gpu/backend.cpp - TerrainGen coverage

gpu/backend.cpp

Line	Branch	Exec	Source
1			#include "terraingen/gpu/backend.h"
2
3			#include "terraingen/gpu/cuda.h"
4			#include "terraingen/gpu/metal.h"
5			#include "terraingen/gpu/vulkan.h"
6
7			#include <atomic>
8			#include <cctype>
9			#include <cstdlib>
10			#include <stdexcept>
11			#include <string>
12
13			namespace terraingen {
14
15			namespace {
16
17			/// The backend `SetDefaultBackend` set, or -1 for none.
18			std::atomic<int> gDefault{-1};
19
20			/// The GPU backends, best first: what `Gpu` and `Auto` choose from.
21			constexpr Backend kGpuBackends[] = {Backend::Metal, Backend::Cuda, Backend::Vulkan};
22
23			/// Whether a backend runs here, on which device, or why not. CUDA and Metal also need their
24			/// kernels in the build (`TERRAINGEN_HAS_CUDA_KERNELS`, `TERRAINGEN_HAS_METAL_KERNELS`).
25		116	BackendStatus ProbeBackend(Backend backend) {
26		116	BackendStatus status{backend, false, {}, {}};
27		68	const auto from = [&](const auto* compute, const std::string& reason) {
28		68	status.available = compute != nullptr;
29	2/4 auto terraingen::(anonymous namespace)::ProbeBackend(terraingen::Backend)::{lambda(auto:1 const, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)#1}::operator()<terraingen::CudaCompute>(terraingen::CudaCompute const, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) const: ✗ Branch 0 not taken. ✓ Branch 1 taken 31 times. auto terraingen::(anonymous namespace)::ProbeBackend(terraingen::Backend)::{lambda(auto:1 const, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)#1}::operator()<terraingen::VulkanCompute>(terraingen::VulkanCompute const, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) const: ✓ Branch 0 taken 37 times. ✗ Branch 1 not taken.	68	if (compute != nullptr) {
30		37	status.device = compute->DeviceName();
31			} else {
32		31	status.reason = reason;
33			}
34		68	};
35	4/5 ✓ Branch 0 taken 17 times. ✓ Branch 1 taken 37 times. ✓ Branch 2 taken 31 times. ✓ Branch 3 taken 31 times. ✗ Branch 4 not taken.	116	switch (backend) {
36		17	case Backend::Cpu:
37		17	status.available = true;
38	1/1 ✓ Branch 1 taken 17 times.	17	status.device = "host";
39		17	break;
40		37	case Backend::Vulkan:
41	3/3 ✓ Branch 1 taken 37 times. ✓ Branch 4 taken 37 times. ✓ Branch 7 taken 37 times.	37	from(VulkanCompute::Get(), VulkanCompute::Reason());
42		37	break;
43		31	case Backend::Cuda:
44			if (TERRAINGEN_HAS_CUDA_KERNELS) {
45	3/3 ✓ Branch 1 taken 31 times. ✓ Branch 4 taken 31 times. ✓ Branch 7 taken 31 times.	31	from(CudaCompute::Get(), CudaCompute::Reason());
46			} else {
47			status.reason =
48			"this build has no CUDA kernels (NVRTC does not run where it was built)";
49			}
50		31	break;
51		31	case Backend::Metal:
52			if (TERRAINGEN_HAS_METAL_KERNELS) {
53			from(MetalCompute::Get(), MetalCompute::Reason());
54			} else {
55	1/1 ✓ Branch 1 taken 31 times.	31	status.reason = MetalCompute::Reason();
56			}
57		31	break;
58		✗	default:
59	0/2 ✗ Branch 2 not taken. ✗ Branch 5 not taken.	✗	status.reason = std::string(BackendName(backend)) + " is not a device backend";
60		✗	break;
61			}
62		232	return status;
63			}
64
65			/// The best GPU backend available; `std::nullopt` when there is none.
