Generate GCC builtins for NVPTX target.

[redstar]

DCompute targets NVPTX, so we should generate the GCC builtins.

[thewilsonator]

Nice. Is there a way we can separate the intrinsics out into related clusters, like dcompute has now? e.g. send "llvm.nvvm.read.*" to index.d "llvm.nvvm.[barrier|membar]*" to sync.d. I think it would be much better w.r.t documentation and intuition of where things should be.

[thewilsonator]

The generated file will have to be marked @compute(CompileFor.deviceOnly), with the corresponding import of ldc.dcompute.

[redstar]

Good hint! This requires an update to the gen_gccbuiltins tool, too.

Currently, the intrinsics are only generated. There is no clustering. Maybe we could just public import the intrinsics in the right module?

[thewilsonator]

That works too.

[redstar]

Updated the gen_gccbuiltins with a small hack.

[kinke]

@JohanEngelen: tests/fuzz_basic.d finally failed again here; output:

3173: WARNING: Failed to find function "__sanitizer_print_stack_trace".
3173: WARNING: Failed to find function "__sanitizer_set_death_callback".
3173: INFO: Seed: 607937059
3173: INFO: Loaded 1 modules (17 guards): [0x46fc60, 0x46fca4), 
3173: INFO: -max_len is not provided; libFuzzer will not generate inputs larger than 4096 bytes
3173: INFO: A corpus is not provided, starting from an empty corpus
3173: #0	READ units: 1
3173: #2	INITED cov: 12 ft: 7 corp: 1/1b exec/s: 0 rss: 23Mb
3173: #7	NEW    cov: 13 ft: 8 corp: 2/35b exec/s: 0 rss: 23Mb L: 34 MS: 5 ChangeByte-InsertByte-ShuffleBytes-ChangeBinInt-InsertRepeatedBytes-
3173: #1276	NEW    cov: 14 ft: 9 corp: 3/4131b exec/s: 0 rss: 23Mb L: 4096 MS: 4 ChangeByte-ShuffleBytes-CMP-CrossOver- DE: "\x08\x00\x00\x00\x00\x00\x00\x00"-
3173: #1048576	pulse  cov: 14 ft: 9 corp: 3/4131b exec/s: 524288 rss: 25Mb
3173: #1625455	NEW    cov: 15 ft: 10 corp: 4/8227b exec/s: 541818 rss: 25Mb L: 4096 MS: 3 ShuffleBytes-PersAutoDict-CMP- DE: "\x08\x00\x00\x00\x00\x00\x00\x00"-"U\x00\x00\x00"-
3173: uncaught exception
3173: core.exception.AssertError@/root/project/tests/sanitizers/fuzz_basic.d(18): Assertion failure
3173: ----------------
3173: ==15612== ERROR: libFuzzer: deadly signal
3173: NOTE: libFuzzer has rudimentary signal handlers.
3173:       Combine libFuzzer with AddressSanitizer or similar for better crash reports.
3173: SUMMARY: libFuzzer: deadly signal
3173: MS: 1 CMP- DE: "Z\x00"-; base unit: b5a0b0b13a0a6f20f09c6309e02984281ee78859
3173: artifact_prefix='./'; Test unit written to ./crash-13c73121ab89c2dde47584c826a38706c65d6b7f

[JohanEngelen]

@thewilsonator Can you add a testcase for this? (// REQUIRES: target_NVPTX)

[thewilsonator]

See https://github.com/ldc-developers/ldc/pull/3993