Edinburgh IMP77 Compiler - Version 8.4 1 ! i77 collatz.imp .Ltext0: _imp_PROMPT: .LFB69: pushl %ebp movl %esp, %ebp pushl %edi pushl %esi pushl %ebx subl $12, %esp call __x86.get_pc_thunk.bx addl $_GLOBAL_OFFSET_TABLE_, %ebx subl $12, %esp leal __PRETTY_FUNCTION__.5536@GOTOFF(%ebx), %eax pushl %eax call check_instream@PLT addl $16, %esp leal 8(%ebp), %edx movl _imp_promptstr@GOT(%ebx), %eax movl %edx, %ebx movl $256, %edx movl (%ebx), %ecx movl %ecx, (%eax) movl -4(%ebx,%edx), %ecx movl %ecx, -4(%eax,%edx) leal 4(%eax), %edi andl $-4, %edi subl %edi, %eax subl %eax, %ebx addl %eax, %edx andl $-4, %edx movl %edx, %eax shrl $2, %eax movl %ebx, %esi movl %eax, %ecx rep movsl nop leal -12(%ebp), %esp popl %ebx popl %esi popl %edi popl %ebp ret .LFE69: EVENCOLLATZ.6031: .LFB191: 2 ! ./collatz 3 ! 837799 4 ! ./collatz 5 ! 8400511 6 7 ! https://www.reddit.com/r/C_Programming/comments/1eoc0v3/does_any_c_compiler_other_than_gcc_support_nested/ 8 9 ! This is an imp77 source that corresponds more or less to 10 ! the example C source in the accompanying ccollatz.c file. 11 12 %begin leal 4(%esp), %ecx andl $-16, %esp pushl -4(%ecx) pushl %ebp movl %esp, %ebp pushl %edi pushl %esi pushl %ebx pushl %ecx subl $824, %esp call __x86.get_pc_thunk.bx addl $_GLOBAL_OFFSET_TABLE_, %ebx movl %ecx, %eax movl 4(%eax), %edx movl %edx, -828(%ebp) movl %gs:20, %esi movl %esi, -28(%ebp) xorl %esi, %esi leal 8(%ebp), %edx movl %edx, -800(%ebp) subl $8, %esp pushl -828(%ebp) pushl (%eax) call _imp_initialise@PLT addl $16, %esp 13 %integer odd1 = 1, odd2 = 2 movl $1, %eax movl %eax, -808(%ebp) movl $2, %eax movl %eax, -804(%ebp) .LBB49: 14 %const %integer final value = 0, MAX FACTOR = (((~0)>>1)-1)//3 15 ! The integer overflow test here will trigger 16 ! at 0x7FFFFFFF rather than 0xFFFFFFFF because 17 ! this imp77 does not support unsigned 32-bit 18 ! integers. Other than that case, this code 19 ! should give the same results as the C version. 20 21 %const %integer terminating value = 1 22 23 %routine show collatz length(%integer i, %integername max) pushl %ebp movl %esp, %ebp pushl %edi pushl %esi pushl %ebx subl $2364, %esp call __x86.get_pc_thunk.bx addl $_GLOBAL_OFFSET_TABLE_, %ebx movl %ebx, %edi movl %edi, -2368(%ebp) movl 12(%ebp), %eax movl %ecx, %ebx movl %ebx, -2372(%ebp) movl %ecx, -2364(%ebp) movl %gs:20, %esi movl %esi, -28(%ebp) xorl %esi, %esi leal 8(%ebp), %edx movl %edx, -2336(%ebp) movl %eax, -2340(%ebp) movl %ebx, -2344(%ebp) 24 ! Returns 0 for the length if there was an integer overflow. 25 26 %integer base value = final value + 1 movl $1, %eax movl %eax, -2348(%ebp) .LBB31: 27 28 %integerfnspec odd collatz(%integer i); ! mutual recursion requires a forward declaration! 