.m_increment = inc;
 
-        if( !ASR::is_a<ASR::Integer_t>(*ASRUtils::expr_type(inc)) ) {
+        if( !ASR::is_a<ASR::Integer_t>(*ASRUtils::type_get_past_const(
+                ASRUtils::expr_type(inc))) ) {
             throw SemanticError("For loop increment type should be Integer.", loc);
         }
         ASR::expr_t *inc_value = ASRUtils::expr_value(inc);