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| author | Tim Northover <Tim.Northover@arm.com> | 2013-05-04 20:14:09 +0000 |
|---|---|---|
| committer | Tim Northover <Tim.Northover@arm.com> | 2013-05-04 20:14:09 +0000 |
| commit | 4a9b6b798d5ea335f5f29d278db83b830ae4a564 (patch) | |
| tree | 5ee232d04df00a2f62837892d5d400addf0d578a /lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h | |
| parent | 654c2d6b7a9274fc281c30c0e91419aadb6dc78a (diff) | |
| download | llvm-4a9b6b798d5ea335f5f29d278db83b830ae4a564.tar.gz llvm-4a9b6b798d5ea335f5f29d278db83b830ae4a564.tar.bz2 llvm-4a9b6b798d5ea335f5f29d278db83b830ae4a564.tar.xz | |
AArch64: add stubs to support long function calls on MCJIT
As with global accesses, external functions could exist anywhere in
memory. Therefore the stub must create a complete 64-bit address. This
patch implements the fragment as (roughly):
movz x16, #:abs_g3:somefunc
movk x16, #:abs_g2_nc:somefunc
movk x16, #:abs_g1_nc:somefunc
movk x16, #:abs_g0_nc:somefunc
br x16
In principle we could save 4 bytes by using a literal-load instead,
but it is unclear that would be more efficient and can only be tested
when real hardware is readily available.
This allows (for example) the MCJIT test 2003-05-07-ArgumentTest to
pass on AArch64.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181133 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h')
| -rw-r--r-- | lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h index 9d767a067c..b09e71ed4b 100644 --- a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h +++ b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h @@ -166,6 +166,8 @@ protected: Triple::ArchType Arch; inline unsigned getMaxStubSize() { + if (Arch == Triple::aarch64) + return 20; // movz; movk; movk; movk; br if (Arch == Triple::arm || Arch == Triple::thumb) return 8; // 32-bit instruction and 32-bit address else if (Arch == Triple::mipsel || Arch == Triple::mips) |