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nrf/gccollect: Use the SP register instead of MSP. 

Using the current stack pointer directly saves 8 bytes of code.
We need the *current* register anyway for GC (which is always MSP).
This commit is contained in:
Ayke van Laethem 2018-03-26 15:01:35 +02:00 committed by Damien George
parent 013c23712c
commit 65f8d9a643
1 changed files with 7 additions and 7 deletions
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14
ports/nrf/gccollect.c
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@ -31,19 +31,19 @@
#include "py/gc.h"
#include "gccollect.h"
static inline uint32_t get_msp(void)
{
register uint32_t result;
__asm volatile ("MRS %0, msp\n" : "=r" (result) );
return(result);
static inline uintptr_t get_sp(void) {
uintptr_t result;
__asm__ ("mov %0, sp\n" : "=r" (result) );
return result;
}
void gc_collect(void) {
// start the GC
gc_collect_start();
mp_uint_t sp = get_msp(); // Get stack pointer
// Get stack pointer
uintptr_t sp = get_sp();
// trace the stack, including the registers (since they live on the stack in this function)
gc_collect_root((void**)sp, ((uint32_t)&_ram_end - sp) / sizeof(uint32_t));