compiler_rt: atomics: Add Leon CAS instruction check for SPARC atomics

This commit is contained in:
Koakuma 2022-04-15 19:40:36 +07:00
parent 6aa89115f9
commit 5b283fba77

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@ -1,6 +1,7 @@
const std = @import("std");
const builtin = @import("builtin");
const arch = builtin.cpu.arch;
const cpu = builtin.cpu;
const arch = cpu.arch;
const linkage: std.builtin.GlobalLinkage = if (builtin.is_test) .Internal else .Weak;
@ -27,9 +28,7 @@ const largest_atomic_size = switch (arch) {
// On SPARC systems that lacks CAS and/or swap instructions, the only
// available atomic operation is a test-and-set (`ldstub`), so we force
// every atomic memory access to go through the lock.
// XXX: Check the presence of CAS/swap instructions and set this parameter
// accordingly.
.sparc, .sparcel, .sparcv9 => 0,
.sparc, .sparcel => if (cpu.features.featureSetHas(.hasleoncasa)) @sizeOf(usize) else 0,
// XXX: On x86/x86_64 we could check the presence of cmpxchg8b/cmpxchg16b
// and set this parameter accordingly.