変遷の様子

0これが.ml

let a = 10 in
let rec f x = if x < 1 then 0 else x + (f (x - 1)) in
print_int (f a)

1こうなって

<let:let>(1:1:0-1:4:3)
<IDENT:a>(1:5:4-1:6:5)
<=:=>(1:7:6-1:8:7)
<INT:10>(1:9:8-1:11:10)
<in:in>(1:12:11-1:14:13)
<let:let>(2:1:14-2:4:17)
<rec:rec>(2:5:18-2:8:21)
<IDENT:f>(2:9:22-2:10:23)
<IDENT:x>(2:11:24-2:12:25)
<=:=>(2:13:26-2:14:27)
<if:if>(2:15:28-2:17:30)
<IDENT:x>(2:18:31-2:19:32)
<<:<>(2:20:33-2:21:34)
<INT:1>(2:22:35-2:23:36)
<then:then>(2:24:37-2:28:41)
<INT:0>(2:29:42-2:30:43)
<else:else>(2:31:44-2:35:48)
<IDENT:x>(2:36:49-2:37:50)
<+:+>(2:38:51-2:39:52)
<(:(>(2:40:53-2:41:54)
<IDENT:f>(2:41:54-2:42:55)
<(:(>(2:43:56-2:44:57)
<IDENT:x>(2:44:57-2:45:58)
<-:->(2:46:59-2:47:60)
<INT:1>(2:48:61-2:49:62)
<):)>(2:49:62-2:50:63)
<):)>(2:50:63-2:51:64)
<in:in>(2:52:65-2:54:67)
<IDENT:print_int>(3:1:68-3:10:77)
<(:(>(3:11:78-3:12:79)
<IDENT:f>(3:12:79-3:13:80)
<IDENT:a>(3:14:81-3:15:82)
<):)>(3:15:82-3:16:83)
<EOF:>(4:1:84-4:1:84)

2こうなって

AST for foo.ml:
-   Let (a) (1:1-3:15)
-   -   Int (1:9-1:11)
-   -   LetRec (fun f x) (2:1-3:15)
-   -   -   If (2:15-2:41)
-   -   -   -   Less (2:18-2:22)
-   -   -   -   -   VarRef (x) (2:18-2:19)
-   -   -   -   -   Int (2:22-2:23)
-   -   -   -   Int (2:29-2:30)
-   -   -   -   Add (2:36-2:41)
-   -   -   -   -   VarRef (x) (2:36-2:37)
-   -   -   -   -   Apply (2:41-2:48)
-   -   -   -   -   -   VarRef (f) (2:41-2:42)
-   -   -   -   -   -   Sub (2:44-2:48)
-   -   -   -   -   -   -   VarRef (x) (2:44-2:45)
-   -   -   -   -   -   -   Int (2:48-2:49)
-   -   -   Apply (3:1-3:15)
-   -   -   -   VarRef (print_int) (3:1-3:10)
-   -   -   -   Apply (3:12-3:15)
-   -   -   -   -   VarRef (f) (3:12-3:13)
-   -   -   -   -   VarRef (a) (3:14-3:15)

3こうなって

f$t2 = fun x$t3 ; type=int -> int
  BEGIN: body (f$t2)
  $k3 = int 1 ; type=int
  $k4 = binary < x$t3 $k3 ; type=bool
  $k13 = if $k4 ; type=int
    BEGIN: then
    $k5 = int 0 ; type=int
    END: then
    BEGIN: else
    $k9 = int 1 ; type=int
    $k10 = binary - x$t3 $k9 ; type=int
    $k11 = app f$t2 $k10 ; type=int
    $k12 = binary + x$t3 $k11 ; type=int
    END: else
  END: body (f$t2)

BEGIN: program
a$t1 = int 10 ; type=int
$k17 = app f$t2 a$t1 ; type=int
$k18 = appx print_int $k17 ; type=()
END: program

4こうなって.ll

; ModuleID = 'foo.ml'
source_filename = "foo.ml"
target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-apple-darwin15.6.0"

declare void @print_int(i64)

define i64 @"f$t2"(i64 %"x$t3") {
entry:
  %less = icmp slt i64 %"x$t3", 1
  br i1 %less, label %if.then, label %if.else

if.then:                                          ; preds = %entry
  br label %if.end

if.else:                                          ; preds = %entry
  %sub = sub i64 %"x$t3", 1
  %0 = call i64 @"f$t2"(i64 %sub)
  %add = add i64 %"x$t3", %0
  br label %if.end

if.end:                                           ; preds = %if.else, %if.then
  %if.merge = phi i64 [ 0, %if.then ], [ %add, %if.else ]
  ret i64 %if.merge
}

define i32 @main() {
entry:
  %0 = call i64 @"f$t2"(i64 10)
  call void @print_int(i64 %0)
  ret i32 0
}

5こうじゃ.s

	.section	__TEXT,__text,regular,pure_instructions
	.macosx_version_min 10, 11
	.globl	_f$t2
	.p2align	4, 0x90
_f$t2:
	.cfi_startproc
	pushq	%rbx
Lcfi0:
	.cfi_def_cfa_offset 16
Lcfi1:
	.cfi_offset %rbx, -16
	movq	%rdi, %rbx
	testq	%rbx, %rbx
	jle	LBB0_1
	leaq	-1(%rbx), %rdi
	callq	_f$t2
	addq	%rbx, %rax
	popq	%rbx
	retq
LBB0_1:
	xorl	%eax, %eax
	popq	%rbx
	retq
	.cfi_endproc

	.globl	_main
	.p2align	4, 0x90
_main:
	.cfi_startproc
	pushq	%rax
Lcfi2:
	.cfi_def_cfa_offset 16
	movl	$10, %edi
	callq	_f$t2
	movq	%rax, %rdi
	callq	_print_int
	xorl	%eax, %eax
	popq	%rcx
	retq
	.cfi_endproc


.subsections_via_symbols