66		13	std::optional<Backend> BestGpu() {
67	1/2 ✓ Branch 0 taken 39 times. ✗ Branch 1 not taken.	39	for (const Backend backend : kGpuBackends) {
68	3/3 ✓ Branch 1 taken 39 times. ✓ Branch 4 taken 13 times. ✓ Branch 5 taken 26 times.	39	if (ProbeBackend(backend).available) {
69		13	return backend;
70			}
71			}
72		✗	return std::nullopt;
73			}
74
75			} // namespace
76
77		34	std::optional<Backend> BackendNamed(std::string_view name) {
78	1/1 ✓ Branch 1 taken 34 times.	34	std::string lower(name);
79	2/2 ✓ Branch 4 taken 144 times. ✓ Branch 5 taken 34 times.	178	for (char& c : lower) {
80		144	c = static_cast<char>(std::tolower(static_cast<unsigned char>(c)));
81			}
82		136	for (const Backend backend : {Backend::Auto, Backend::Cpu, Backend::Gpu, Backend::Vulkan,
83	2/2 ✓ Branch 2 taken 129 times. ✓ Branch 3 taken 7 times.	170	Backend::Cuda, Backend::Metal}) {
84	2/2 ✓ Branch 3 taken 27 times. ✓ Branch 4 taken 102 times.	129	if (lower == BackendName(backend)) {
85		27	return backend;
86			}
87			}
88		7	return std::nullopt;
89		34	}
90
91		17467	std::string_view BackendName(Backend backend) {
92	7/7 ✓ Branch 0 taken 36 times. ✓ Branch 1 taken 17329 times. ✓ Branch 2 taken 46 times. ✓ Branch 3 taken 26 times. ✓ Branch 4 taken 16 times. ✓ Branch 5 taken 13 times. ✓ Branch 6 taken 1 time.	17467	switch (backend) {
93		36	case Backend::Auto:
94		36	return "auto";
95		17329	case Backend::Cpu:
96		17329	return "cpu";
97		46	case Backend::Vulkan:
98		46	return "vulkan";
99		26	case Backend::Gpu:
100		26	return "gpu";
101		16	case Backend::Cuda:
102		16	return "cuda";
103		13	case Backend::Metal:
104		13	return "metal";
105			}
106		1	return "unknown";
107			}
108
109		90	std::string DescribeBackend(Backend backend) {
110	4/6 ✓ Branch 0 taken 86 times. ✓ Branch 1 taken 4 times. ✓ Branch 2 taken 86 times. ✗ Branch 3 not taken. ✗ Branch 4 not taken. ✓ Branch 5 taken 86 times.	90	if (backend == Backend::Vulkan \|\| backend == Backend::Cuda \|\| backend == Backend::Metal) {
111	2/3 ✓ Branch 1 taken 4 times. ✓ Branch 3 taken 4 times. ✗ Branch 4 not taken.	4	if (const BackendStatus status = ProbeBackend(backend); status.available) {
112	4/4 ✓ Branch 2 taken 4 times. ✓ Branch 5 taken 4 times. ✓ Branch 8 taken 4 times. ✓ Branch 11 taken 4 times.	4	return std::string(BackendName(backend)) + " (" + status.device + ")";
113	1/2 ✗ Branch 1 not taken. ✓ Branch 2 taken 4 times.	4	}
114			}
115	1/1 ✓ Branch 2 taken 86 times.	86	return std::string(BackendName(backend));
116			}
117
118		17	std::vector<BackendStatus> Backends() {
119			return {ProbeBackend(Backend::Cpu), ProbeBackend(Backend::Vulkan), ProbeBackend(Backend::Cuda),
120	3/5 ✓ Branch 1 taken 17 times. ✓ Branch 3 taken 68 times. ✓ Branch 4 taken 17 times. ✗ Branch 6 not taken. ✗ Branch 7 not taken.	102	ProbeBackend(Backend::Metal)};
