[SYCL][Driver] Respect the -target cross-compilation flag. #2417
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clang/test/Driver/sycl-device.cpp
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| /// Check that -aux-triple is set correctly | ||
| // RUN: %clang -### -fsycl -target aarch64-linux-gnu %s 2>&1 \ | ||
| // RUN: | FileCheck -check-prefix=CHECK-SYCL-AUX-TRIPLE %s | ||
| // CHECK-SYCL-AUX-TRIPLE-NOT: clang{{.*}} "x86_64-unknown-linux-gnu" |
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What is the value of CHECK-SYCL-AUX-TRIPLE-NOT checks?
I think this test doesn't make sense on aarch64, right?
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yeah this test is trivially true on when running non x86 systems.
there doesn't seem to be a way to query the the triple of the device running the test.
after taking a look at what other cross-compilation test do they don't seem to have check like this so i removed the check.
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| auto AuxT = llvm::Triple(llvm::sys::getProcessTriple()); | ||
| llvm::Triple AuxT = C.getDefaultToolChain().getTriple(); | ||
| if (Args.hasFlag(options::OPT_fsycl_device_only, OptSpecifier(), false)) | ||
| AuxT = llvm::Triple(llvm::sys::getProcessTriple()); |
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Why not also do this for -fsycl-device-only?
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When compiling in -fsycl-device-only the default toolchain of the compilation is the device target not the host target. i don't think the host target is actually known when building in -fsycl-device-only.
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@mdtoguchi interesting question... But I have the feeling that compiling for the device is already a kind of cross-compilation per se.
Our use case is when we compile SYCL code on x86 for Xilinx ACAP AIE devices where the host is ARM64 and the devices other specific VLIW DSP.
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When compiling in -fsycl-device-only the default toolchain of the compilation is the device target not the host target. i don't think the host target is actually known when building in -fsycl-device-only.
It's known (via -aux-triple) and it's required to fix the sizes of data types like int for both: host and device (and for some other reasons). Otherwise host/device ABI might be incompatible.
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-aux-triple is a cc1 only flag so the driver can't really know.
i changed it to be cc1 or dirver.
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I suppose this might be related to #1814. I'm not sure if we can address Mike's comment easily.
@mdtoguchi, should we resolve it in scope of #1814 or there is an easy fix here?
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Use of -fsycl-device-only should behave in a simlar fashion to -fsycl in regards to the device compilation step. The disconnects need to be addressed as stated in #1814 . The behavior being seen with the error emitted when using -fsycl-targets with -fsycl -fsycl-device-only is not intentional.
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@mdtoguchi, let me check that I understand current status correctly.
Am I right that handling -fsycl-device-only+-target together is blocked by #1814 and we agree to resolve it separately?
Anyway, I think we all agree that we should not add -aux-triple driver option. Right?
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@mdtoguchi, let me check that I understand current status correctly.
Am I right that handling-fsycl-device-only+-targettogether is blocked by #1814 and we agree to resolve it separately?
I brought back the patch before a driver -aux-triple to resolve it separately.
Anyway, I think we all agree that we should not add
-aux-tripledriver option. Right?
I agree and I think the behavior you described is a better solution than a driver -aux-triple.
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Agree. #1814 should be resolved separately and we do not need -aux-triple driver option.
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@Ralender, could you resolve the conflicts with the tip of the sycl branch, please? |
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fixed |
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@Ralender, @mdtoguchi, thanks! |
Currently when compiling with for sycl with a -target flag, clang will invoke the device compilation with an auxiliary triple of the machine performing the compilation instead of the host target completely ignoring the -target flag.
This patch fixes this.