feat: add llvm implementation of quick_sort

Author: HarshitaKalani

pydatastructs/linear_data_structures/_backend/cpp/algorithms/algorithms.cpp

@@ -6,6 +6,8 @@
 static PyMethodDef algorithms_PyMethodDef[] = {
     {"quick_sort", (PyCFunction) quick_sort,
      METH_VARARGS | METH_KEYWORDS, ""},
+    {"quick_sort_llvm",  (PyCFunction)quick_sort_llvm,
+     METH_VARARGS | METH_KEYWORDS, ""},
     {"bubble_sort", (PyCFunction) bubble_sort,
      METH_VARARGS | METH_KEYWORDS, ""},
     {"bubble_sort_llvm",  (PyCFunction)bubble_sort_llvm,

pydatastructs/linear_data_structures/_backend/cpp/algorithms/llvm_algorithms.py

@@ -41,6 +41,14 @@ def get_bubble_sort_ptr(dtype: str) -> int:
 
     return _materialize(dtype)
 
+
+def get_quick_sort_ptr(dtype: str) -> int:
+    dtype = dtype.lower().strip()
+    if dtype not in _SUPPORTED:
+        raise ValueError(f"Unsupported dtype '{dtype}'. Supported: {list(_SUPPORTED)}")
+
+    return _materialize_quick(dtype)
+
 def _build_bubble_sort_ir(dtype: str) -> str:
     if dtype not in _SUPPORTED:
         raise ValueError(f"Unsupported dtype '{dtype}'. Supported: {list(_SUPPORTED)}")
@@ -131,6 +139,134 @@ def _build_bubble_sort_ir(dtype: str) -> str:
 
     return str(mod)
 
+
+def _build_quick_sort_ir(dtype: str) -> str:
+    if dtype not in _SUPPORTED:
+        raise ValueError(f"Unsupported dtype '{dtype}'. Supported: {list(_SUPPORTED)}")
+
+    T, _ = _SUPPORTED[dtype]
+    i32 = ir.IntType(32)
+    i64 = ir.IntType(64)
+
+    mod = ir.Module(name=f"quick_sort_{dtype}_module")
+    fn_name = f"quick_sort_{dtype}"
+
+    # void quick_sort(T* arr, int32 low, int32 high)
+    fn_ty = ir.FunctionType(ir.VoidType(), [T.as_pointer(), i32, i32])
+    fn = ir.Function(mod, fn_ty, name=fn_name)
+    arr, low, high = fn.args
+    arr.name, low.name, high.name = "arr", "low", "high"
+
+    entry = fn.append_basic_block("entry")
+    part = fn.append_basic_block("partition")
+    exit = fn.append_basic_block("exit")
+
+    b = ir.IRBuilder(entry)
+
+    # if (low < high)
+    cond = b.icmp_signed("<", low, high)
+    b.cbranch(cond, part, exit)
+
+    # --- Partition block
+    b.position_at_end(part)
+
+    # pivot = arr[high]
+    high_64 = b.sext(high, i64)
+    pivot_ptr = b.gep(arr, [high_64])
+    pivot = b.load(pivot_ptr, name="pivot")
+
+    # i = low - 1
+    i = b.alloca(i32, name="i")
+    i_init = b.sub(low, ir.Constant(i32, 1))
+    b.store(i_init, i)
+
+    # j = low
+    j = b.alloca(i32, name="j")
+    b.store(low, j)
+
+    loop = fn.append_basic_block("loop")
+    after_loop = fn.append_basic_block("after_loop")
+    body = fn.append_basic_block("body")
+    swap = fn.append_basic_block("swap")
+    skip_swap = fn.append_basic_block("skip_swap")
+
+    b.branch(loop)
+
+    # --- Loop: while (j < high)
+    b.position_at_end(loop)
+    j_val = b.load(j)
+    cond = b.icmp_signed("<", j_val, high)
+    b.cbranch(cond, body, after_loop)
+
+    # --- Body
+    b.position_at_end(body)
+    j64 = b.sext(j_val, i64)
+    elem_ptr = b.gep(arr, [j64])
+    elem = b.load(elem_ptr, name="elem")
+
+    if isinstance(T, ir.IntType):
+        cmp = b.icmp_signed("<=", elem, pivot)
+    else:
+        cmp = b.fcmp_ordered("<=", elem, pivot, fastmath=True)
+
+    b.cbranch(cmp, swap, skip_swap)
+
+    # --- Swap block
+    b.position_at_end(swap)
+    i_val = b.load(i)
+    i_next = b.add(i_val, ir.Constant(i32, 1))
+    b.store(i_next, i)
+
+    i64v = b.sext(i_next, i64)
+    iptr = b.gep(arr, [i64v])
+    ival = b.load(iptr)
+    # swap arr[i] and arr[j]
+    b.store(elem, iptr)
+    b.store(ival, elem_ptr)
+
+    b.branch(skip_swap)
+
+    # --- Skip swap
+    b.position_at_end(skip_swap)
+    j_next = b.add(j_val, ir.Constant(i32, 1))
+    b.store(j_next, j)
+    b.branch(loop)
+
+    # --- After loop
+    b.position_at_end(after_loop)
+    i_val = b.load(i)
+    i_plus1 = b.add(i_val, ir.Constant(i32, 1))
+
+    i64v = b.sext(i_plus1, i64)
+    iptr = b.gep(arr, [i64v])
+    ival = b.load(iptr)
+
+    # swap arr[i+1] and arr[high]
+    b.store(pivot, iptr)
+    b.store(ival, pivot_ptr)
+
+    # Now i+1 is the partition index
+    pi = i_plus1
+
+    # Recursive calls:
+    # quick_sort(arr, low, pi - 1)
+    low_call = low
+    high_call1 = b.sub(pi, ir.Constant(i32, 1))
+    b.call(fn, [arr, low_call, high_call1])
+
+    # quick_sort(arr, pi + 1, high)
+    low_call2 = b.add(pi, ir.Constant(i32, 1))
+    high_call2 = high
+    b.call(fn, [arr, low_call2, high_call2])
+
+    b.branch(exit)
+
+    # --- Exit
+    b.position_at_end(exit)
+    b.ret_void()
+
+    return str(mod)
+
 def _materialize(dtype: str) -> int:
     _ensure_target_machine()
 