121	4/8 ✓ Branch 1 taken 17 times. ✓ Branch 4 taken 17 times. ✓ Branch 7 taken 17 times. ✓ Branch 10 taken 17 times. ✗ Branch 12 not taken. ✗ Branch 13 not taken. ✗ Branch 14 not taken. ✗ Branch 15 not taken.	17	}
122
123		1229	Backend DefaultBackend() {
124	2/2 ✓ Branch 0 taken 587 times. ✓ Branch 1 taken 642 times.	1229	if (const int set = gDefault.load(); set >= 0) {
125		587	return static_cast<Backend>(set);
126			}
127		642	const char* name = std::getenv("TERRAINGEN_BACKEND");
128	4/4 ✓ Branch 0 taken 6 times. ✓ Branch 1 taken 636 times. ✓ Branch 2 taken 1 time. ✓ Branch 3 taken 5 times.	642	if (name == nullptr \|\| *name == '\0') {
129		637	return Backend::Cpu;
130			}
131	3/3 ✓ Branch 2 taken 5 times. ✓ Branch 5 taken 4 times. ✓ Branch 6 taken 1 time.	5	if (const auto backend = BackendNamed(name)) {
132		4	return *backend;
133			}
134	3/3 ✓ Branch 1 taken 1 time. ✓ Branch 4 taken 1 time. ✓ Branch 7 taken 1 time.	2	throw std::invalid_argument("TERRAINGEN_BACKEND is \"" + std::string(name) +
135	1/1 ✓ Branch 2 taken 1 time.	3	"\"; expected auto, cpu, gpu, vulkan, cuda or metal");
136			}
137
138		9	void SetDefaultBackend(Backend backend) {
139			gDefault.store(static_cast<int>(backend));
140		9	}
141
142		1229	Backend ResolveBackend(Backend requested) {
143	4/5 ✓ Branch 0 taken 1211 times. ✓ Branch 1 taken 5 times. ✓ Branch 2 taken 2 times. ✓ Branch 3 taken 11 times. ✗ Branch 4 not taken.	1229	switch (requested) {
144		1211	case Backend::Cpu:
145		1211	return Backend::Cpu;
146		5	case Backend::Vulkan:
147			case Backend::Cuda:
148			case Backend::Metal:
149	3/3 ✓ Branch 1 taken 5 times. ✓ Branch 3 taken 2 times. ✓ Branch 4 taken 3 times.	5	if (const BackendStatus status = ProbeBackend(requested); !status.available) {
150	3/3 ✓ Branch 2 taken 2 times. ✓ Branch 5 taken 2 times. ✓ Branch 8 taken 2 times.	4	throw std::runtime_error("The " + std::string(BackendName(requested)) +
151	2/2 ✓ Branch 2 taken 2 times. ✓ Branch 5 taken 2 times.	6	" backend is unavailable: " + status.reason);
152		5	}
153		3	return requested;
154		2	case Backend::Gpu:
155	2/3 ✓ Branch 1 taken 2 times. ✓ Branch 4 taken 2 times. ✗ Branch 5 not taken.	2	if (const std::optional<Backend> gpu = BestGpu()) {
156		2	return *gpu;
157			}
158			{
159		✗	std::string reasons;
160	0/2 ✗ Branch 0 not taken. ✗ Branch 1 not taken.	✗	for (const Backend backend : kGpuBackends) {
161			reasons +=
162	0/6 ✗ Branch 1 not taken. ✗ Branch 5 not taken. ✗ Branch 8 not taken. ✗ Branch 11 not taken. ✗ Branch 14 not taken. ✗ Branch 17 not taken.	✗	"; " + std::string(BackendName(backend)) + ": " + ProbeBackend(backend).reason;
163			}
164	0/2 ✗ Branch 2 not taken. ✗ Branch 5 not taken.	✗	throw std::runtime_error("No GPU backend is available" + reasons);
165			}
166		11	case Backend::Auto:
167		11	break;
168			}
169	1/1 ✓ Branch 1 taken 11 times.	11	return BestGpu().value_or(Backend::Cpu);
170			}
171
172			} // namespace terraingen
173