Thank you very much Richard, Very good starter for me but I am actually having the hardest time with variables, pointers etc...
I know this may be a lot to ask but, If you could help me with this I will very much appreciate it. Thanks again very much! I will be sure to include your name in my paper :) > On Tue, Sep 3, 2013 at 7:59 PM, <ttur...@cs.bilkent.edu.tr> wrote: >> Sorry forgot to mention, my name is Tuncer. >> Again any help would be much appreciated. >> I know these maybe simple for some of you if you could lend me a hand, you >> will be doing a great deal of help. >> Changed the subject for better understanding, >> Thanks again guys :) > Something like > oldop = gimple_assign_rhs1 (stmt); > gsi = gsi_for_stmt (stmt); > newop = force_gimple_operand_gsi (&gsi, fold_build2 (BIT_IOR_EXPR, > TREE_TYPE (oldop), oldop, build_int_cst (TREE_TYPE (oldop), 1<<3)), true, NULL_TREE, true, GSI_CONTINUE_LINKING); > gimple_assign_set_rhs1 (stmt, newop); > update_stmt (stmt); >>> Hi, >>> I am a student at Bilkent Uni. in Turkey and using GCC as a tool for my >>> M.S. Thesis which is about Software Fault Tolerance. >>> I am stuck, in terms of implementing bit flips in the operands of a gimple >>> statement. >>> I need to inject bit flips to all kinds of operands, constant integers, >>> floats, variables, pointers etc... >>> It is simpler for constants, but I am having a hard time to get the value >>> of pointers and other variables. >>> My objective is to simply change the value of a tree operand, by injecting >>> a new instruction that changes the value or directly change the operand >>> to >>> a bit flipped value. >>> For constant integers I did something like this: >>> int valueBefore = TREE_INT_CST_LOW(operands[i]); >>> int valueAfter = (valueBefore ^ (1u << 2)); >>> tree number = >>> build_int_cst (integer_type_node, valueAfter); >>> I would love it if you can help me and >>> may even implement a tool for GCC for error injection purposes. Any help would be much appreciated! >>> Thank you very much!
