llvm-project/clang/test/OpenMP/amdgpu_exceptions.cpp
Anton Rydahl 0cfc2dba93 [OpenMP] Allow exceptions in target regions when offloading to GPUs
The motivation for this patch is that many code bases use exception handling. As GPUs are not expected to support exception handling in the near future, we can experiment with compiling the code for GPU targets anyway. This will
allow us to run the code, as long as no exception is thrown.

The overall idea is very simple:
- If a throw expression is compiled to AMDGCN or NVPTX, it is replaced with a trap during code generation.
- If a try/catch statement is compiled to AMDGCN or AMDHSA, we ganerate code for the try statement as if it were a basic block.

With this patch, the compilation of the following example
```{C++}
int gaussian_sum(int a,int b){
	if ((a + b) % 2 == 0) {throw -1;};
	return (a+b) * ((a+b)/2);
}

int main(void) {
	int gauss = 0;
	#pragma omp target map(from:gauss)
	{
		try {
			gauss = gaussian_sum(1,100);
		}
		catch (int e){
			gauss = e;
		}
	}
	std::cout << "GaussianSum(1,100)="<<gauss<<std::endl;
        #pragma omp target map(from:gauss)
        {
                try {
                     	gauss = gaussian_sum(1,101);
                }
                catch (int e){
                        gauss = e;
                }
        }
	std::cout << "GaussianSum(1,101)="<<gauss<<std::endl;
	return (gauss > 1) ? 0 : 1;
}
```
with offloading to `gfx906` results in
```{bash}
./bin/target_try_minimal_fail
GaussianSum(1,100)=5050
AMDGPU fatal error 1: Received error in queue 0x155555506000: HSA_STATUS_ERROR_EXCEPTION: An HSAIL operation resulted in a hardware exception.
zsh: abort (core dumped)
```

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D153924
2023-08-28 22:36:13 -07:00

47 lines
2.5 KiB
C++

/**
* The first four lines test that a warning is produced when enabling
* -Wopenmp-target-exception no matter what combination of -fexceptions and
* -fcxx-exceptions are set, as we want OpenMP to always allow exceptions in the
* target region but emit a warning instead.
*/
// RUN: %clang_cc1 -fopenmp -triple amdgcn-amd-amdhsa -fopenmp-is-target-device -fcxx-exceptions -fexceptions %s -emit-llvm -S -verify=with -Wopenmp-target-exception -analyze
// RUN: %clang_cc1 -fopenmp -triple amdgcn-amd-amdhsa -fopenmp-is-target-device -fcxx-exceptions -fexceptions %s -emit-llvm -S -verify=with -Wopenmp-target-exception -analyze
// RUN: %clang_cc1 -fopenmp -triple amdgcn-amd-amdhsa -fopenmp-is-target-device -fexceptions %s -emit-llvm -S -verify=with -Wopenmp-target-exception -analyze
// RUN: %clang_cc1 -fopenmp -triple amdgcn-amd-amdhsa -fopenmp-is-target-device %s -emit-llvm -S -verify=with -Wopenmp-target-exception -analyze
/**
* The following four lines test that no warning is emitted when providing
* -Wno-openmp-target-exception no matter the combination of -fexceptions and
* -fcxx-exceptions.
*/
// RUN: %clang_cc1 -fopenmp -triple amdgcn-amd-amdhsa -fopenmp-is-target-device -fcxx-exceptions -fexceptions %s -emit-llvm -S -verify=without -Wno-openmp-target-exception -analyze
// RUN: %clang_cc1 -fopenmp -triple amdgcn-amd-amdhsa -fopenmp-is-target-device -fcxx-exceptions %s -emit-llvm -S -verify=without -Wno-openmp-target-exception -analyze
// RUN: %clang_cc1 -fopenmp -triple amdgcn-amd-amdhsa -fopenmp-is-target-device -fexceptions %s -emit-llvm -S -verify=without -Wno-openmp-target-exception -analyze
// RUN: %clang_cc1 -fopenmp -triple amdgcn-amd-amdhsa -fopenmp-is-target-device %s -emit-llvm -S -verify=without -Wno-openmp-target-exception -analyze
/**
* Finally we should test that we only ignore exceptions in the OpenMP
* offloading tool-chain
*/
// RUN: %clang_cc1 -triple amdgcn-amd-amdhsa %s -emit-llvm -S -verify=noexceptions -o -
// noexceptions-error@37 {{cannot use 'try' with exceptions disabled}}
// noexceptions-error@38 {{cannot use 'throw' with exceptions disabled}}
#pragma omp declare target
int foo(void) {
int error = -1;
try { // with-warning {{target 'amdgcn-amd-amdhsa' does not support exception handling; 'catch' block is ignored}}
throw 404; // with-warning {{target 'amdgcn-amd-amdhsa' does not support exception handling; 'throw' is assumed to be never reached}}
}
catch (int e){
error = e;
}
return error;
}
#pragma omp end declare target
// without-no-diagnostics