1 files changed, 22 insertions, 0 deletions

diff --git a/llvm/docs/LangRef.rst b/llvm/docs/LangRef.rst
index 167a33e7c3d..2aba2077653 100644
--- a/llvm/docs/LangRef.rst
+++ b/llvm/docs/LangRef.rst
@@ -1636,6 +1636,28 @@ example:
     This attribute indicates that HWAddressSanitizer checks
     (dynamic address safety analysis based on tagged pointers) are enabled for
     this function.
+``speculative_load_hardening``
+    This attribute indicates that
+    `Speculative Load Hardening <https://llvm.org/docs/SpeculativeLoadHardening.html>`_
+    should be enabled for the function body. This is a best-effort attempt to
+    mitigate all known speculative execution information leak vulnerabilities
+    that are based on the fundamental principles of modern processors'
+    speculative execution. These vulnerabilities are classified as "Spectre
+    variant #1" vulnerabilities typically. Notably, this does not attempt to
+    mitigate any vulnerabilities where the speculative execution and/or
+    prediction devices of specific processors can be *completely* undermined
+    (such as "Branch Target Injection", a.k.a, "Spectre variant #2"). Instead,
+    this is a target-independent request to harden against the completely
+    generic risk posed by speculative execution to incorrectly load secret data,
+    making it available to some micro-architectural side-channel for information
+    leak. For a processor without any speculative execution or predictors, this
+    is expected to be a no-op.
+
+    When inlining, the attribute is sticky. Inlining a function that carries
+    this attribute will cause the caller to gain the attribute. This is intended
+    to provide a maximally conservative model where the code in a function
+    annotated with this attribute will always (even after inlining) end up
+    hardened.
 ``speculatable``
     This function attribute indicates that the function does not have any
     effects besides calculating its result and does not have undefined behavior.