Add fence instructions.

1 files changed, 28 insertions, 0 deletions

diff --git a/src/fence.rs b/src/fence.rs
new file mode 100644
index 0000000..9268d02
--- /dev/null
+++ b/src/fence.rs
@@ -0,0 +1,28 @@
+//! Intel fence instructions
+
+/// mfence -- Memory Fence
+///
+/// Performs a serializing operation on all load-from-memory and store-to-memory
+/// instructions that were issued prior the MFENCE instruction.
+pub fn mfence() {
+    unsafe { llvm_asm!("mfence" ::: "memory") };
+}
+
+/// sfence -- Store Fence
+///
+/// Orders processor execution relative to all memory stores prior to the SFENCE
+/// instruction. The processor ensures that every store prior to SFENCE is
+/// globally visible before any store after SFENCE becomes globally visible.
+pub fn sfence() {
+    unsafe { llvm_asm!("sfence" ::: "memory") };
+}
+
+/// lfence -- Load Fence
+///
+/// Performs a serializing operation on all load-from-memory instructions that
+/// were issued prior the LFENCE instruction. Specifically, LFENCE does not
+/// execute until all prior instructions have completed locally, and no later
+/// instruction begins execution until LFENCE completes.
+pub fn lfence() {
+    unsafe { llvm_asm!("sfence" ::: "memory") };
+}
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