Iterator chain vs. while loop comparison

diff-fulliter.s-while.s-.diff

2,3c2,3
< 	.file	"fulliter.0.rs"
< 	.section	.text._ZN4main20h34b4fa9d2be136ebeaaE,"ax",@progbits
---
> 	.file	"while.0.rs"
> 	.section	.text._ZN4main20h3118530cba082203eaaE,"ax",@progbits
5,6c5,6
< 	.type	_ZN4main20h34b4fa9d2be136ebeaaE,@function
< _ZN4main20h34b4fa9d2be136ebeaaE:
---
> 	.type	_ZN4main20h3118530cba082203eaaE,@function
> _ZN4main20h3118530cba082203eaaE:
17a18
> 	movq	$0, 64(%rsp)
22d22
< 	leal	1(%rax), %ecx
26c26
< 	leal	2(%rax), %edx
---
> 	leal	1(%rax), %ecx
30c30
< 	leal	3(%rax), %ecx
---
> 	leal	2(%rax), %ecx
32c32
< 	cvtsi2sdl	%edx, %xmm1
---
> 	cvtsi2sdl	%ecx, %xmm1
34c34
< 	leal	4(%rax), %edx
---
> 	leal	3(%rax), %ecx
38c38
< 	leal	5(%rax), %ecx
---
> 	leal	4(%rax), %ecx
40c40
< 	cvtsi2sdl	%edx, %xmm1
---
> 	cvtsi2sdl	%ecx, %xmm1
42c42
< 	leal	6(%rax), %edx
---
> 	leal	5(%rax), %ecx
46c46
< 	leal	7(%rax), %ecx
---
> 	leal	6(%rax), %ecx
48c48
< 	cvtsi2sdl	%edx, %xmm1
---
> 	cvtsi2sdl	%ecx, %xmm1
50c50
< 	addl	$8, %eax
---
> 	leal	7(%rax), %ecx
53a54
> 	addl	$8, %eax
61c62
< 	movups	_ZN4main15__STATIC_FMTSTR20h8ce82c07f6971712SaaE(%rip), %xmm0
---
> 	movups	_ZN4main15__STATIC_FMTSTR20h2631fad4cf02b14aNaaE(%rip), %xmm0
73c74
< 	.size	_ZN4main20h34b4fa9d2be136ebeaaE, .Ltmp1-_ZN4main20h34b4fa9d2be136ebeaaE
---
> 	.size	_ZN4main20h3118530cba082203eaaE, .Ltmp1-_ZN4main20h3118530cba082203eaaE
84c85
< 	leaq	_ZN4main20h34b4fa9d2be136ebeaaE(%rip), %rdi
---
> 	leaq	_ZN4main20h3118530cba082203eaaE(%rip), %rdi
92,94c93,95
< 	.type	str1197,@object
< 	.section	.rodata.str1197,"a",@progbits
< str1197:
---
> 	.type	str1063,@object
> 	.section	.rodata.str1063,"a",@progbits
> str1063:
96c97
< 	.size	str1197, 5
---
> 	.size	str1063, 5
98,100c99,101
< 	.type	str1198,@object
< 	.section	.rodata.str1198,"a",@progbits
< str1198:
---
> 	.type	str1064,@object
> 	.section	.rodata.str1064,"a",@progbits
> str1064:
102c103
< 	.size	str1198, 1
---
> 	.size	str1064, 1
104,105c105,106
< 	.type	ref1199,@object
< 	.section	.data.rel.ro.local.ref1199,"aw",@progbits
---
> 	.type	ref1065,@object
> 	.section	.data.rel.ro.local.ref1065,"aw",@progbits
107,108c108,109
< ref1199:
< 	.quad	str1197
---
> ref1065:
> 	.quad	str1063
110c111
< 	.quad	str1198
---
> 	.quad	str1064
112c113
< 	.size	ref1199, 32
---
> 	.size	ref1065, 32
114,115c115,116
< 	.type	_ZN4main15__STATIC_FMTSTR20h8ce82c07f6971712SaaE,@object
< 	.section	.data.rel.ro.local._ZN4main15__STATIC_FMTSTR20h8ce82c07f6971712SaaE,"aw",@progbits
---
> 	.type	_ZN4main15__STATIC_FMTSTR20h2631fad4cf02b14aNaaE,@object
> 	.section	.data.rel.ro.local._ZN4main15__STATIC_FMTSTR20h2631fad4cf02b14aNaaE,"aw",@progbits
117,118c118,119
< _ZN4main15__STATIC_FMTSTR20h8ce82c07f6971712SaaE:
< 	.quad	ref1199
---
> _ZN4main15__STATIC_FMTSTR20h2631fad4cf02b14aNaaE:
> 	.quad	ref1065
120c121
< 	.size	_ZN4main15__STATIC_FMTSTR20h8ce82c07f6971712SaaE, 16
---
> 	.size	_ZN4main15__STATIC_FMTSTR20h2631fad4cf02b14aNaaE, 16

fulliter.ll

; ModuleID = 'fulliter.0.rs'
target datalayout = "e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"

%str_slice = type { i8*, i64 }
%"2.core::fmt::Arguments" = type { { %str_slice*, i64 }, %"2.core::option::Option<&'static [core::fmt::rt::v1::Argument]>", { %"2.core::fmt::ArgumentV1"*, i64 } }
%"2.core::option::Option<&'static [core::fmt::rt::v1::Argument]>" = type { { %"2.core::fmt::rt::v1::Argument"*, i64 } }
%"2.core::fmt::rt::v1::Argument" = type { %"2.core::fmt::rt::v1::Position", %"2.core::fmt::rt::v1::FormatSpec" }
%"2.core::fmt::rt::v1::Position" = type { i64, [0 x i64], [1 x i64] }
%"2.core::fmt::rt::v1::FormatSpec" = type { i32, i8, i32, %"2.core::fmt::rt::v1::Count", %"2.core::fmt::rt::v1::Count" }
%"2.core::fmt::rt::v1::Count" = type { i64, [0 x i64], [1 x i64] }
%"2.core::fmt::ArgumentV1" = type { %"2.core::fmt::Void"*, i8 (%"2.core::fmt::Void"*, %"2.core::fmt::Formatter"*)* }
%"2.core::fmt::Void" = type {}
%"2.core::fmt::Formatter" = type { i32, i32, i8, %"2.core::option::Option<usize>", %"2.core::option::Option<usize>", { i8*, void (i8*)** }, %"2.core::slice::Iter<core::fmt::ArgumentV1>", { %"2.core::fmt::ArgumentV1"*, i64 } }
%"2.core::option::Option<usize>" = type { i64, [0 x i64], [1 x i64] }
%"2.core::slice::Iter<core::fmt::ArgumentV1>" = type { %"2.core::fmt::ArgumentV1"*, %"2.core::fmt::ArgumentV1"*, %"2.core::marker::PhantomData<&'static core::fmt::ArgumentV1>" }
%"2.core::marker::PhantomData<&'static core::fmt::ArgumentV1>" = type {}

@str1197 = internal constant [5 x i8] c"Sum: "
@str1198 = internal constant [1 x i8] c"\0A"
@ref1199 = internal unnamed_addr constant [2 x %str_slice] [%str_slice { i8* getelementptr inbounds ([5 x i8]* @str1197, i32 0, i32 0), i64 5 }, %str_slice { i8* getelementptr inbounds ([1 x i8]* @str1198, i32 0, i32 0), i64 1 }]
@_ZN4main15__STATIC_FMTSTR20h8ce82c07f6971712SaaE = internal unnamed_addr constant { %str_slice*, i64 } { %str_slice* getelementptr inbounds ([2 x %str_slice]* @ref1199, i32 0, i32 0), i64 2 }

; Function Attrs: uwtable
define internal void @_ZN4main20h34b4fa9d2be136ebeaaE() unnamed_addr #0 {
entry-block:
  %sum = alloca double, align 8
  %0 = alloca %"2.core::fmt::Arguments", align 8
  %1 = alloca [1 x %"2.core::fmt::ArgumentV1"], align 8
  %2 = bitcast double* %sum to i8*
  call void @llvm.lifetime.start(i64 8, i8* %2)
  br label %match_case.i

match_case.i:                                     ; preds = %match_case.i, %entry-block
  %accum.04.i = phi double [ 0.000000e+00, %entry-block ], [ %19, %match_case.i ]
  %3 = phi i32 [ 0, %entry-block ], [ %18, %match_case.i ]
  %4 = add nuw nsw i32 %3, 1
  %phitmp.i.i = sitofp i32 %3 to double
  %5 = fadd double %accum.04.i, %phitmp.i.i
  %6 = add nuw nsw i32 %4, 1
  %phitmp.i.i.1 = sitofp i32 %4 to double
  %7 = fadd double %5, %phitmp.i.i.1
  %8 = add nuw nsw i32 %6, 1
  %phitmp.i.i.2 = sitofp i32 %6 to double
  %9 = fadd double %7, %phitmp.i.i.2
  %10 = add nuw nsw i32 %8, 1
  %phitmp.i.i.3 = sitofp i32 %8 to double
  %11 = fadd double %9, %phitmp.i.i.3
  %12 = add nuw nsw i32 %10, 1
  %phitmp.i.i.4 = sitofp i32 %10 to double
  %13 = fadd double %11, %phitmp.i.i.4
  %14 = add nuw nsw i32 %12, 1
  %phitmp.i.i.5 = sitofp i32 %12 to double
  %15 = fadd double %13, %phitmp.i.i.5
  %16 = add nuw nsw i32 %14, 1
  %phitmp.i.i.6 = sitofp i32 %14 to double
  %17 = fadd double %15, %phitmp.i.i.6
  %18 = add nuw nsw i32 %16, 1
  %phitmp.i.i.7 = sitofp i32 %16 to double
  %19 = fadd double %17, %phitmp.i.i.7
  %exitcond.i.7 = icmp eq i32 %18, 100000000
  br i1 %exitcond.i.7, label %_ZN4iter8Iterator4fold21h16132946566178862456E.exit, label %match_case.i

