Update to LLVM 11.0.1

[cuviper]

This updates to a new LLVM branch, rebased on the upstream llvmorg-11.0.1. All our patches applied cleanly except the fortanix unwind changes, which just needed a small adjustment in cmake files.

r? @nikic
Fixes #73722

[rust-highfive]

⚠️ Warning ⚠️

• These commits modify submodules.

[nikic]

Thanks!

@bors r+

[bors]

📌 Commit c1d9423 has been approved by nikic

[bors]

⌛ Testing commit c1d9423 with merge 3b49a39fd2d0e933e23d2a0a6e1d6e1baf56e27a...

[rust-log-analyzer]

The job x86_64-gnu failed! Check out the build log: (web) (plain)

Click to see the possible cause of the failure (guessed by this bot)

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stderr:
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thread 'main' panicked at 'assertion failed: voidret1 as extern fn() != voidret2 as extern fn()', /checkout/src/test/ui/extern/extern-compare-with-return-type.rs:17:5

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Some tests failed in compiletest suite=ui mode=ui host=x86_64-unknown-linux-gnu target=x86_64-unknown-linux-gnu


command did not execute successfully: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage0-tools-bin/compiletest" "--compile-lib-path" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/lib" "--run-lib-path" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/lib/rustlib/x86_64-unknown-linux-gnu/lib" "--rustc-path" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "--src-base" "/checkout/src/test/ui" "--build-base" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui" "--stage-id" "stage2-x86_64-unknown-linux-gnu" "--suite" "ui" "--mode" "ui" "--target" "x86_64-unknown-linux-gnu" "--host" "x86_64-unknown-linux-gnu" "--llvm-filecheck" "/checkout/obj/build/x86_64-unknown-linux-gnu/llvm/build/bin/FileCheck" "--host-rustcflags" "-Crpath -O -Cdebuginfo=0 -Zunstable-options  -Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "--target-rustcflags" "-Crpath -O -Cdebuginfo=0 -Zunstable-options  -Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "--docck-python" "/usr/bin/python3" "--lldb-python" "/usr/bin/python3" "--gdb" "/usr/bin/gdb" "--llvm-version" "11.0.1-rust-1.51.0-nightly" "--llvm-components" "aarch64 aarch64asmparser aarch64codegen aarch64desc aarch64disassembler aarch64info aarch64utils aggressiveinstcombine all all-targets analysis arm armasmparser armcodegen armdesc armdisassembler arminfo armutils asmparser asmprinter avr avrasmparser avrcodegen avrdesc avrdisassembler avrinfo binaryformat bitreader bitstreamreader bitwriter cfguard codegen core coroutines coverage debuginfocodeview debuginfodwarf debuginfogsym debuginfomsf debuginfopdb demangle dlltooldriver dwarflinker engine executionengine extensions frontendopenmp fuzzmutate globalisel gtest gtest_main hexagon hexagonasmparser hexagoncodegen hexagondesc hexagondisassembler hexagoninfo instcombine instrumentation interpreter ipo irreader jitlink libdriver lineeditor linker lto mc mca mcdisassembler mcjit mcparser mips mipsasmparser mipscodegen mipsdesc mipsdisassembler mipsinfo mirparser msp430 msp430asmparser msp430codegen msp430desc msp430disassembler msp430info native nativecodegen nvptx nvptxcodegen nvptxdesc nvptxinfo objcarcopts object objectyaml option orcerror orcjit passes powerpc powerpcasmparser powerpccodegen powerpcdesc powerpcdisassembler powerpcinfo profiledata remarks riscv riscvasmparser riscvcodegen riscvdesc riscvdisassembler riscvinfo riscvutils runtimedyld scalaropts selectiondag sparc sparcasmparser sparccodegen sparcdesc sparcdisassembler sparcinfo support symbolize systemz systemzasmparser systemzcodegen systemzdesc systemzdisassembler systemzinfo tablegen target testingsupport textapi transformutils vectorize webassembly webassemblyasmparser webassemblycodegen webassemblydesc webassemblydisassembler webassemblyinfo windowsmanifest x86 x86asmparser x86codegen x86desc x86disassembler x86info xray" "--cc" "" "--cxx" "" "--cflags" "" "--adb-path" "adb" "--adb-test-dir" "/data/tmp/work" "--android-cross-path" "" "--color" "always"


failed to run: /checkout/obj/build/bootstrap/debug/bootstrap --stage 2 test
Build completed unsuccessfully in 0:21:08

[bors]

💔 Test failed - checks-actions

[nikic]

This assertion fails:

rust/src/test/ui/extern/extern-compare-with-return-type.rs

Line 17 in 1f9dc9a

assert!(voidret1 as extern fn() != voidret2 as extern fn());

At a guess, maybe those functions got merged and thus have the same address? Do Rust semantics require that distinct functions have distinct addresses?

[nikic]

Change probably caused by llvm/llvm-project@38399ce, which removes the assumption that distinct unnamed_addr globals have different addresses (as they may be merged).

[nagisa]

At a guess, maybe those functions got merged and thus have the same address? Do Rust semantics require that distinct functions have distinct addresses?

There is no such requirement, no. This assertion is bogus.

[cuviper]

Change probably caused by llvm/llvm-project@38399ce, which removes the assumption that distinct unnamed_addr globals have different addresses (as they may be merged).

This fixed bug 47090, filed by @RalfJung. (cc #73722)

I've added dbg!() to ensure those functions are different (via line number), but I can remove that assertion if you'd rather.

[nikic]

Making the functions different seems fine to me.

@bors r+

[bors]

📌 Commit 9756838 has been approved by nikic

[rylev]

@cuviper It does seem that this PR was responsible for the perf regressions in the rollup where it was merged (#80960) as can be seen here in #81207. I'm guessing it's probably not worth actually addressing this, but we might want to get in the habit of doing perf runs when upgrading LLVM. Thoughts?

[nikic]

Huh, I didn't expect this to happen for a patch version bump. Those are some pretty huge changes. The fact that the main impact is on check builds implies that rustc itself is being optimized worse, in a fairly significant way.

[Mark-Simulacrum]

More broadly, we should definitely not be rolling up LLVM bumps I think.

[nikic]

Though possibly I'm misunderstanding the results. Is the link at #81207 meaningful, or should I be looking at https://perf.rust-lang.org/compare.html?start=058a71016553f267ae80b90276ef79956457d51a&end=3ab423f5ac44d394fb4d47db2b4042b4a25e8b1d&stat=instructions%3Au instead (which looks about neutral)?

[cuviper]

Yeah, it's surprising that a patch release had such impact. We can make a point of separating these from rollups though, sure.

[Mark-Simulacrum]

That said, I think the performance results are unlikely to be due to this PR - the rust-timer generated perf test PR seems to be buggy, as it includes more than just this PR's changes. I've filed rust-lang/rustc-perf#832 to track that.

I think it is plausible there were some LLVM regressions, but the regex regression in the rollup's merge results are likely due to #80922 (Revert "Auto merge of #76896 - spastorino:codegen-inline-fns2) which specifically reverted debug-related codegen changes.