diff options
| author | hev <wangrui@loongson.cn> | 2023-12-05 10:42:53 +0900 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2023-12-05 09:42:53 +0800 |
| commit | a8874cf50bb676facb4429234dff7774e579faef (patch) | |
| tree | 6be8c35a41ca83803dcbf9efc37457ab014c9945 /llvm/docs/LangRef.rst | |
| parent | 192439db6e3fcccf98c850bda1b970a11c590bbb (diff) | |
| download | llvm-a8874cf50bb676facb4429234dff7774e579faef.zip llvm-a8874cf50bb676facb4429234dff7774e579faef.tar.gz llvm-a8874cf50bb676facb4429234dff7774e579faef.tar.bz2 | |
[llvm][IR] Add per-global code model attribute (#72077)
This adds a per-global code model attribute, which can override the
target's code model to access global variables.
Suggested-by: Arthur Eubanks <aeubanks@google.com>
Link: https://discourse.llvm.org/t/how-to-best-implement-code-model-overriding-for-certain-values/71816
Link: https://discourse.llvm.org/t/rfc-add-per-global-code-model-attribute/74944
Diffstat (limited to 'llvm/docs/LangRef.rst')
| -rw-r--r-- | llvm/docs/LangRef.rst | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/llvm/docs/LangRef.rst b/llvm/docs/LangRef.rst index 4bd19a3..cf9b33a 100644 --- a/llvm/docs/LangRef.rst +++ b/llvm/docs/LangRef.rst @@ -705,6 +705,13 @@ information. Attaching section information to an external declaration is an assertion that its definition is located in the specified section. If the definition is located in a different section, the behavior is undefined. +LLVM allows an explicit code model to be specified for globals. If the +target supports it, it will emit globals in the code model specified, +overriding the code model used to compile the translation unit. +The allowed values are "tiny", "small", "kernel", "medium", "large". +This may be extended in the future to specify global data layout that +doesn't cleanly fit into a specific code model. + By default, global initializers are optimized by assuming that global variables defined within the module are not modified from their initial values before the start of the global initializer. This is @@ -761,6 +768,7 @@ Syntax:: <global | constant> <Type> [<InitializerConstant>] [, section "name"] [, partition "name"] [, comdat [($name)]] [, align <Alignment>] + [, code_model "model"] [, no_sanitize_address] [, no_sanitize_hwaddress] [, sanitize_address_dyninit] [, sanitize_memtag] (, !name !N)* @@ -778,6 +786,13 @@ The following example just declares a global variable @G = external global i32 +The following example defines a global variable with the +``large`` code model: + +.. code-block:: llvm + + @G = internal global i32 0, code_model "large" + The following example defines a thread-local global with the ``initialexec`` TLS model: |