29 30 %integerfn even collatz(%integer i) pushl %ebp movl %esp, %ebp pushl %ebx subl $20, %esp call __x86.get_pc_thunk.ax addl $_GLOBAL_OFFSET_TABLE_, %eax movl %ecx, %ebx movl %ecx, -12(%ebp) 31 %if i < terminating value %then %result = final value cmpl $0, 8(%ebp) jg .L12 movl $0, %eax jmp .L5 .L12: nop .L4: 32 %if i > max %then max = i movl 8(%ebx), %eax movl (%eax), %eax cmpl %eax, 8(%ebp) jle .L13 movl 8(%ebx), %eax movl 8(%ebp), %edx movl %edx, (%eax) jmp .L7 .L13: nop .L7: 33 %if i&odd2 # 0 %start ;! 'optimization' :-) movl 4(%ebx), %eax movl 4(%eax), %eax testl %eax, %eax sete %al movzbl %al, %eax andl 8(%ebp), %eax testl %eax, %eax jne .L14 nop .L9: 34 %result = base value+odd collatz(i>>1); ! (really just an excuse to justify this use of mutual recursion) movl 8(%ebp), %eax shrl %eax subl $12, %esp pushl %eax movl %ebx, %ecx call ODDCOLLATZ.6029 addl $16, %esp movl %eax, %edx movl (%ebx), %eax addl %edx, %eax jmp .L5 .L14: 35 %finish %else %start 36 %result = base value+even collatz(i>>1) movl 8(%ebp), %eax shrl %eax subl $12, %esp pushl %eax movl %ebx, %ecx call EVENCOLLATZ.6031 addl $16, %esp movl %eax, %edx movl (%ebx), %eax addl %edx, %eax .L5: 37 %finish 38 %end movl -4(%ebp), %ebx leave ret .LFE191: .section .rodata .align 32 .LC2: .byte 24 .string "The Collatz sequence for" .zero 230 .align 32 .LC3: .byte 6 .string " takes" .zero 248 .align 32 .LC4: .byte 56 .string " an unknown number of steps (we hit an integer overflow)" .zero 198 .align 32 .LC5: .byte 40 .string " steps and the largest value reached was" .zero 214 SHOWCOLLATZLENGTH.6025: .LFB190: 39 40 %integerfn odd collatz(%integer i) pushl %ebp movl %esp, %ebp pushl %edi pushl %esi pushl %ebx subl $812, %esp call __x86.get_pc_thunk.bx addl $_GLOBAL_OFFSET_TABLE_, %ebx movl %ecx, -816(%ebp) movl %ecx, -812(%ebp) movl %gs:20, %eax movl %eax, -28(%ebp) xorl %eax, %eax 41 %if i <= terminating value %then %result = final value cmpl $1, 8(%ebp) jg .L51 movl $0, %eax jmp .L40 .L51: nop .L39: 42 %if i > max %then max = i movl -816(%ebp), %eax movl 8(%eax), %eax movl (%eax), %eax cmpl %eax, 8(%ebp) jle .L52 movl -816(%ebp), %eax movl 8(%eax), %eax movl 8(%ebp), %edx movl %edx, (%eax) jmp .L42 .L52: nop .L42: 43 %if i > MAX FACTOR %then %signal 15,1,1; ! next call would cause integer overflow... cmpl $715827882, 8(%ebp) jle .L53 leal -540(%ebp), %eax subl $8, %esp leal .LC6@GOTOFF(%ebx), %edx pushl %edx pushl %eax call _imp_c2istr@PLT addl $12, %esp movl _imp_current_line@GOT(%ebx), %eax movl (%eax), %eax testl %eax, %eax je .L45 movl _imp_current_line@GOT(%ebx), %eax movl (%eax), %eax movl %eax, -820(%ebp) jmp .L46 .L45: movl $43, -820(%ebp) .L46: movl _imp_current_file@GOT(%ebx), %eax movl (%eax), %eax testl %eax, %eax je .L47 movl _imp_current_file@GOT(%ebx), %eax movl (%eax), %edx leal -284(%ebp), %eax subl $8, %esp pushl %edx pushl %eax call _imp_c2istr@PLT addl $12, %esp jmp .L48 .L47: .LBB59: leal -284(%ebp), %eax leal .LC0@GOTOFF(%ebx), %edx movl $64, %ecx movl %eax, %edi movl %edx, %esi rep movsl leal -796(%ebp), %eax leal -284(%ebp), %edx