Skip to content

Instantly share code, notes, and snippets.

@hikari-no-yume
Created February 23, 2021 21:32
Show Gist options
  • Star 0 You must be signed in to star a gist
  • Fork 0 You must be signed in to fork a gist
  • Save hikari-no-yume/f2953c446e145edc7439c8cf3cafcfe8 to your computer and use it in GitHub Desktop.
Save hikari-no-yume/f2953c446e145edc7439c8cf3cafcfe8 to your computer and use it in GitHub Desktop.
What would C look like if it had already been compiled to LLVM IR and back again, but then you compiled it to LLVM IR and back again… again? (sequel to https://gist.github.com/hikari-no-yume/3cde016149d0309a80770c5eccd013ad, using https://github.com/JuliaComputing/llvm-cbe)
/* Provide Declarations */
#include <stdarg.h>
#include <setjmp.h>
#include <limits.h>
#include <stdint.h>
#include <math.h>
#ifndef __cplusplus
typedef unsigned char bool;
#endif
#if defined(__GNUC__)
#define __ATTRIBUTELIST__(x) __attribute__(x)
#else
#define __ATTRIBUTELIST__(x)
#endif
#ifdef _MSC_VER /* Can only support "linkonce" vars with GCC */
#define __attribute__(X)
#endif
/* Global Declarations */
/* Types Declarations */
/* Function definitions */
/* Types Definitions */
struct l_array_14_uint8_t {
uint8_t array[14];
};
/* External Global Variable Declarations */
/* Function Declarations */
uint32_t main(void) __ATTRIBUTELIST__((noinline, nothrow));
uint32_t printf(uint8_t*, ...);
/* Global Variable Definitions and Initialization */
static struct l_array_14_uint8_t _OC_str = { "hello, world\n" };
/* LLVM Intrinsic Builtin Function Bodies */
/* Function Bodies */
uint32_t main(void) {
uint32_t llvm_cbe_tmp__1;
llvm_cbe_tmp__1 = printf(((&_OC_str.array[((int64_t)UINT64_C(0))])));
return 0;
}
; ModuleID = 'hello-world.cbe.c'
source_filename = "hello-world.cbe.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"
%struct.l_array_14_uint8_t = type { [14 x i8] }
@_OC_str = internal global %struct.l_array_14_uint8_t { [14 x i8] c"hello, world\0A\00" }, align 1
; Function Attrs: noinline nounwind optnone uwtable
define dso_local i32 @main() #0 {
%1 = alloca i32, align 4
%2 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds (%struct.l_array_14_uint8_t, %struct.l_array_14_uint8_t* @_OC_str, i32 0, i32 0, i64 0))
store i32 %2, i32* %1, align 4
ret i32 0
}
declare dso_local i32 @printf(i8*, ...) #1
attributes #0 = { noinline nounwind optnone uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }
attributes #1 = { "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }
!llvm.module.flags = !{!0}
!llvm.ident = !{!1}
!0 = !{i32 1, !"wchar_size", i32 4}
!1 = !{!"clang version 10.0.0-4ubuntu1 "}
/* Provide Declarations */
#include <stdarg.h>
#include <setjmp.h>
#include <limits.h>
#include <stdint.h>
#include <math.h>
#ifndef __cplusplus
typedef unsigned char bool;
#endif
#if defined(__GNUC__)
#define __ATTRIBUTELIST__(x) __attribute__(x)
#else
#define __ATTRIBUTELIST__(x)
#endif
#ifdef _MSC_VER /* Can only support "linkonce" vars with GCC */
#define __attribute__(X)
#endif
/* Global Declarations */
/* Types Declarations */
struct l_struct_struct_OC_l_array_14_uint8_t;
/* Function definitions */
/* Types Definitions */
struct l_array_14_uint8_t {
uint8_t array[14];
};
struct l_struct_struct_OC_l_array_14_uint8_t {
struct l_array_14_uint8_t field0;
};
/* External Global Variable Declarations */
/* Function Declarations */
uint32_t main(void) __ATTRIBUTELIST__((noinline, nothrow));
uint32_t printf(uint8_t*, ...);
/* Global Variable Definitions and Initialization */
static struct l_struct_struct_OC_l_array_14_uint8_t _OC_str = { { "hello, world\n" } };
/* LLVM Intrinsic Builtin Function Bodies */
/* Function Bodies */
uint32_t main(void) {
uint32_t llvm_cbe_tmp__1; /* Address-exposed local */
uint32_t llvm_cbe_tmp__2;
llvm_cbe_tmp__2 = printf(((&_OC_str.field0.array[((int64_t)UINT64_C(0))])));
llvm_cbe_tmp__1 = llvm_cbe_tmp__2;
return 0;
}
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment