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@mikeash mikeash/test.c
Created Jul 2, 2017

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ARM64 normal and variadic calling conventions
// xcrun -sdk iphoneos clang -O3 -arch arm64 -S test.c
#import <stdarg.h>
#import <stdio.h>
void normal(int a, int b, int c, int d, int e, int f, int g, int h) {
printf("%d %d %d %d %d %d %d %d", a, b, c, d, e, f, g, h);
}
void normal_target(int a, int b, int c, int d, int e, int f, int g, int h);
void call_normal() {
normal_target(1, 2, 3, 4, 5, 6, 7, 8);
}
void vararg(int a, ...) {
va_list args;
va_start(args, a);
int b = va_arg(args, int);
int c = va_arg(args, int);
int d = va_arg(args, int);
int e = va_arg(args, int);
int f = va_arg(args, int);
int g = va_arg(args, int);
int h = va_arg(args, int);
printf("%d %d %d %d %d %d %d %d", a, b, c, d, e, f, g, h);
}
void vararg_target(int a, ...);
void call_vararg() {
vararg_target(1, 2, 3, 4, 5, 6, 7, 8);
}
.section __TEXT,__text,regular,pure_instructions
.ios_version_min 10, 3
.globl _normal
.p2align 2
_normal: ; @normal
; BB#0:
sub sp, sp, #80 ; =80
stp x29, x30, [sp, #64] ; 8-byte Folded Spill
add x29, sp, #64 ; =64
; kill: %W7<def> %W7<kill> %X7<def>
; kill: %W6<def> %W6<kill> %X6<def>
; kill: %W5<def> %W5<kill> %X5<def>
; kill: %W4<def> %W4<kill> %X4<def>
; kill: %W3<def> %W3<kill> %X3<def>
; kill: %W2<def> %W2<kill> %X2<def>
; kill: %W1<def> %W1<kill> %X1<def>
; kill: %W0<def> %W0<kill> %X0<def>
stp x6, x7, [sp, #48]
stp x4, x5, [sp, #32]
stp x2, x3, [sp, #16]
Lloh0:
adrp x8, L_.str@PAGE
Lloh1:
add x8, x8, L_.str@PAGEOFF
stp x0, x1, [sp]
mov x0, x8
bl _printf
ldp x29, x30, [sp, #64] ; 8-byte Folded Reload
add sp, sp, #80 ; =80
ret
.loh AdrpAdd Lloh0, Lloh1
.globl _call_normal
.p2align 2
_call_normal: ; @call_normal
; BB#0:
orr w0, wzr, #0x1
orr w1, wzr, #0x2
orr w2, wzr, #0x3
orr w3, wzr, #0x4
mov w4, #5
orr w5, wzr, #0x6
orr w6, wzr, #0x7
orr w7, wzr, #0x8
b _normal_target
.globl _vararg
.p2align 2
_vararg: ; @vararg
; BB#0:
sub sp, sp, #96 ; =96
stp x29, x30, [sp, #80] ; 8-byte Folded Spill
add x29, sp, #80 ; =80
; kill: %W0<def> %W0<kill> %X0<def>
add x8, x29, #16 ; =16
stur x8, [x29, #-8]
orr x8, x8, #0x8
stur x8, [x29, #-8]
ldr w9, [x29, #16]
add x10, x8, #8 ; =8
stur x10, [x29, #-8]
ldr w8, [x8]
add x11, x10, #8 ; =8
stur x11, [x29, #-8]
ldr w10, [x10]
add x12, x11, #8 ; =8
stur x12, [x29, #-8]
ldr w11, [x11]
add x13, x12, #8 ; =8
stur x13, [x29, #-8]
ldr w12, [x12]
add x14, x13, #8 ; =8
stur x14, [x29, #-8]
ldr w13, [x13]
add x15, x14, #8 ; =8
stur x15, [x29, #-8]
ldr w14, [x14]
stp x13, x14, [sp, #48]
stp x11, x12, [sp, #32]
stp x8, x10, [sp, #16]
Lloh2:
adrp x8, L_.str@PAGE
Lloh3:
add x8, x8, L_.str@PAGEOFF
stp x0, x9, [sp]
mov x0, x8
bl _printf
ldp x29, x30, [sp, #80] ; 8-byte Folded Reload
add sp, sp, #96 ; =96
ret
.loh AdrpAdd Lloh2, Lloh3
.globl _call_vararg
.p2align 2
_call_vararg: ; @call_vararg
; BB#0:
sub sp, sp, #80 ; =80
stp x29, x30, [sp, #64] ; 8-byte Folded Spill
add x29, sp, #64 ; =64
orr w8, wzr, #0x8
str x8, [sp, #48]
orr w8, wzr, #0x7
orr w9, wzr, #0x6
stp x9, x8, [sp, #32]
mov w8, #5
orr w9, wzr, #0x4
stp x9, x8, [sp, #16]
orr w8, wzr, #0x3
orr w9, wzr, #0x2
stp x9, x8, [sp]
orr w0, wzr, #0x1
bl _vararg_target
ldp x29, x30, [sp, #64] ; 8-byte Folded Reload
add sp, sp, #80 ; =80
ret
.section __TEXT,__cstring,cstring_literals
L_.str: ; @.str
.asciz "%d %d %d %d %d %d %d %d"
.subsections_via_symbols
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