_ZN4iter8Iterator4fold21h16132946566178862456E.exit: ; preds = %match_case.i
  %.lcssa = phi double [ %19, %match_case.i ]
  store double %.lcssa, double* %sum, align 8
  %20 = bitcast %"2.core::fmt::Arguments"* %0 to i8*
  call void @llvm.lifetime.start(i64 48, i8* %20)
  %21 = bitcast [1 x %"2.core::fmt::ArgumentV1"]* %1 to i8*
  call void @llvm.lifetime.start(i64 16, i8* %21)
  %22 = getelementptr inbounds [1 x %"2.core::fmt::ArgumentV1"]* %1, i64 0, i64 0
  %23 = getelementptr inbounds [1 x %"2.core::fmt::ArgumentV1"]* %1, i64 0, i64 0, i32 1
  store i8 (%"2.core::fmt::Void"*, %"2.core::fmt::Formatter"*)* bitcast (i8 (double*, %"2.core::fmt::Formatter"*)* @_ZN3fmt11f64.Display3fmt20hfda565c93058390eARJE to i8 (%"2.core::fmt::Void"*, %"2.core::fmt::Formatter"*)*), i8 (%"2.core::fmt::Void"*, %"2.core::fmt::Formatter"*)** %23, align 8, !alias.scope !0, !noalias !3
  %24 = bitcast [1 x %"2.core::fmt::ArgumentV1"]* %1 to double**
  store double* %sum, double** %24, align 8, !alias.scope !0, !noalias !3
  call void @llvm.memcpy.p0i8.p0i8.i64(i8* %20, i8* bitcast ({ %str_slice*, i64 }* @_ZN4main15__STATIC_FMTSTR20h8ce82c07f6971712SaaE to i8*), i64 16, i32 8, i1 false) #3, !alias.scope !5, !noalias !9
  %25 = getelementptr inbounds %"2.core::fmt::Arguments"* %0, i64 0, i32 1
  %26 = bitcast %"2.core::option::Option<&'static [core::fmt::rt::v1::Argument]>"* %25 to i8*
  call void @llvm.memset.p0i8.i64(i8* %26, i8 0, i64 16, i32 8, i1 false) #3, !alias.scope !11, !noalias !12
  %27 = getelementptr inbounds %"2.core::fmt::Arguments"* %0, i64 0, i32 2, i32 0
  store %"2.core::fmt::ArgumentV1"* %22, %"2.core::fmt::ArgumentV1"** %27, align 8
  %28 = getelementptr inbounds %"2.core::fmt::Arguments"* %0, i64 0, i32 2, i32 1
  store i64 1, i64* %28, align 8
  call void @_ZN2io5stdio6_print20h64960a4013ef06515TgE(%"2.core::fmt::Arguments"* noalias nocapture dereferenceable(48) %0)
  call void @llvm.lifetime.end(i64 48, i8* %20)
  call void @llvm.lifetime.end(i64 16, i8* %21)
  call void @llvm.lifetime.end(i64 8, i8* %2)
  ret void
}

; Function Attrs: nounwind
declare void @llvm.lifetime.start(i64, i8* nocapture) unnamed_addr #1

; Function Attrs: nounwind
declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture readonly, i64, i32, i1) unnamed_addr #1

