CUDA-12 no longer supports 32-bit compilation.
Tests agnostic to 32/64 compilation mode are switched to use nvptx64.
Tests that do care about it have 32-bit ptxas compilation disabled with cuda-12+.
Differential Revision: https://reviews.llvm.org/D152199
Minimum alignment of 4 for byval arguments was forced to workaround
a bug in old versions of ptxas. Details: https://reviews.llvm.org/D22428.
Recent ptxas versions (> 9.0) do not seem to have this bug, so alignment
requirement was relaxed. To force again minimum alignment of 4, use
'-force-min-byval-param-align' option.
As a result, we have identical alignment calculation of byval
parameters for:
- LowerCall() - getting alignment of an argument (.param)
- emitFunctionParamList() - getting alignment of a
parameter (.param) in a function declaration
- getPrototype() - getting alignment of a parameter (.param) in a
function prototypes that is used for indirect calls
This change is required to avoid ptxas error: 'Alignment of argument
does not match formal parameter'. This error happens even in cases
where it logically shouldn't.
For instance:
.param .align 4 .b8 param0[4];
...
callprototype ()_ (.param .align 2 .b8 _[4]);
...
Here we allocate 'param0' with alignment of 4 and it should be fine to
pass it to a function that requires minimum alignment of 2.
At least ptxas v12.0 rejects this code.
Differential Revision: https://reviews.llvm.org/D140581
ptxas is a proprietary compiler from Nvidia that can compile PTX to
machine code (SASS). It has a lot of diagnostics to catch errors
in PTX, which can be used to verify PTX output from llc.
Set -DPXTAS_EXECUTABLE=/path/to/ptxas CMake option to enable it.
If this option is not set, then ptxas is substituted to true which
effectively disables all ptxas RUN lines.
LLVM_PTXAS_EXECUTABLE environment variable takes precedence over
the CMake option, and allows to override ptxas executable that is used for LIT
without complete re-configuration.
Differential Revision: https://reviews.llvm.org/D121727
Taking address of a byval variable in PTX is legal, but currently runs
into miscompilation by ptxas on sm_50+ (NVIDIA issue 1789042).
Work around the issue by enforcing minimum alignment on byval arguments
of device functions.
The change is a no-op on SASS level for sm_3x where ptxas already aligns
local copy by at least 4.
Differential Revision: https://reviews.llvm.org/D22428
llvm-svn: 275893
