(original) (raw)

Hi there,

I'm working on an MIR transformation for X86, and I need to get all memory addresses accessed by any X86 instruction. I've been using MachineInstr::memoperands() to iterate over all MachineMemOperands and using X86II::getMemoryOperandNo() and X86II::getOperandBias() to get the index of the base\_reg MachineOperand. This seems to work fine for most instructions, until I saw the following instruction:

X86: pushq 0x20(%rbx)

MIR: PUSH64rmm renamable rbx<spanstyle="background−color:transparent;font−variant−numeric:normal;font−variant−east−asian:normal;font−size:9pt;font−family:Consolas;color:rgb(102,102,0);vertical−align:baseline;white−space:pre−wrap">,<spanstyle="background−color:transparent;font−variant−numeric:normal;font−variant−east−asian:normal;font−size:9pt;font−family:Consolas;color:rgb(0,0,0);vertical−align:baseline;white−space:pre−wrap"><spanstyle="background−color:transparent;font−variant−numeric:normal;font−variant−east−asian:normal;font−size:9pt;font−family:Consolas;color:rgb(0,102,102);vertical−align:baseline;white−space:pre−wrap">1<spanstyle="background−color:transparent;font−variant−numeric:normal;font−variant−east−asian:normal;font−size:9pt;font−family:Consolas;color:rgb(102,102,0);vertical−align:baseline;white−space:pre−wrap">,<spanstyle="background−color:transparent;font−variant−numeric:normal;font−variant−east−asian:normal;font−size:9pt;font−family:Consolas;color:rgb(0,0,0);vertical−align:baseline;white−space:pre−wrap">rbx, 1, rbx<spanstyle="background−color:transparent;font−variant−numeric:normal;font−variant−east−asian:normal;font−size:9pt;font−family:Consolas;color:rgb(102,102,0);vertical−align:baseline;white−space:pre−wrap">,<spanstyle="background−color:transparent;font−variant−numeric:normal;font−variant−east−asian:normal;font−size:9pt;font−family:Consolas;color:rgb(0,0,0);vertical−align:baseline;white−space:pre−wrap"><spanstyle="background−color:transparent;font−variant−numeric:normal;font−variant−east−asian:normal;font−size:9pt;font−family:Consolas;color:rgb(0,102,102);vertical−align:baseline;white−space:pre−wrap">1<spanstyle="background−color:transparent;font−variant−numeric:normal;font−variant−east−asian:normal;font−size:9pt;font−family:Consolas;color:rgb(102,102,0);vertical−align:baseline;white−space:pre−wrap">,<spanstyle="background−color:transparent;font−variant−numeric:normal;font−variant−east−asian:normal;font−size:9pt;font−family:Consolas;color:rgb(0,0,0);vertical−align:baseline;white−space:pre−wrap">noreg, 32, noreg<spanstyle="background−color:transparent;font−variant−numeric:normal;font−variant−east−asian:normal;font−size:9pt;font−family:Consolas;color:rgb(102,102,0);vertical−align:baseline;white−space:pre−wrap">,<spanstyle="background−color:transparent;font−variant−numeric:normal;font−variant−east−asian:normal;font−size:9pt;font−family:Consolas;color:rgb(0,0,0);vertical−align:baseline;white−space:pre−wrap"><spanstyle="background−color:transparent;font−variant−numeric:normal;font−variant−east−asian:normal;font−size:9pt;font−family:Consolas;color:rgb(0,0,136);vertical−align:baseline;white−space:pre−wrap">implicit<spanstyle="background−color:transparent;font−variant−numeric:normal;font−variant−east−asian:normal;font−size:9pt;font−family:Consolas;color:rgb(102,102,0);vertical−align:baseline;white−space:pre−wrap">−<spanstyle="background−color:transparent;font−variant−numeric:normal;font−variant−east−asian:normal;font−size:9pt;font−family:Consolas;color:rgb(0,0,136);vertical−align:baseline;white−space:pre−wrap">def<spanstyle="background−color:transparent;font−variant−numeric:normal;font−variant−east−asian:normal;font−size:9pt;font−family:Consolas;color:rgb(0,0,0);vertical−align:baseline;white−space:pre−wrap">noreg, implicit-def noreg<spanstyle="background−color:transparent;font−variant−numeric:normal;font−variant−east−asian:normal;font−size:9pt;font−family:Consolas;color:rgb(102,102,0);vertical−align:baseline;white−space:pre−wrap">,<spanstyle="background−color:transparent;font−variant−numeric:normal;font−variant−east−asian:normal;font−size:9pt;font−family:Consolas;color:rgb(0,0,0);vertical−align:baseline;white−space:pre−wrap"><spanstyle="background−color:transparent;font−variant−numeric:normal;font−variant−east−asian:normal;font−size:9pt;font−family:Consolas;color:rgb(0,0,136);vertical−align:baseline;white−space:pre−wrap">implicit<spanstyle="background−color:transparent;font−variant−numeric:normal;font−variant−east−asian:normal;font−size:9pt;font−family:Consolas;color:rgb(102,102,0);vertical−align:baseline;white−space:pre−wrap">−<spanstyle="background−color:transparent;font−variant−numeric:normal;font−variant−east−asian:normal;font−size:9pt;font−family:Consolas;color:rgb(0,0,136);vertical−align:baseline;white−space:pre−wrap">def<spanstyle="background−color:transparent;font−variant−numeric:normal;font−variant−east−asian:normal;font−size:9pt;font−family:Consolas;color:rgb(0,0,0);vertical−align:baseline;white−space:pre−wrap">rsp, implicit $rsp

For the above MachineInstr, MachineInstr::getNumMemOperands() returns 0: there's no MachineMemOperands. However, this instruction clearly accesses the memory address specified by \[%rbx + 0x20\]. I wonder how I can get the memory addresses for instructions like this?

Thanks!

Yuanfeng Peng