; Function Attrs: nounwind
declare void @llvm.lifetime.end(i64, i8* nocapture) unnamed_addr #1

declare void @_ZN2io5stdio6_print20h64960a4013ef06515TgE(%"2.core::fmt::Arguments"* noalias nocapture dereferenceable(48)) unnamed_addr #2

declare i8 @_ZN3fmt11f64.Display3fmt20hfda565c93058390eARJE(double* noalias readonly dereferenceable(8), %"2.core::fmt::Formatter"* noalias dereferenceable(96)) unnamed_addr #2

define i64 @main(i64, i8**) unnamed_addr #2 {
top:
  %2 = tail call i64 @_ZN2rt10lang_start20h787996d0ae650185OlwE(i8* bitcast (void ()* @_ZN4main20h34b4fa9d2be136ebeaaE to i8*), i64 %0, i8** %1)
  ret i64 %2
}

declare i64 @_ZN2rt10lang_start20h787996d0ae650185OlwE(i8*, i64, i8**) unnamed_addr #2

; Function Attrs: nounwind
declare void @llvm.memset.p0i8.i64(i8* nocapture, i8, i64, i32, i1) #3

attributes #0 = { uwtable "split-stack" }
attributes #1 = { nounwind "split-stack" }
attributes #2 = { "split-stack" }
attributes #3 = { nounwind }

!0 = !{!1}
!1 = distinct !{!1, !2, !"_ZN3fmt24ArgumentV1$LT$$u27$a$GT$3new20h2345393963723667609E: argument 0"}
!2 = distinct !{!2, !"_ZN3fmt24ArgumentV1$LT$$u27$a$GT$3new20h2345393963723667609E"}
!3 = !{!4}
!4 = distinct !{!4, !2, !"_ZN3fmt24ArgumentV1$LT$$u27$a$GT$3new20h2345393963723667609E: argument 1"}
!5 = !{!6, !8}
!6 = distinct !{!6, !7, !"_ZN3fmt23Arguments$LT$$u27$a$GT$6new_v120h4f5ff6b205ba2f42q8IE: argument 0"}
!7 = distinct !{!7, !"_ZN3fmt23Arguments$LT$$u27$a$GT$6new_v120h4f5ff6b205ba2f42q8IE"}
!8 = distinct !{!8, !7, !"_ZN3fmt23Arguments$LT$$u27$a$GT$6new_v120h4f5ff6b205ba2f42q8IE: argument 1"}
!9 = !{!10}
!10 = distinct !{!10, !7, !"_ZN3fmt23Arguments$LT$$u27$a$GT$6new_v120h4f5ff6b205ba2f42q8IE: argument 2"}
!11 = !{!6}
!12 = !{!8, !10}

fulliter.rs

fn main() {
    let sum = (0..100_000_000).map(|x| x as f64).fold(0.0, |acc, n| acc + n);
    println!("Sum: {}", sum);
}

fulliter.s

	.text
	.file	"fulliter.0.rs"
	.section	.text._ZN4main20h34b4fa9d2be136ebeaaE,"ax",@progbits
	.align	16, 0x90
	.type	_ZN4main20h34b4fa9d2be136ebeaaE,@function
_ZN4main20h34b4fa9d2be136ebeaaE:
	.cfi_startproc
	cmpq	%fs:112, %rsp
	ja	.LBB0_2
	movabsq	$72, %r10
	movabsq	$0, %r11
	callq	__morestack
	retq
.LBB0_2:
	subq	$72, %rsp
.Ltmp0:
	.cfi_def_cfa_offset 80
	xorl	%eax, %eax
	xorps	%xmm0, %xmm0
	.align	16, 0x90
.LBB0_3:
	leal	1(%rax), %ecx
	xorps	%xmm1, %xmm1
	cvtsi2sdl	%eax, %xmm1
	addsd	%xmm0, %xmm1
	leal	2(%rax), %edx
	xorps	%xmm0, %xmm0
	cvtsi2sdl	%ecx, %xmm0
	addsd	%xmm1, %xmm0
	leal	3(%rax), %ecx
	xorps	%xmm1, %xmm1
	cvtsi2sdl	%edx, %xmm1
	addsd	%xmm0, %xmm1
	leal	4(%rax), %edx
	xorps	%xmm0, %xmm0
	cvtsi2sdl	%ecx, %xmm0
	addsd	%xmm1, %xmm0
	leal	5(%rax), %ecx
	xorps	%xmm1, %xmm1
	cvtsi2sdl	%edx, %xmm1
	addsd	%xmm0, %xmm1
	leal	6(%rax), %edx
	xorps	%xmm0, %xmm0
	cvtsi2sdl	%ecx, %xmm0
	addsd	%xmm1, %xmm0
	leal	7(%rax), %ecx
	xorps	%xmm1, %xmm1
	cvtsi2sdl	%edx, %xmm1
	addsd	%xmm0, %xmm1
	addl	$8, %eax
	xorps	%xmm0, %xmm0
	cvtsi2sdl	%ecx, %xmm0
	addsd	%xmm1, %xmm0
	cmpl	$100000000, %eax
	jne	.LBB0_3
	movsd	%xmm0, 64(%rsp)
	movq	_ZN3fmt11f64.Display3fmt20hfda565c93058390eARJE@GOTPCREL(%rip), %rax
	movq	%rax, 8(%rsp)
	leaq	64(%rsp), %rax
	movq	%rax, (%rsp)
	movups	_ZN4main15__STATIC_FMTSTR20h8ce82c07f6971712SaaE(%rip), %xmm0
	movaps	%xmm0, 16(%rsp)
	xorps	%xmm0, %xmm0
	movaps	%xmm0, 32(%rsp)
	leaq	(%rsp), %rax
	movq	%rax, 48(%rsp)
	movq	$1, 56(%rsp)
	leaq	16(%rsp), %rdi
	callq	_ZN2io5stdio6_print20h64960a4013ef06515TgE@PLT
	addq	$72, %rsp
	retq
.Ltmp1:
	.size	_ZN4main20h34b4fa9d2be136ebeaaE, .Ltmp1-_ZN4main20h34b4fa9d2be136ebeaaE
	.cfi_endproc