@@ -167,3 +303,42 @@ def _materialize(dtype: str) -> int:
 
     except Exception as e:
         raise RuntimeError(f"Failed to materialize function for dtype {dtype}: {e}")
+
+
+def _materialize_quick(dtype: str) -> int:
+    _ensure_target_machine()
+
+    key = f"quick_{dtype}"
+    if key in _fn_ptr_cache:
+        return _fn_ptr_cache[key]
+
+    try:
+        llvm_ir = _build_quick_sort_ir(dtype)
+        mod = binding.parse_assembly(llvm_ir)
+        mod.verify()
+
+        try:
+            pm = binding.ModulePassManager()
+            pm.add_instruction_combining_pass()
+            pm.add_reassociate_pass()
+            pm.add_gvn_pass()
+            pm.add_cfg_simplification_pass()
+            pm.run(mod)
+        except AttributeError:
+            pass
+
+        engine = binding.create_mcjit_compiler(mod, _target_machine)
+        engine.finalize_object()
+        engine.run_static_constructors()
+
+        addr = engine.get_function_address(f"quick_sort_{dtype}")
+        if not addr:
+            raise RuntimeError(f"Failed to get address for quick_sort_{dtype}")
+
+        _fn_ptr_cache[key] = addr
+        _engines[key] = engine
+
+        return addr
+
+    except Exception as e:
+        raise RuntimeError(f"Failed to materialize quick sort function for dtype {dtype}: {e}")

pydatastructs/linear_data_structures/_backend/cpp/algorithms/quadratic_time_sort.hpp

@@ -612,6 +612,7 @@ static PyObject* bubble_sort_llvm(PyObject* self, PyObject* args, PyObject* kwds
     Py_INCREF(arr_obj);
     return arr_obj;
 }
+
 // Selection Sort
 static PyObject* selection_sort_impl(PyObject* array, size_t lower, size_t upper,
     PyObject* comp) {