movl $64, %ecx movl %eax, %edi movl %edx, %esi rep movsl .LBE59: leal -284(%ebp), %eax leal -796(%ebp), %edx movl $64, %ecx movl %eax, %edi movl %edx, %esi rep movsl .L48: pushl $1 pushl $1 pushl $15 subl $256, %esp movl %esp, %eax movl %eax, %edi leal -540(%ebp), %eax movl $64, %edx movl %eax, %esi movl %edx, %ecx rep movsl pushl -820(%ebp) subl $256, %esp movl %esp, %eax movl %eax, %edi leal -284(%ebp), %eax movl $64, %edx movl %eax, %esi movl %edx, %ecx rep movsl call _signal_event@PLT addl $528, %esp jmp .L44 .L53: nop .L44: 44 %result = base value+even collatz((i<<1)+i+1) movl 8(%ebp), %eax leal (%eax,%eax), %edx movl 8(%ebp), %eax addl %edx, %eax addl $1, %eax subl $12, %esp pushl %eax movl -816(%ebp), %esi movl %esi, %ecx call EVENCOLLATZ.6031 addl $16, %esp movl %eax, %edx movl %esi, %eax movl (%eax), %eax addl %edx, %eax .L40: 45 %end movl -28(%ebp), %edi xorl %gs:20, %edi je .L49 call __stack_chk_fail_local .L49: leal -12(%ebp), %esp popl %ebx popl %esi popl %edi popl %ebp ret .LFE192: .section .rodata .align 4 __PRETTY_FUNCTION__.5536: .string "_imp_PROMPT" .section .text.__x86.get_pc_thunk.ax,"axG",@progbits,__x86.get_pc_thunk.ax,comdat .globl __x86.get_pc_thunk.ax .hidden __x86.get_pc_thunk.ax __x86.get_pc_thunk.ax: .LFB193: movl (%esp), %eax ret .LFE193: .section .text.__x86.get_pc_thunk.bx,"axG",@progbits,__x86.get_pc_thunk.bx,comdat .globl __x86.get_pc_thunk.bx .hidden __x86.get_pc_thunk.bx __x86.get_pc_thunk.bx: .LFB194: movl (%esp), %ebx ret .LFE194: .Letext0: 46 47 print string("The Collatz sequence for") leal -284(%ebp), %eax movl %edi, %ebx leal .LC2@GOTOFF(%ebx), %edx movl $64, %ecx movl %eax, %edi movl %edx, %esi rep movsl leal -2332(%ebp), %eax leal -284(%ebp), %edx movl $64, %ecx movl %eax, %edi movl %edx, %esi rep movsl leal -1052(%ebp), %eax leal -2332(%ebp), %edx movl $64, %ecx movl %eax, %edi movl %edx, %esi rep movsl .LBE31: .LBB32: .LBB33: subl $256, %esp movl %esp, %eax movl %eax, %edi leal -1052(%ebp), %eax movl $64, %edx movl %eax, %esi movl %edx, %ecx rep movsl movl %ebx, %edi movl %edi, %ebx call _imp_printstring@PLT addl $256, %esp .LBE33: .LBE32: 48 write(i, 1) subl $8, %esp pushl $1 pushl 8(%ebp) movl %edi, %ebx call _imp_writeint@PLT addl $16, %esp .LBB34: 49 print string(" takes") leal -284(%ebp), %eax movl %edi, %ebx leal .LC3@GOTOFF(%ebx), %edx movl $64, %ecx movl %eax, %edi movl %edx, %esi rep movsl leal -2076(%ebp), %eax leal -284(%ebp), %edx movl $64, %ecx movl %eax, %edi movl %edx, %esi rep movsl leal -796(%ebp), %eax leal -2076(%ebp), %edx movl $64, %ecx movl %eax, %edi movl %edx, %esi rep movsl .LBE34: .LBB35: .LBB36: subl $256, %esp movl %esp, %eax movl %eax, %edi leal -796(%ebp), %eax movl $64, %edx movl %eax, %esi movl %edx, %ecx rep movsl movl %ebx, %esi movl %esi, %ebx call _imp_printstring@PLT addl $256, %esp .LBE36: .LBE35: 50 51 %onevent 15 %start subl $8, %esp pushl $1 movl %esi, %ebx