	.section	.text.main,"ax",@progbits
	.globl	main
	.align	16, 0x90
	.type	main,@function
main:
	.cfi_startproc
	movq	%rsi, %rax
	movq	%rdi, %rcx
	leaq	_ZN4main20h34b4fa9d2be136ebeaaE(%rip), %rdi
	movq	%rcx, %rsi
	movq	%rax, %rdx
	jmp	_ZN2rt10lang_start20h787996d0ae650185OlwE@PLT
.Ltmp2:
	.size	main, .Ltmp2-main
	.cfi_endproc

	.type	str1197,@object
	.section	.rodata.str1197,"a",@progbits
str1197:
	.ascii	"Sum: "
	.size	str1197, 5

	.type	str1198,@object
	.section	.rodata.str1198,"a",@progbits
str1198:
	.byte	10
	.size	str1198, 1

	.type	ref1199,@object
	.section	.data.rel.ro.local.ref1199,"aw",@progbits
	.align	16
ref1199:
	.quad	str1197
	.quad	5
	.quad	str1198
	.quad	1
	.size	ref1199, 32

	.type	_ZN4main15__STATIC_FMTSTR20h8ce82c07f6971712SaaE,@object
	.section	.data.rel.ro.local._ZN4main15__STATIC_FMTSTR20h8ce82c07f6971712SaaE,"aw",@progbits
	.align	8
_ZN4main15__STATIC_FMTSTR20h8ce82c07f6971712SaaE:
	.quad	ref1199
	.quad	2
	.size	_ZN4main15__STATIC_FMTSTR20h8ce82c07f6971712SaaE, 16


	.section	".note.GNU-stack","",@progbits

while.ll

; ModuleID = 'while.0.rs'
target datalayout = "e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"

%str_slice = type { i8*, i64 }
%"2.core::fmt::Arguments" = type { { %str_slice*, i64 }, %"2.core::option::Option<&'static [core::fmt::rt::v1::Argument]>", { %"2.core::fmt::ArgumentV1"*, i64 } }
%"2.core::option::Option<&'static [core::fmt::rt::v1::Argument]>" = type { { %"2.core::fmt::rt::v1::Argument"*, i64 } }
%"2.core::fmt::rt::v1::Argument" = type { %"2.core::fmt::rt::v1::Position", %"2.core::fmt::rt::v1::FormatSpec" }
%"2.core::fmt::rt::v1::Position" = type { i64, [0 x i64], [1 x i64] }
%"2.core::fmt::rt::v1::FormatSpec" = type { i32, i8, i32, %"2.core::fmt::rt::v1::Count", %"2.core::fmt::rt::v1::Count" }
%"2.core::fmt::rt::v1::Count" = type { i64, [0 x i64], [1 x i64] }
%"2.core::fmt::ArgumentV1" = type { %"2.core::fmt::Void"*, i8 (%"2.core::fmt::Void"*, %"2.core::fmt::Formatter"*)* }
%"2.core::fmt::Void" = type {}
%"2.core::fmt::Formatter" = type { i32, i32, i8, %"2.core::option::Option<usize>", %"2.core::option::Option<usize>", { i8*, void (i8*)** }, %"2.core::slice::Iter<core::fmt::ArgumentV1>", { %"2.core::fmt::ArgumentV1"*, i64 } }
%"2.core::option::Option<usize>" = type { i64, [0 x i64], [1 x i64] }
%"2.core::slice::Iter<core::fmt::ArgumentV1>" = type { %"2.core::fmt::ArgumentV1"*, %"2.core::fmt::ArgumentV1"*, %"2.core::marker::PhantomData<&'static core::fmt::ArgumentV1>" }
%"2.core::marker::PhantomData<&'static core::fmt::ArgumentV1>" = type {}

