GH-115685: Optimize `TO_BOOL` and variants based on truthiness of input. (GH-116311)

1 files changed, 22 insertions, 0 deletions

diff --git a/Python/optimizer_analysis.c b/Python/optimizer_analysis.c
index a326e22..1e1d552 100644
--- a/Python/optimizer_analysis.c
+++ b/Python/optimizer_analysis.c
@@ -298,9 +298,31 @@ remove_globals(_PyInterpreterFrame *frame, _PyUOpInstruction *buffer,
 #define sym_set_type _Py_uop_sym_set_type
 #define sym_set_const _Py_uop_sym_set_const
 #define sym_is_bottom _Py_uop_sym_is_bottom
+#define sym_truthiness _Py_uop_sym_truthiness
 #define frame_new _Py_uop_frame_new
 #define frame_pop _Py_uop_frame_pop
 
+static int
+optimize_to_bool(
+    _PyUOpInstruction *this_instr,
+    _Py_UOpsContext *ctx,
+    _Py_UopsSymbol *value,
+    _Py_UopsSymbol **result_ptr)
+{
+    if (sym_matches_type(value, &PyBool_Type)) {
+        REPLACE_OP(this_instr, _NOP, 0, 0);
+        *result_ptr = value;
+        return 1;
+    }
+    int truthiness = sym_truthiness(value);
+    if (truthiness >= 0) {
+        PyObject *load = truthiness ? Py_True : Py_False;
+        REPLACE_OP(this_instr, _POP_TOP_LOAD_CONST_INLINE_BORROW, 0, (uintptr_t)load);
+        *result_ptr = sym_new_const(ctx, load);
+        return 1;
+    }
+    return 0;
+}
 
 /* 1 for success, 0 for not ready, cannot error at the moment. */
 static int