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Prevent CNTVCT_EL0 reads from being optimised out by the compiler

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Without this the compiler will assume the read always produces the same value, causing issues when the register is used to time function execution
This commit is contained in:
Billy Laws 2022-07-29 19:52:38 +01:00
parent 1df98ba57f
commit 0e1aa765fc
1 changed files with 2 additions and 2 deletions
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4
app/src/main/cpp/skyline/common/utils.h
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@ -27,7 +27,7 @@ namespace skyline::util {
u64 frequency;
asm("MRS %0, CNTFRQ_EL0" : "=r"(frequency));
u64 ticks;
asm("MRS %0, CNTVCT_EL0" : "=r"(ticks));
asm volatile("MRS %0, CNTVCT_EL0" : "=r"(ticks));
return static_cast<i64>(((ticks / frequency) * constant::NsInSecond) + (((ticks % frequency) * constant::NsInSecond + (frequency / 2)) / frequency));
}
@ -37,7 +37,7 @@ namespace skyline::util {
*/
inline u64 GetTimeTicks() {
u64 ticks;
asm("MRS %0, CNTVCT_EL0" : "=r"(ticks));
asm volatile("MRS %0, CNTVCT_EL0" : "=r"(ticks));
return ticks;
}