What is the c code of the following MIPS function?

0000000000400e70 :

400e70: 48 89 5c 24 e8 mov %rbx,-0x18(%rsp)

400e75: 48 89 6c 24 f0 mov %rbp,-0x10(%rsp)

400e7a: 4c 89 64 24 f8 mov %r12,-0x8(%rsp)

400e7f: 48 83 ec 18 sub $0x18,%rsp

400e83: 89 fb mov %edi,%ebx

400e85: 89 f5 mov %esi,%ebp

400e87: 85 ff test %edi,%edi

400e89: 7f 07 jg 400e92

400e8b: bd 00 00 00 00 mov $0x0,%ebp

400e90: eb 20 jmp 400eb2

400e92: 83 ff 01 cmp $0x1,%edi

400e95: 74 1b je 400eb2

400e97: 8d 7b ff lea -0x1(%rbx),%edi

400e9a: e8 d1 ff ff ff callq 400e70

400e9f: 41 89 c4 mov %eax,%r12d

400ea2: 8d 7b fe lea -0x2(%rbx),%edi

400ea5: 89 ee mov %ebp,%esi

400ea7: e8 c4 ff ff ff callq 400e70

400eac: 41 01 c4 add %eax,%r12d

400eaf: 44 01 e5 add %r12d,%ebp

400eb2: 89 e8 mov %ebp,%eax

400eb4: 48 8b 1c 24 mov (%rsp),%rbx

400eb8: 48 8b 6c 24 08 mov 0x8(%rsp),%rbp

400ebd: 4c 8b 64 24 10 mov 0x10(%rsp),%r12

400ec2: 48 83 c4 18 add $0x18,%rsp

400ec6: c3 retq