I have been reviewing the compile.c module with respect to the use of JUMP_IF_XXX opcodes, and the frequency with which these opcodes are followed by a POP_TOP instruction. It seems to me that there are two kinds of uses cases for these opcodes, The first use case could be expressed as POP_THEN_JUMP_IF_XXXX The second use case could be expressed as JUMP_IF_XXX_ELSE_POP Listed below are the use cases for these instructions, and the functions in compile.c that they apear in. The form is JUMP_IF_XXX(top-of-stack-if-no-jump, top-of-stack-if-jump) com_assert_stmt - JUMP_IF_TRUE(-,-) com_if_stmt - JUMP_IF_FALSE(-,-) com_while_stmt - JUMP_IF_FALSE(-,-) com_try_except - JUMP_IF_FALSE(-,-) com_list_if - JUMP_IF_FALSE(-, -) com_comparison - JUMP_IF_FALSE(-, 0) com_and_test - JUMP_IF_FALSE(-, 0) com_test - JUMP_IF_TRUE(-, 1) Below is a minimally intrusive implementation of the expansion of JUMP_IF_FALSE into two opcodes for handling the two use cases. case JUMP_IF_FALSE_ELSE_POP: case POP_THEN_JUMP_IF_FALSE: NEXTARG(oparg); err = PyObject_IsTrue(TOP()); if (err > 0) { err = 0; POP(); } else if (err == 0) { if (opcode == POP_THEN_JUMP_IF_FALSE) POP(); JUMPBY(oparg); } else break; continue; Comments, suggestions, etc, appreciated.