@str1063 = internal constant [5 x i8] c"Sum: "
@str1064 = internal constant [1 x i8] c"\0A"
@ref1065 = internal unnamed_addr constant [2 x %str_slice] [%str_slice { i8* getelementptr inbounds ([5 x i8]* @str1063, i32 0, i32 0), i64 5 }, %str_slice { i8* getelementptr inbounds ([1 x i8]* @str1064, i32 0, i32 0), i64 1 }]
@_ZN4main15__STATIC_FMTSTR20h2631fad4cf02b14aNaaE = internal unnamed_addr constant { %str_slice*, i64 } { %str_slice* getelementptr inbounds ([2 x %str_slice]* @ref1065, i32 0, i32 0), i64 2 }

; Function Attrs: uwtable
define internal void @_ZN4main20h3118530cba082203eaaE() unnamed_addr #0 {
entry-block:
  %sum = alloca double, align 8
  %0 = alloca %"2.core::fmt::Arguments", align 8
  %1 = alloca [1 x %"2.core::fmt::ArgumentV1"], align 8
  %2 = bitcast double* %sum to i8*
  call void @llvm.lifetime.start(i64 8, i8* %2)
  store double 0.000000e+00, double* %sum, align 8
  br label %while_body

while_exit:                                       ; preds = %while_body
  %.lcssa = phi double [ %35, %while_body ]
  store double %.lcssa, double* %sum, align 8
  %3 = bitcast %"2.core::fmt::Arguments"* %0 to i8*
  call void @llvm.lifetime.start(i64 48, i8* %3)
  %4 = bitcast [1 x %"2.core::fmt::ArgumentV1"]* %1 to i8*
  call void @llvm.lifetime.start(i64 16, i8* %4)
  %5 = getelementptr inbounds [1 x %"2.core::fmt::ArgumentV1"]* %1, i64 0, i64 0
  %6 = getelementptr inbounds [1 x %"2.core::fmt::ArgumentV1"]* %1, i64 0, i64 0, i32 1
  store i8 (%"2.core::fmt::Void"*, %"2.core::fmt::Formatter"*)* bitcast (i8 (double*, %"2.core::fmt::Formatter"*)* @_ZN3fmt11f64.Display3fmt20hfda565c93058390eARJE to i8 (%"2.core::fmt::Void"*, %"2.core::fmt::Formatter"*)*), i8 (%"2.core::fmt::Void"*, %"2.core::fmt::Formatter"*)** %6, align 8, !alias.scope !0, !noalias !3
  %7 = bitcast [1 x %"2.core::fmt::ArgumentV1"]* %1 to double**
  store double* %sum, double** %7, align 8, !alias.scope !0, !noalias !3
  call void @llvm.memcpy.p0i8.p0i8.i64(i8* %3, i8* bitcast ({ %str_slice*, i64 }* @_ZN4main15__STATIC_FMTSTR20h2631fad4cf02b14aNaaE to i8*), i64 16, i32 8, i1 false) #3, !alias.scope !5, !noalias !9
  %8 = getelementptr inbounds %"2.core::fmt::Arguments"* %0, i64 0, i32 1
  %9 = bitcast %"2.core::option::Option<&'static [core::fmt::rt::v1::Argument]>"* %8 to i8*
  call void @llvm.memset.p0i8.i64(i8* %9, i8 0, i64 16, i32 8, i1 false) #3, !alias.scope !11, !noalias !12
  %10 = getelementptr inbounds %"2.core::fmt::Arguments"* %0, i64 0, i32 2, i32 0
  store %"2.core::fmt::ArgumentV1"* %5, %"2.core::fmt::ArgumentV1"** %10, align 8
  %11 = getelementptr inbounds %"2.core::fmt::Arguments"* %0, i64 0, i32 2, i32 1
  store i64 1, i64* %11, align 8
  call void @_ZN2io5stdio6_print20h64960a4013ef06515TgE(%"2.core::fmt::Arguments"* noalias nocapture dereferenceable(48) %0)
  call void @llvm.lifetime.end(i64 48, i8* %3)
  call void @llvm.lifetime.end(i64 16, i8* %4)
  call void @llvm.lifetime.end(i64 8, i8* %2)
  ret void

