Compiler crash when compiling for Armv5

[colemancda]

Description

Compiling the Swift StdLib forarmv5-unknown-linux-gnueabi is currently failing with a compiler crash when the Synchronization module is enabled.

Reproduction

Cross compile the Swift Standard Library for armv5-unknown-linux-gnueabi with -DSWIFT_ENABLE_SYNCHRONIZATION=ON.

Stack dump

1.	Swift version 6.0.3 (swift-6.0.3-RELEASE)
2.	Compiling with effective version 5.10
3.	Running pass 'Function Pass Manager' on module '/workspaces/buildroot/output/build/swift-6.0.3/build/stdlib/public/Synchronization/LINUX/armv5/Synchronization.o'.
4.	Running pass 'ARM Instruction Selection' on function '@"$s15Synchronization12_MutexHandleV9_lockSlowyys6UInt32VF"'
Stack dump without symbol names (ensure you have llvm-symbolizer in your PATH or set the environment var `LLVM_SYMBOLIZER_PATH` to point to it):
0  swift-frontend 0x000055c1d7b05bc7
1  swift-frontend 0x000055c1d7b03b8e
2  swift-frontend 0x000055c1d7b0623a
3  libc.so.6      0x00007f48e0fc3520
4  libc.so.6      0x00007f48e10179fc pthread_kill + 300
5  libc.so.6      0x00007f48e0fc3476 raise + 22
6  libc.so.6      0x00007f48e0fa97f3 abort + 211
7  swift-frontend 0x000055c1d20c1b6d
8  swift-frontend 0x000055c1d7a65a4b
9  swift-frontend 0x000055c1d47a6da0
10 swift-frontend 0x000055c1d47a631d
11 swift-frontend 0x000055c1d3d51c77
12 swift-frontend 0x000055c1d479dd9f
13 swift-frontend 0x000055c1d479d420
14 swift-frontend 0x000055c1d479c6b1
15 swift-frontend 0x000055c1d479a29b
16 swift-frontend 0x000055c1d3d4ef71
17 swift-frontend 0x000055c1d52e2b28
18 swift-frontend 0x000055c1d77da481
19 swift-frontend 0x000055c1d77e1693
20 swift-frontend 0x000055c1d77db010
21 swift-frontend 0x000055c1d21f5611
22 swift-frontend 0x000055c1d21f4c60
23 swift-frontend 0x000055c1d1e4f00b
24 swift-frontend 0x000055c1d1e4a630
25 swift-frontend 0x000055c1d1e4957b
26 swift-frontend 0x000055c1d1e4bf6b
27 swift-frontend 0x000055c1d1e4b1d6
28 swift-frontend 0x000055c1d1c223b7
29 libc.so.6      0x00007f48e0faad90
30 libc.so.6      0x00007f48e0faae40 __libc_start_main + 128
31 swift-frontend 0x000055c1d1c20ad5

Expected behavior

This crash is not reproducible when cross compiling for Armv7, Arm64 or x86_64.

Environment

swift-6.0.3-RELEASE
swift:6.0.3-jammy Docker image

Additional information

The Swift StdLib cross compilation scripts are found in MillerTechnologyPeru/buildroot-swift. The crash logs are attached.

logs_32337350484.zip

[colemancda]

The error seems to be determined by the lack of wfe support in Armv5, and there doesn't seem to be a simple way to differentiate the different arm architecture versions.

swift/stdlib/public/Synchronization/Mutex/SpinLoopHint.swift

Line 80 in 55189ba

#if arch(arm) || arch(arm64) || arch(arm64_32)