; 中间代码头部尾部参考clang -S -emit-llvm 生成结果

; ModuleID = 'func_test.c'
source_filename = "func_test.c"
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-pc-linux-gnu"

define dso_local i32 @add(i32 %0, i32 %1) #0 {
    %3 = alloca i32, align 4
    store i32 %0, i32* %3, align 4  ; alloca a

    %4 = alloca i32, align 4
    store i32 %1, i32* %4, align 4  ; alloca b

    %5 = load i32, i32* %3, align 4
    %6 = load i32, i32* %4, align 4
    %7 = add nsw i32 %5, %6 ; a+b
    %8 = sub nsw i32 %7, 1 ; a+b-1
    ret i32 %8  ; return a+b-1
}

define dso_local i32 @main() #0 {
    %1 = alloca i32, align 4
    %2 = alloca i32, align 4
    %3 = alloca i32, align 4

    store i32 3, i32* %1, align 4   ; a=3
    store i32 2, i32* %2, align 4   ; b=2
    store i32 5, i32* %3, align 4   ; c=5


    %4 = load i32, i32* %1, align 4
    %5 = load i32, i32* %2, align 4
    %6 = load i32, i32* %3, align 4

    %7 = call i32 @add(i32 %4, i32 %5)  ; add(a, b)
    %8 = add nsw i32 %6, %7 ; c+add(a,b)
    ret i32 %8
}

attributes #0 = { noinline nounwind optnone uwtable "frame-pointer"="all" "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }

!llvm.module.flags = !{!0, !1, !2, !3, !4}
!llvm.ident = !{!5}

!0 = !{i32 1, !"wchar_size", i32 4}
!1 = !{i32 7, !"PIC Level", i32 2}
!2 = !{i32 7, !"PIE Level", i32 2}
!3 = !{i32 7, !"uwtable", i32 1}
!4 = !{i32 7, !"frame-pointer", i32 2}
!5 = !{!"Ubuntu clang version 14.0.0-1ubuntu1.1"}