while_body:                                       ; preds = %while_body, %entry-block
  %12 = phi double [ 0.000000e+00, %entry-block ], [ %35, %while_body ]
  %i.01 = phi i32 [ 0, %entry-block ], [ %36, %while_body ]
  %13 = sitofp i32 %i.01 to double
  %14 = fadd double %13, %12
  %15 = add nuw nsw i32 %i.01, 1
  %16 = sitofp i32 %15 to double
  %17 = fadd double %16, %14
  %18 = add nuw nsw i32 %15, 1
  %19 = sitofp i32 %18 to double
  %20 = fadd double %19, %17
  %21 = add nuw nsw i32 %18, 1
  %22 = sitofp i32 %21 to double
  %23 = fadd double %22, %20
  %24 = add nuw nsw i32 %21, 1
  %25 = sitofp i32 %24 to double
  %26 = fadd double %25, %23
  %27 = add nuw nsw i32 %24, 1
  %28 = sitofp i32 %27 to double
  %29 = fadd double %28, %26
  %30 = add nuw nsw i32 %27, 1
  %31 = sitofp i32 %30 to double
  %32 = fadd double %31, %29
  %33 = add nuw nsw i32 %30, 1
  %34 = sitofp i32 %33 to double
  %35 = fadd double %34, %32
  %36 = add nuw nsw i32 %33, 1
  %exitcond.7 = icmp eq i32 %36, 100000000
  br i1 %exitcond.7, label %while_exit, label %while_body
}

; Function Attrs: nounwind
declare void @llvm.lifetime.start(i64, i8* nocapture) unnamed_addr #1

declare void @_ZN2io5stdio6_print20h64960a4013ef06515TgE(%"2.core::fmt::Arguments"* noalias nocapture dereferenceable(48)) unnamed_addr #2

; Function Attrs: nounwind
declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture readonly, i64, i32, i1) unnamed_addr #1

; Function Attrs: nounwind
declare void @llvm.lifetime.end(i64, i8* nocapture) unnamed_addr #1

declare i8 @_ZN3fmt11f64.Display3fmt20hfda565c93058390eARJE(double* noalias readonly dereferenceable(8), %"2.core::fmt::Formatter"* noalias dereferenceable(96)) unnamed_addr #2

define i64 @main(i64, i8**) unnamed_addr #2 {
top:
  %2 = tail call i64 @_ZN2rt10lang_start20h787996d0ae650185OlwE(i8* bitcast (void ()* @_ZN4main20h3118530cba082203eaaE to i8*), i64 %0, i8** %1)
  ret i64 %2
}

declare i64 @_ZN2rt10lang_start20h787996d0ae650185OlwE(i8*, i64, i8**) unnamed_addr #2

; Function Attrs: nounwind
declare void @llvm.memset.p0i8.i64(i8* nocapture, i8, i64, i32, i1) #3

attributes #0 = { uwtable "split-stack" }
attributes #1 = { nounwind "split-stack" }
attributes #2 = { "split-stack" }
attributes #3 = { nounwind }

!0 = !{!1}
!1 = distinct !{!1, !2, !"_ZN3fmt24ArgumentV1$LT$$u27$a$GT$3new21h12120103399187833025E: argument 0"}
!2 = distinct !{!2, !"_ZN3fmt24ArgumentV1$LT$$u27$a$GT$3new21h12120103399187833025E"}
!3 = !{!4}
!4 = distinct !{!4, !2, !"_ZN3fmt24ArgumentV1$LT$$u27$a$GT$3new21h12120103399187833025E: argument 1"}
!5 = !{!6, !8}
!6 = distinct !{!6, !7, !"_ZN3fmt23Arguments$LT$$u27$a$GT$6new_v120h4f5ff6b205ba2f42q8IE: argument 0"}
!7 = distinct !{!7, !"_ZN3fmt23Arguments$LT$$u27$a$GT$6new_v120h4f5ff6b205ba2f42q8IE"}
!8 = distinct !{!8, !7, !"_ZN3fmt23Arguments$LT$$u27$a$GT$6new_v120h4f5ff6b205ba2f42q8IE: argument 1"}
!9 = !{!10}
!10 = distinct !{!10, !7, !"_ZN3fmt23Arguments$LT$$u27$a$GT$6new_v120h4f5ff6b205ba2f42q8IE: argument 2"}
!11 = !{!6}
!12 = !{!8, !10}

while.rs

fn main() {
    let mut sum = 0.0;
    let mut i = 0;
    while i < 100_000_000 {
        sum += i as f64;
        i += 1;
    }
    println!("Sum: {}", sum);
}

