问题
i understand what the other calls are doing but when i get line 36, i don't get what's happening?
my 3 parameters are rsi = 5, rdx = 6, rcx = 7
On line 26 my %rax = 25 then on line 30 my rsi changes from 5 to 37
can you explain why this happens? and what is 0x40272e
0x0000000000401212 <+0>: sub $0x8,%rsp # subtract 8 from rsp
0x0000000000401216 <+4>: lea -0x1(%rdx),%rax # rax = -1 + rdx
0x000000000040121a <+8>: cmp $0xf,%rax # rax ?? 0xf '-1' 'SI'
0x000000000040121e <+12>: ja 0x40124f <phase_3+61> # if(rax > 0xf) goto L1
0x0000000000401220 <+14>: cmp $0x2,%rdi # rdi ?? 0x2
0x0000000000401224 <+18>: jle 0x40124f <phase_3+61> # if(rdi <= 0x2) goto L1
0x0000000000401226 <+20>: cmp $0xa,%rsi # rsi ?? 0xa '10' 'LF'
0x000000000040122a <+24>: ja 0x40124f <phase_3+61> # if(rsi > 0xa) goto L1
0x000000000040122c <+26>: lea (%rsi,%rsi,4),%rax # rax = 5 * rsi
0x0000000000401230 <+30>: movzwl 0x40272e(,%rax,4),%esi # esi = 0 + rax * 4
0x0000000000401238 <+38>: movsbq 0x402801(,%rdx,4),%rax # rax = 0 + rdx * 4
0x0000000000401241 <+47>: xor %rax,%rsi # rsi ^ rax
0x0000000000401244 <+50>: sete %al # if (rsi == rax) al = 1
0x0000000000401247 <+53>: movzbl %al,%eax # rax = al
0x000000000040124a <+56>: cmp %rcx,%rsi # rsi ?? rcx
0x000000000040124d <+59>: je 0x40125b <phase_3+73> # if (rsi == rcx) goto L2
0x000000000040124f <+61>: callq 0x401b17 <bomb_explodes> # boom boom
0x0000000000401254 <+66>: mov $0xffffffffffffffff,%rax # rax = -1
0x000000000040125b <+73>: add $0x8,%rsp # add 8 to rsp
0x000000000040125f <+77>: retq # return rax
来源：https://stackoverflow.com/questions/53146459/assembler-code-need-help-understand-what-movzwl-0x40272e-rax-4-esi-is-doi