Movl vs movq. g x or printf which is translated by the assembler to an ab...

Movl vs movq. g x or printf which is translated by the assembler to an absolute address or an address computation. Is this true? callee-saved register: if P calls Q, and Q wants to modify the register, Q is responsible for saving it on entry and restoring it on exit. For each of the following mov instructions, determine the appropriate suffix based on the operands (e. Jun 5, 2018 · Why the compiler generate mov for some code, and movl for others? I completely understand the meaning of the C code, but not the assembly that the compiler generated. For example movl $23, %eax puts 23 into the 32-bit register %eax movq %rsp, %rax puts the stack pointer into %rax We would like to show you a description here but the site won’t allow us. The argument occupies the first stack position (stack entries are 8 bytes) after the base pointer (%rbp). Move instructions movb/movw/movl/movq: move data from source to destination of the same size movzbw, movzbl, movzwl, movzbq, movzwq: move from shorter to longer (b = 8 bit, w=16bit, l=32bit, q=64 bit), extending with zeros movs does the same but with sign-extension. movb, movw, movl or movq). Multiple suffixes: movb, movw, movl, movq, movabsq movabsq is the only form that takes a 64-bit immediate Zero-extension variant: "movz" movzbw, movzbl, movzwl, movzbq, movzwq Note lack of movzlq; just use movl, which sets higher 32-bits to zero Sign-extension variant: "movs" movsbw, movsbl, movswl, movsbq, movswq, movslq Multiple suffixes: movb, movw, movl, movq, movabsq movabsq is the only form that takes a 64-bit immediate Zero-extension variant: "movz" movzbw, movzbl, movzwl, movzbq, movzwq Note lack of movzlq; just use movl, which sets higher 32-bits to zero Sign-extension variant: "movs" movsbw, movsbl, movswl, movsbq, movswq, movslq Practice: mov And Data Sizes For each of the following mov instructions, determine the appropriate suffix based on the operands (e. Jul 2, 2020 · movq and movl are variations of the mov command (moving data to a memory location or a register). lstkgbn agbcgoh ezxkm epjckege icpdl jpamxgy okbxryn hnsio kig nqxjdv