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discovered macro names cannot clash with instruction names on gcc linux

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Perry Kivolowitz 2023-01-17 12:02:33 -06:00
parent 2370bf7163
commit d09b35ed28
2 changed files with 140 additions and 25 deletions
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110
more/apple_silicon/apple-linux-convergence.S Normal file
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// Macros to permit the "same" assembly language to build on ARM64
// Linux systems as well as Apple Silicon systems.
//
// Perry Kivolowitz
// A Gentle Introduction to Assembly Language
#if defined(__APPLE__)
// Apple makes a distinction between loading something close by
// versus something global. Note the use of GOTPAGE rather then
// PAGE.
//
// Note: this macro dereferences the label getting what is at
// the label's address.
.macro GLD_PTR xreg, label // Dereference a global *
adrp \xreg, _\label@GOTPAGE
ldr \xreg, [\xreg, _\label@GOTPAGEOFF]
.endm
.macro GLD_ADDR xreg, label // Get a global address
adrp \xreg, _\label@GOTPAGE
add \xreg, \xreg, _\label@GOTPAGEOFF
.endm
// This macro loads the address of a nearby label.
.macro LLD_ADDR xreg, label // Load a local address
adrp \xreg, \label@PAGE
add \xreg, \xreg, \label@PAGEOFF
.endm
.macro GLABEL label
.global _\label
.endm
.macro MAIN
_main:
.endm
.macro CRT label
bl _\label
.endm
#else // LINUX
.macro GLABEL label
.global \label
.endm
.macro MAIN
main:
.endm
.macro CRT label
bl \label
.endm
// This macro treats label as a pointer and dereferences it.
// That is, it puts into the xreg what is found at the address
// of the label.
.macro GLD_PTR xreg, label // Dereference a global *
ldr \xreg, =\label
ldr \xreg, [\xreg]
.endm
// This macro loads the address of a nearby label.
.macro LLD_ADDR xreg, label
ldr \xreg, =\label
.endm
.macro LD_ADDR xreg, label
.endm
#endif
.macro START_PROC // after starting label
.cfi_startproc
.endm
.macro END_PROC // after the return
.cfi_endproc
.endm
.macro PUSH_P a, b
stp \a, \b, [sp, -16]!
.endm
.macro PUSH_R a
str \a, [sp, -16]!
.endm
.macro POP_P a, b
ldp \a, \b, [sp], 16
.endm
.macro POP_R a
ldr \a, [sp], 16
.endm
.macro MIN src_a, src_b, dest
csel \dest, \src_a, \src_b, GT
.endm
.macro MAX src_a, src_b, dest
csel \dest, \src_a, \src_b, LT
.endm

55
more/apple_silicon/stub.S
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#include "macros.S"
#include "apple-linux-convergence.S"
/* This is a short demonstration of the macro suite in development
to enable writing AARCH64 assembly language once and be able to
build on both Apple Silicon and Linux machines.
Documentation can be found at:
https://github.com/pkivolowitz/asm_book
Perry Kivolowitz
*/
.align 2
.text
GLABEL main
// adrp loads an address using a page number containing the variable
MAIN
START_PROC
stp x21, x30, [sp, -16]!
str x29, [sp, -16]!
mov x29, sp
PUSH_P x21, x30
PUSH_R x29
mov x29, sp
mov x0, 8 // allocating a long
CRT malloc // call malloc()
mov x1, 0xFF // load payload
str x1, [x0] // store payload
LD_ADDR x1, ptr
str x0, [x1]
mov x0, 8 // allocating a long's worth of RAM
CRT malloc // call malloc()
mov x1, 0xFF // load payload
str x1, [x0] // store payload
LLD_ADDR x1, ptr // local load address
str x0, [x1]
LD_ADDR x0, fmt // loads the address of fmt
LD_ADDR x1, ptr // loads **ptr
ldr x1, [x1] // dereferences **ptr to make *ptr
ldr x2, [x1] // dereferences *ptr to get value
LLD_ADDR x0, fmt // loads the address of fmt
LLD_ADDR x1, ptr // loads **ptr
ldr x1, [x1] // dereferences **ptr to make *ptr
ldr x2, [x1] // dereferences *ptr to get value
#if defined(__APPLE__)
stp x1, x2, [sp, -16]!
CRT printf
add sp, sp, 16
PUSH_P x1, x2
CRT printf
add sp, sp, 16
#else
CRT printf
CRT printf
#endif
mov x0, xzr
ldr x29, [sp], 16
ldp x21, x30, [sp], 16
POP_R x29
POP_P x21, x30
mov x0, xzr
ret
END_PROC