movl _imp_event@GOT(%ebx), %eax leal 532(%eax), %eax pushl %eax movl %esi, %ebx call __sigsetjmp@PLT addl $16, %esp testl %eax, %eax jne .L17 .LBB37: movl $15, -1564(%ebp) movl $0, -2356(%ebp) .LBB38: movl $0, -2352(%ebp) jmp .L18 .L19: movl -2352(%ebp), %eax movl -1564(%ebp,%eax,4), %eax movl $1, %edx movl %eax, %ecx sall %cl, %edx movl %edx, %eax orl %eax, -2356(%ebp) addl $1, -2352(%ebp) .L18: cmpl $0, -2352(%ebp) je .L19 .LBE38: movl -2356(%ebp), %eax .LBE37: subl $8, %esp pushl %eax movl -2368(%ebp), %ebx movl _imp_event@GOT(%ebx), %eax pushl %eax call _imp_on_event_enter@PLT addl $16, %esp testl %eax, %eax jne .L29 .L17: .LBB39: nop .L20: 52 print string(" an unknown number of steps (we hit an integer overflow)") leal -1564(%ebp), %eax movl -2368(%ebp), %ebx leal .LC4@GOTOFF(%ebx), %edx movl $64, %ecx movl %eax, %edi movl %edx, %esi rep movsl leal -1820(%ebp), %eax leal -1564(%ebp), %edx movl $64, %ecx movl %eax, %edi movl %edx, %esi rep movsl leal -540(%ebp), %eax leal -1820(%ebp), %edx movl $64, %ecx movl %eax, %edi movl %edx, %esi rep movsl .LBE39: .LBB40: .LBB41: subl $256, %esp movl %esp, %eax movl %eax, %edi leal -540(%ebp), %eax movl $64, %edx movl %eax, %esi movl %edx, %ecx rep movsl movl %ebx, %edi movl %edi, %ebx call _imp_printstring@PLT addl $256, %esp .LBE41: .LBE40: .LBB42: .LBB43: movl %edi, %ebx call _imp_newline@PLT .LBE43: .LBE42: 53 newline 54 %return jmp .L15 .L29: 55 %finish 56 57 %if i&odd1 # 0 %then write(odd collatz(i), 1) %else write(even collatz(i), 1) movl -2372(%ebp), %eax movl (%eax), %eax testl %eax, %eax sete %al movzbl %al, %eax andl 8(%ebp), %eax testl %eax, %eax jne .L30 subl $12, %esp leal -2348(%ebp), %eax pushl 8(%ebp) movl %eax, %ecx call ODDCOLLATZ.6029 addl $16, %esp subl $8, %esp pushl $1 pushl %eax movl -2368(%ebp), %ebx call _imp_writeint@PLT addl $16, %esp jmp .L24 .L23: .L30: nop subl $12, %esp leal -2348(%ebp), %eax pushl 8(%ebp) movl %eax, %ecx call EVENCOLLATZ.6031 addl $16, %esp subl $8, %esp pushl $1 pushl %eax movl -2368(%ebp), %ebx call _imp_writeint@PLT addl $16, %esp .L24: .LBB44: 58 print string(" steps and the largest value reached was") leal -1564(%ebp), %eax movl -2368(%ebp), %ebx leal .LC5@GOTOFF(%ebx), %edx movl $64, %ecx movl %eax, %edi movl %edx, %esi rep movsl leal -1308(%ebp), %eax leal -1564(%ebp), %edx movl $64, %ecx movl %eax, %edi movl %edx, %esi rep movsl leal -284(%ebp), %eax leal -1308(%ebp), %edx movl $64, %ecx movl %eax, %edi movl %edx, %esi rep movsl .LBE44: .LBB45: .LBB46: subl $256, %esp movl %esp, %eax movl %eax, %edi leal -284(%ebp), %eax movl $64, %edx movl %eax, %esi movl %edx, %ecx rep movsl movl %ebx, %esi movl %esi, %ebx call _imp_printstring@PLT addl $256, %esp .LBE46: .LBE45: 59 write(max, 1) movl -2340(%ebp), %eax movl (%eax), %eax subl $8, %esp pushl $1 pushl %eax movl %esi, %ebx call _imp_writeint@PLT addl $16, %esp .LBB47: .LBB48: movl %esi, %ebx call _imp_newline@PLT .LBE48: .LBE47: 60 newline 61 %end nop .L15: movl -28(%ebp), %eax xorl %gs:20, %eax je .L25 call __stack_chk_fail_local .L25: leal -12(%ebp), %esp popl %ebx popl %esi popl %edi popl %ebp ret .LFE190: .section .rodata .align 32 .LC1: .byte 37 .string "Parameter must be a positive integer." .zero 217 .globl main main: .LFB189: 62 63 %integer highest, seed 64 65 prompt("Integer seed value: ") leal -284(%ebp), %edx movl $0, %eax movl $64, %ecx movl %edx, %edi rep stosl movb $20, -284(%ebp) movl $1702129225, -283(%ebp) movl $544367975, -279(%ebp) movl $1684366707, -275(%ebp) movw $30240, -271(%ebp) movb $97, -269(%ebp) leal -796(%ebp), %eax leal -284(%ebp), %edx movl $64, %ecx movl %eax, %edi movl %edx, %esi rep movsl .LBE49: subl $256, %esp movl %esp, %eax movl %eax, %edi leal -796(%ebp), %eax movl $64, %edx movl %eax, %esi movl %edx, %ecx rep movsl call _imp_PROMPT addl $256, %esp 66 read(seed) subl $12, %esp leal -820(%ebp), %eax pushl %eax call _imp_readint@PLT addl $16, %esp 67 68 %if seed < 0 %start movl -820(%ebp), %eax testl %eax, %eax jns .L36 .LBB50: nop .L33: 69 print string("Parameter must be a positive integer."); newline leal -284(%ebp), %eax leal .LC1@GOTOFF(%ebx), %edx movl $64, %ecx movl %eax, %edi movl %edx, %esi rep movsl leal -540(%ebp), %eax leal -284(%ebp), %edx movl $64, %ecx movl %eax, %edi movl %edx, %esi rep movsl leal -284(%ebp), %eax leal -540(%ebp), %edx movl $64, %ecx movl %eax, %edi movl %edx, %esi rep movsl .LBE50: .LBB51: .LBB52: subl $256, %esp movl %esp, %eax movl %eax, %edi leal -284(%ebp), %eax movl $64, %edx movl %eax, %esi movl %edx, %ecx rep movsl call _imp_printstring@PLT addl $256, %esp .LBE52: .LBE51: .LBB53: .LBB54: call _imp_newline@PLT movl $0, -816(%ebp) .LBE54: .LBE53: .LBB55: .LBB56: subl $12, %esp pushl -816(%ebp) call exit@PLT .L36: .LBE56: .LBE55: 70 %stop 71 %finish 72 73 highest = 0; show collatz length(seed-1, highest) movl $0, -824(%ebp) movl -820(%ebp), %eax leal -1(%eax), %ecx subl $8, %esp leal -808(%ebp), %eax leal -824(%ebp), %edx pushl %edx pushl %ecx movl %eax, %ecx call SHOWCOLLATZLENGTH.6025 addl $16, %esp 74 highest = 0; show collatz length(seed, highest) movl $0, -824(%ebp) movl -820(%ebp), %edx subl $8, %esp leal -808(%ebp), %eax leal -824(%ebp), %ecx pushl %ecx pushl %edx movl %eax, %ecx call SHOWCOLLATZLENGTH.6025 addl $16, %esp 75 highest = 0; show collatz length(seed+1, highest) movl $0, -824(%ebp) movl -820(%ebp), %eax leal 1(%eax), %ecx subl $8, %esp leal -808(%ebp), %eax leal -824(%ebp), %edx pushl %edx pushl %ecx movl %eax, %ecx call SHOWCOLLATZLENGTH.6025 addl $16, %esp movl $0, -812(%ebp) .LBB57: .LBB58: subl $12, %esp pushl -812(%ebp) call exit@PLT .LBE58: .LBE57: .LFE189: .section .rodata .LC6: .string "" .align 32 .LC0: .byte 19 .string "test-in/collatz.imp" .zero 235 ODDCOLLATZ.6029: .LFB192: 76 77 %endofprogram 50 Statements compiled