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AK+Everywhere: Replace __builtin bit functions

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In order to reduce our reliance on __builtin_{ffs, clz, ctz, popcount},
this commit removes all calls to these functions and replaces them with
the equivalent functions in AK/BuiltinWrappers.h.
This commit is contained in:
Nick Johnson 2021-12-19 15:46:55 -06:00 • committed by Andreas Kling
parent 26bb3e1acf
commit 08e4a1a4dc
20 changed files with 108 additions and 115 deletions
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9
Kernel/Arch/x86/common/Processor.cpp
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@ -4,6 +4,7 @@
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/BuiltinWrappers.h>
#include <AK/Format.h>
#include <AK/StdLibExtras.h>
#include <AK/String.h>
@ -771,13 +772,13 @@ u32 Processor::smp_wake_n_idle_processors(u32 wake_count)
while (did_wake_count < wake_count) {
// Try to get a set of idle CPUs and flip them to busy
u32 idle_mask = s_idle_cpu_mask.load(AK::MemoryOrder::memory_order_relaxed) & ~(1u << current_id);
u32 idle_count = __builtin_popcountl(idle_mask);
u32 idle_count = popcount(idle_mask);
if (idle_count == 0)
break; // No (more) idle processor available
u32 found_mask = 0;
for (u32 i = 0; i < idle_count; i++) {
u32 cpu = __builtin_ffsl(idle_mask) - 1;
u32 cpu = bit_scan_forward(idle_mask) - 1;
idle_mask &= ~(1u << cpu);
found_mask |= 1u << cpu;
}
@ -785,9 +786,9 @@ u32 Processor::smp_wake_n_idle_processors(u32 wake_count)
idle_mask = s_idle_cpu_mask.fetch_and(~found_mask, AK::MemoryOrder::memory_order_acq_rel) & found_mask;
if (idle_mask == 0)
continue; // All of them were flipped to busy, try again
idle_count = __builtin_popcountl(idle_mask);
idle_count = popcount(idle_mask);
for (u32 i = 0; i < idle_count; i++) {
u32 cpu = __builtin_ffsl(idle_mask) - 1;
u32 cpu = bit_scan_forward(idle_mask) - 1;
idle_mask &= ~(1u << cpu);
// Send an IPI to that CPU to wake it up. There is a possibility