while.s

	.text
	.file	"while.0.rs"
	.section	.text._ZN4main20h3118530cba082203eaaE,"ax",@progbits
	.align	16, 0x90
	.type	_ZN4main20h3118530cba082203eaaE,@function
_ZN4main20h3118530cba082203eaaE:
	.cfi_startproc
	cmpq	%fs:112, %rsp
	ja	.LBB0_2
	movabsq	$72, %r10
	movabsq	$0, %r11
	callq	__morestack
	retq
.LBB0_2:
	subq	$72, %rsp
.Ltmp0:
	.cfi_def_cfa_offset 80
	movq	$0, 64(%rsp)
	xorl	%eax, %eax
	xorps	%xmm0, %xmm0
	.align	16, 0x90
.LBB0_3:
	xorps	%xmm1, %xmm1
	cvtsi2sdl	%eax, %xmm1
	addsd	%xmm0, %xmm1
	leal	1(%rax), %ecx
	xorps	%xmm0, %xmm0
	cvtsi2sdl	%ecx, %xmm0
	addsd	%xmm1, %xmm0
	leal	2(%rax), %ecx
	xorps	%xmm1, %xmm1
	cvtsi2sdl	%ecx, %xmm1
	addsd	%xmm0, %xmm1
	leal	3(%rax), %ecx
	xorps	%xmm0, %xmm0
	cvtsi2sdl	%ecx, %xmm0
	addsd	%xmm1, %xmm0
	leal	4(%rax), %ecx
	xorps	%xmm1, %xmm1
	cvtsi2sdl	%ecx, %xmm1
	addsd	%xmm0, %xmm1
	leal	5(%rax), %ecx
	xorps	%xmm0, %xmm0
	cvtsi2sdl	%ecx, %xmm0
	addsd	%xmm1, %xmm0
	leal	6(%rax), %ecx
	xorps	%xmm1, %xmm1
	cvtsi2sdl	%ecx, %xmm1
	addsd	%xmm0, %xmm1
	leal	7(%rax), %ecx
	xorps	%xmm0, %xmm0
	cvtsi2sdl	%ecx, %xmm0
	addsd	%xmm1, %xmm0
	addl	$8, %eax
	cmpl	$100000000, %eax
	jne	.LBB0_3
	movsd	%xmm0, 64(%rsp)
	movq	_ZN3fmt11f64.Display3fmt20hfda565c93058390eARJE@GOTPCREL(%rip), %rax
	movq	%rax, 8(%rsp)
	leaq	64(%rsp), %rax
	movq	%rax, (%rsp)
	movups	_ZN4main15__STATIC_FMTSTR20h2631fad4cf02b14aNaaE(%rip), %xmm0
	movaps	%xmm0, 16(%rsp)
	xorps	%xmm0, %xmm0
	movaps	%xmm0, 32(%rsp)
	leaq	(%rsp), %rax
	movq	%rax, 48(%rsp)
	movq	$1, 56(%rsp)
	leaq	16(%rsp), %rdi
	callq	_ZN2io5stdio6_print20h64960a4013ef06515TgE@PLT
	addq	$72, %rsp
	retq
.Ltmp1:
	.size	_ZN4main20h3118530cba082203eaaE, .Ltmp1-_ZN4main20h3118530cba082203eaaE
	.cfi_endproc

	.section	.text.main,"ax",@progbits
	.globl	main
	.align	16, 0x90
	.type	main,@function
main:
	.cfi_startproc
	movq	%rsi, %rax
	movq	%rdi, %rcx
	leaq	_ZN4main20h3118530cba082203eaaE(%rip), %rdi
	movq	%rcx, %rsi
	movq	%rax, %rdx
	jmp	_ZN2rt10lang_start20h787996d0ae650185OlwE@PLT
.Ltmp2:
	.size	main, .Ltmp2-main
	.cfi_endproc

	.type	str1063,@object
	.section	.rodata.str1063,"a",@progbits
str1063:
	.ascii	"Sum: "
	.size	str1063, 5

	.type	str1064,@object
	.section	.rodata.str1064,"a",@progbits
str1064:
	.byte	10
	.size	str1064, 1

	.type	ref1065,@object
	.section	.data.rel.ro.local.ref1065,"aw",@progbits
	.align	16
ref1065:
	.quad	str1063
	.quad	5
	.quad	str1064
	.quad	1
	.size	ref1065, 32

	.type	_ZN4main15__STATIC_FMTSTR20h2631fad4cf02b14aNaaE,@object
	.section	.data.rel.ro.local._ZN4main15__STATIC_FMTSTR20h2631fad4cf02b14aNaaE,"aw",@progbits
	.align	8
_ZN4main15__STATIC_FMTSTR20h2631fad4cf02b14aNaaE:
	.quad	ref1065
	.quad	2
	.size	_ZN4main15__STATIC_FMTSTR20h2631fad4cf02b14aNaaE, 16


	.section	".note.GNU-stack","",@progbits