[qt/clang/llvm]: Summary of bulk changes made

Git repository change summary for qt/clang/llvm
Pushed by mirror-service into branch 'upstream/users/arsenm/clang/driver-amdgpu-avoid-redundant-target-cpu'.
Changed from 973067de2e3b5038e44a0d022fb9f94f00f307c6 to 37beabbfbd8cfa038aebd81ca7a1b58eefdcf270
Acknowledgement was received that this change introduces only existing code that has been pushed to another public open source repository.

This change contains the following new commits:

Git commit 818c7c50cc00b37ae86fa5b2487fa347778305cc by Matt Arsenault on 22/07/2026 at 15:38..
clang: Start using new amdgpu subarch triples

Fixup invocations using --target=amdgcn + -mcpu to introduce
the subarch in the triple.

For offload toolchains, a single toolchain is constructed for the
top level amdgpu architecture, and the effective triple is used for
target specific tool invocations.

The specifics of the resource directory layout are tbd. This does
try to find resources in the subarch named directory. The paths
are searched at toolchain creation time, so that does not work
when there are multiple subarches.

Fixes #154925
https://invent.kde.org/qt/clang/llvm/-/commit/818c7c50cc00b37ae86fa5b2487fa347778305cc

Git commit 37beabbfbd8cfa038aebd81ca7a1b58eefdcf270 by Matt Arsenault on 22/07/2026 at 15:38..
clang/AMDGPU: Stop passing redundant -target-cpu to cc1

Now that the exact target is encoded in the triple's subarch field,
-target-cpu is redundant. This avoids polluting the resultant IR with
unwanted "target-cpu" attributes. The net result is the desired codegen
when compiling libraries for a major subarch and linking it into a
program compiled for a specific arch. e.g., compiling for "gfx9-generic"
would pollute the IR with "target-cpu"="gfx9-generic", so codegen
would ultimately be performed for the generic target even after
linking into the concrete gfx9 cpu. The specialization will now be
achieved by merging the triples without the linker or optimization
passes needing to fixup function attributes.
https://invent.kde.org/qt/clang/llvm/-/commit/37beabbfbd8cfa038aebd81ca7a1b58eefdcf270