What syntax does a disassembled .s file is not acceptable in nasm? - gcc

Question

This code is a C program (bubble sort) disassembled into assembly. How can I make the following code run if I put it in a .asm file and use nasm to assemble? If you know what needs changing, please say what to change it to. For instance I understand that nasm won't accept DWORD PTR, but I haven't found out what to do instead. Thanks
.file "sort.c" .intel_syntax noprefix .text .globl
sort .type sort, #function
sort: .LFB0:
.cfi_startproc
push rbp
.cfi_def_cfa_offset 16
.cfi_offset 6, -16
mov rbp, rsp
.cfi_def_cfa_register 6
mov QWORD PTR [rbp-24], rdi
mov DWORD PTR [rbp-28], esi
mov DWORD PTR [rbp-12], 0
jmp .L2
.L6:
mov DWORD PTR [rbp-8], 0
jmp .L3
.L5:
mov eax, DWORD PTR [rbp-8]
cdqe
sal rax, 2
add rax, QWORD PTR [rbp-24]
mov edx, DWORD PTR [rax]
mov eax, DWORD PTR [rbp-8]
cdqe
add rax, 1
sal rax, 2
add rax, QWORD PTR [rbp-24]
mov eax, DWORD PTR [rax]
cmp edx, eax
jle .L4
mov eax, DWORD PTR [rbp-8]
cdqe
sal rax, 2
add rax, QWORD PTR [rbp-24]
mov eax, DWORD PTR [rax]
mov DWORD PTR [rbp-4], eax
mov eax, DWORD PTR [rbp-8]
cdqe
sal rax, 2
add rax, QWORD PTR [rbp-24]
mov edx, DWORD PTR [rbp-8]
movsx rdx, edx
add rdx, 1
sal rdx, 2
add rdx, QWORD PTR [rbp-24]
mov edx, DWORD PTR [rdx]
mov DWORD PTR [rax], edx
mov eax, DWORD PTR [rbp-8]
cdqe
add rax, 1
sal rax, 2
add rax, QWORD PTR [rbp-24]
mov edx, DWORD PTR [rbp-4]
mov DWORD PTR [rax], edx
.L4:
add DWORD PTR [rbp-8], 1
.L3:
mov eax, DWORD PTR [rbp-28]
sub eax, 1
sub eax, DWORD PTR [rbp-12]
cmp eax, DWORD PTR [rbp-8]
jg .L5
add DWORD PTR [rbp-12], 1
.L2:
mov eax, DWORD PTR [rbp-28]
sub eax, 1
cmp eax, DWORD PTR [rbp-12]
jg .L6
pop rbp
.cfi_def_cfa 7, 8
ret
.cfi_endproc
.LFE0:
.size sort, .-sort
.ident "GCC: (Ubuntu/Linaro 4.6.3-1ubuntu5) 4.6.3"
.section .note.GNU-stack,"",#progbits

Answer 1

Just remove PTR and all nonsensical .somethings.
This assembles just fine:
; file: gas-nasm-sort.asm
bits 64
sort:
push rbp
mov rbp, rsp
mov QWORD [rbp-24], rdi
mov DWORD [rbp-28], esi
mov DWORD [rbp-12], 0
jmp .L2
.L6:
mov DWORD [rbp-8], 0
jmp .L3
.L5:
mov eax, DWORD [rbp-8]
cdqe
sal rax, 2
add rax, QWORD [rbp-24]
mov edx, DWORD [rax]
mov eax, DWORD [rbp-8]
cdqe
add rax, 1
sal rax, 2
add rax, QWORD [rbp-24]
mov eax, DWORD [rax]
cmp edx, eax
jle .L4
mov eax, DWORD [rbp-8]
cdqe
sal rax, 2
add rax, QWORD [rbp-24]
mov eax, DWORD [rax]
mov DWORD [rbp-4], eax
mov eax, DWORD [rbp-8]
cdqe
sal rax, 2
add rax, QWORD [rbp-24]
mov edx, DWORD [rbp-8]
movsx rdx, edx
add rdx, 1
sal rdx, 2
add rdx, QWORD [rbp-24]
mov edx, DWORD [rdx]
mov DWORD [rax], edx
mov eax, DWORD [rbp-8]
cdqe
add rax, 1
sal rax, 2
add rax, QWORD [rbp-24]
mov edx, DWORD [rbp-4]
mov DWORD [rax], edx
.L4:
add DWORD [rbp-8], 1
.L3:
mov eax, DWORD [rbp-28]
sub eax, 1
sub eax, DWORD [rbp-12]
cmp eax, DWORD [rbp-8]
jg .L5
add DWORD [rbp-12], 1
.L2:
mov eax, DWORD [rbp-28]
sub eax, 1
cmp eax, DWORD [rbp-12]
jg .L6
pop rbp
ret
Command:
nasm gas-nasm-sort.asm -f bin -o gas-nasm-sort.bin
But again, there's NASM documentation. Read it. In particular these sections:
2.2.2 NASM Requires Square Brackets For Memory References
2.2.3 NASM Doesn't Store Variable Types