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| author | Chris Lattner <sabre@nondot.org> | 2011-10-11 23:01:39 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2011-10-11 23:01:39 +0000 |
| commit | 6509f50c69b26b88a77bcae6b9ba84c7e6122b73 (patch) | |
| tree | 8af1e4ede74fafe91f8e5dc5c4b297d1b1693829 /docs | |
| parent | 6618a241f7ba2571a1a55b3733c4441d467baf42 (diff) | |
| download | llvm-6509f50c69b26b88a77bcae6b9ba84c7e6122b73.tar.gz llvm-6509f50c69b26b88a77bcae6b9ba84c7e6122b73.tar.bz2 llvm-6509f50c69b26b88a77bcae6b9ba84c7e6122b73.tar.xz | |
improve some of the documentation around target data layout strings.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@141733 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/LangRef.html | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/docs/LangRef.html b/docs/LangRef.html index 145c19f3e5..8e54f3c433 100644 --- a/docs/LangRef.html +++ b/docs/LangRef.html @@ -1406,6 +1406,22 @@ target datalayout = "<i>layout specification</i>" implemented in terms of 64 <2 x double>, for example.</li> </ol> +<p>The function of the data layout string may not be what you expect. Notably, + this is not a specification from the frontend of what alignment the code + generator should use.</p> + +<p>Instead, if specified, the target data layout is required to match what the + ultimate <em>code generator</em> expects. This string is used by the + mid-level optimizers to + improve code, and this only works if it matches what the ultimate code + generator uses. If you would like to generate IR that does not embed this + target-specific detail into the IR, then you don't have to specify the + string. This will disable some optimizations that require precise layout + information, but this also prevents those optimizations from introducing + target specificity into the IR.</p> + + + </div> <!-- ======================================================================= --> |