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dc73dc09f1
The 'common' section TLS is not implemented. Current C/C++ TLS variables are not placed in common section. DWARF debug info to get the address of TLS variables is not generated yet. clang and driver changes in http://reviews.llvm.org/D10524 Added -femulated-tls flag to select the emulated TLS model, which will be used for old targets like Android that do not support ELF TLS models. Added TargetLowering::LowerToTLSEmulatedModel as a target-independent function to convert a SDNode of TLS variable address to a function call to __emutls_get_address. Added into lib/Target/*/*ISelLowering.cpp to call LowerToTLSEmulatedModel for TLSModel::Emulated. Although all targets supporting ELF TLS models are enhanced, emulated TLS model has been tested only for Android ELF targets. Modified AsmPrinter.cpp to print the emutls_v.* and emutls_t.* variables for emulated TLS variables. Modified DwarfCompileUnit.cpp to skip some DIE for emulated TLS variabls. TODO: Add proper DIE for emulated TLS variables. Added new unit tests with emulated TLS. Differential Revision: http://reviews.llvm.org/D10522 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@243438 91177308-0d34-0410-b5e6-96231b3b80d8
To-do
-----
* Keep the address of the constant pool in a register instead of forming its
address all of the time.
* We can fold small constant offsets into the %hi/%lo references to constant
pool addresses as well.
* When in V9 mode, register allocate %icc[0-3].
* Add support for isel'ing UMUL_LOHI instead of marking it as Expand.
* Emit the 'Branch on Integer Register with Prediction' instructions. It's
not clear how to write a pattern for this though:
float %t1(int %a, int* %p) {
%C = seteq int %a, 0
br bool %C, label %T, label %F
T:
store int 123, int* %p
br label %F
F:
ret float undef
}
codegens to this:
t1:
save -96, %o6, %o6
1) subcc %i0, 0, %l0
1) bne .LBBt1_2 ! F
nop
.LBBt1_1: ! T
or %g0, 123, %l0
st %l0, [%i1]
.LBBt1_2: ! F
restore %g0, %g0, %g0
retl
nop
1) should be replaced with a brz in V9 mode.
* Same as above, but emit conditional move on register zero (p192) in V9
mode. Testcase:
int %t1(int %a, int %b) {
%C = seteq int %a, 0
%D = select bool %C, int %a, int %b
ret int %D
}
* Emit MULX/[SU]DIVX instructions in V9 mode instead of fiddling
with the Y register, if they are faster.
* Codegen bswap(load)/store(bswap) -> load/store ASI
* Implement frame pointer elimination, e.g. eliminate save/restore for
leaf fns.
* Fill delay slots
* Use %g0 directly to materialize 0. No instruction is required.