Tier System: hexagon-linux

[alexrp]

• Standard library support
• libc is available even when cross-compiling
• Stack traces work
• All behavior tests pass
• All standard library tests pass
• No disabled tests
• Enabled in CI (QEMU)

Open issues:

• Consider integrating Qualcomm's musl port for Hexagon #21588
• Re-enable native f16 lowering for Hexagon #22013

[alexrp]

Just noting that further progress on this port is basically blocked until LLVM 20 due to llvm/llvm-project#116798; we can't link anything larger than trivial freestanding programs due to it, including all module tests.

[androm3da]

Just noting that further progress on this port is basically blocked until LLVM 20 due to llvm/llvm-project#116798; we can't link anything larger than trivial freestanding programs due to it, including all module tests.

This has now been backported to 19.1.5 - sorry for the inconvenience. Let me know if you come across any other issues.

[alexrp]

This has now been backported to 19.1.5 - sorry for the inconvenience. Let me know if you come across any other issues.

Nice; I wasn't confident the backport would be accepted. Thanks!

[alexrp]

test-c-import, test-compiler-rt, and test-universal-libc now pass.

test-behavior fails with:

test-behavior
└─ run test behavior-hexagon-linux.4.19...6.11.5-none.2.28-hexagonv60-Debug
   └─ zig test Debug hexagon-linux-none failure
error: zig: /home/alexrp/Source/llvm-project/llvm/include/llvm/CodeGen/ValueTypes.h:307: llvm::MVT llvm::EVT::getSimpleVT() const: Assertion `isSimple() && "Expected a SimpleValueType!"' failed.

error: the following command terminated unexpectedly:
/home/alexrp/Source/ziglang/zig/zig-out/bin/zig test -ODebug -target hexagon-linux-none -mcpu baseline -Mroot=/home/alexrp/Source/ziglang/zig/test/behavior.zig --cache-dir /home/alexrp/Source/ziglang/zig/.zig-cache --global-cache-dir /home/alexrp/.cache/zig --name test -L /opt/llvm-19/lib -I /opt/llvm-19/include --zig-lib-dir /home/alexrp/Source/ziglang/zig/lib --listen=-

test-std fails with:

test-std
└─ run test std-hexagon-linux.4.19...6.11.5-none.2.28-hexagonv60-Debug
   └─ zig test Debug hexagon-linux-none failure
error: Call operand #1 has unhandled type v4i1
UNREACHABLE executed at /home/alexrp/Source/llvm-project/llvm/lib/CodeGen/CallingConvLower.cpp:137!

error: the following command terminated unexpectedly:
/home/alexrp/Source/ziglang/zig/zig-out/bin/zig test -ODebug -target hexagon-linux-none -mcpu baseline -Mroot=/home/alexrp/Source/ziglang/zig/lib/std/std.zig --cache-dir /home/alexrp/Source/ziglang/zig/.zig-cache --global-cache-dir /home/alexrp/.cache/zig --name test -L /opt/llvm-19/lib -I /opt/llvm-19/include --zig-lib-dir /home/alexrp/Source/ziglang/zig/lib --listen=-

We're probably exercising a lot of code paths in the Hexagon backend that Clang doesn't. 🙂

[alexrp]

• [Hexagon] Cannot handle call operand v8i1 llvm/llvm-project#59009
• [llvm][Hexagon] Expected a SimpleValueType crash with vectors of large integers llvm/llvm-project#118881

[alexrp]

Current upstream issues that affect Zig's behavior tests:

• [llvm][Hexagon] unable to allocate function argument crash in llvm::HexagonTargetLowering::LowerFormalArguments() llvm/llvm-project#118879
• [Hexagon] Cannot select: t89: v4i1 = HexagonISD::PFALSE llvm/llvm-project#134659
• [lld] Add thunks for hexagon llvm/llvm-project#111217

[androm3da]

Current upstream issues that affect Zig's behavior tests:

...

• [lld] Add thunks for hexagon llvm/llvm-project#111217

Another effective workaround for this limitation in lld is to use eld (https://github.com/qualcomm/eld). Is that satisfactory or does zig assume/require lld? At some time in the not-too-distant future (21.0?), clang should pick eld as the default linker for hexagon (see llvm/llvm-project#135200).

[alexrp]

The only external linker we can depend on currently is LLD and that's because we link it into the zig executable. But the plan is to eliminate that dependency over the coming release cycles in favor of our self-hosted linker (#8726).

[androm3da]

The only external linker we can depend on currently is LLD and that's because we link it into the zig executable. But the plan is to eliminate that dependency over the coming release cycles in favor of our self-hosted linker (#8726).

Okay, then - we'll get the trampolines sorted in lld.