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| author | Ben Gamari <bgamari.foss@gmail.com> | 2014-11-21 21:05:25 +0100 |
|---|---|---|
| committer | Herbert Valerio Riedel <hvr@gnu.org> | 2014-11-21 22:32:16 +0100 |
| commit | e16a342d70b92fc8480793d3ec911853f0c31e44 (patch) | |
| tree | a566c89ae63c6953a68ecf0292c27c9f781b0e59 /compiler/llvmGen/LlvmCodeGen.hs | |
| parent | 2a523ebf091478aea39deef28073320bed628434 (diff) | |
| download | haskell-e16a342d70b92fc8480793d3ec911853f0c31e44.tar.gz | |
llvmGen: Compatibility with LLVM 3.5 (re #9142)
Due to changes in LLVM 3.5 aliases now may only refer to definitions.
Previously to handle symbols defined outside of the current commpilation
unit GHC would emit both an `external` declaration, as well as an alias
pointing to it, e.g.,
@stg_BCO_info = external global i8
@stg_BCO_info$alias = alias private i8* @stg_BCO_info
Where references to `stg_BCO_info` will use the alias
`stg_BCO_info$alias`. This is not permitted under the new alias
behavior, resulting in errors resembling,
Alias must point to a definition
i8* @"stg_BCO_info$alias"
To fix this, we invert the naming relationship between aliases and
definitions. That is, now the symbol definition takes the name
`@stg_BCO_info$def` and references use the actual name, `@stg_BCO_info`.
This means the external symbols can be handled by simply emitting an
`external` declaration,
@stg_BCO_info = external global i8
Whereas in the case of a forward declaration we emit,
@stg_BCO_info = alias private i8* @stg_BCO_info$def
Reviewed By: austin
Differential Revision: https://phabricator.haskell.org/D155
Diffstat (limited to 'compiler/llvmGen/LlvmCodeGen.hs')
| -rw-r--r-- | compiler/llvmGen/LlvmCodeGen.hs | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/compiler/llvmGen/LlvmCodeGen.hs b/compiler/llvmGen/LlvmCodeGen.hs index dd16e52868..6120a72d3a 100644 --- a/compiler/llvmGen/LlvmCodeGen.hs +++ b/compiler/llvmGen/LlvmCodeGen.hs @@ -81,7 +81,7 @@ llvmCodeGen' cmm_stream _ <- Stream.collect llvmStream -- Declare aliases for forward references - renderLlvm . pprLlvmData =<< generateAliases + renderLlvm . pprLlvmData =<< generateExternDecls -- Postamble cmmUsedLlvmGens @@ -120,8 +120,9 @@ cmmDataLlvmGens statics = funInsert l ty regGlobal _ = return () mapM_ regGlobal (concat gss) + gss' <- mapM aliasify $ concat gss - renderLlvm $ pprLlvmData (concat gss, concat tss) + renderLlvm $ pprLlvmData (concat gss', concat tss) -- | Complete LLVM code generation phase for a single top-level chunk of Cmm. cmmLlvmGen ::RawCmmDecl -> LlvmM () |