Commit 9d23e711ef
Changed files (1)
lib
std
lib/std/atomic.zig
@@ -378,21 +378,33 @@ pub inline fn spinLoopHint() void {
// No-op instruction that can hint to save (or share with a hardware-thread)
// pipelining/power resources
// https://software.intel.com/content/www/us/en/develop/articles/benefitting-power-and-performance-sleep-loops.html
- .x86, .x86_64 => asm volatile ("pause" ::: "memory"),
+ .x86,
+ .x86_64,
+ => asm volatile ("pause" ::: "memory"),
// No-op instruction that serves as a hardware-thread resource yield hint.
// https://stackoverflow.com/a/7588941
- .powerpc64, .powerpc64le => asm volatile ("or 27, 27, 27" ::: "memory"),
+ .powerpc,
+ .powerpcle,
+ .powerpc64,
+ .powerpc64le,
+ => asm volatile ("or 27, 27, 27" ::: "memory"),
// `isb` appears more reliable for releasing execution resources than `yield`
// on common aarch64 CPUs.
// https://bugs.java.com/bugdatabase/view_bug.do?bug_id=8258604
// https://bugs.mysql.com/bug.php?id=100664
- .aarch64, .aarch64_be => asm volatile ("isb" ::: "memory"),
+ .aarch64,
+ .aarch64_be,
+ => asm volatile ("isb" ::: "memory"),
// `yield` was introduced in v6k but is also available on v6m.
// https://www.keil.com/support/man/docs/armasm/armasm_dom1361289926796.htm
- .arm, .armeb, .thumb, .thumbeb => {
+ .arm,
+ .armeb,
+ .thumb,
+ .thumbeb,
+ => {
const can_yield = comptime std.Target.arm.featureSetHasAny(builtin.target.cpu.features, .{
.has_v6k, .has_v6m,
});
@@ -402,6 +414,22 @@ pub inline fn spinLoopHint() void {
asm volatile ("" ::: "memory");
}
},
+
+ // The 8-bit immediate specifies the amount of cycles to pause for. We can't really be too
+ // opinionated here.
+ .hexagon,
+ => asm volatile ("pause(#1)" ::: "memory"),
+
+ .riscv32,
+ .riscv64,
+ => {
+ if (comptime std.Target.riscv.featureSetHas(builtin.target.cpu.features, .zihintpause)) {
+ asm volatile ("pause" ::: "memory");
+ } else {
+ asm volatile ("" ::: "memory");
+ }
+ },
+
// Memory barrier to prevent the compiler from optimizing away the spin-loop
// even if no hint_instruction was provided.
else => asm volatile ("" ::: "memory"),