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| author | Patryk Wychowaniec <pwychowaniec@pm.me> | 2023-07-19 11:54:34 +0800 |
|---|---|---|
| committer | Ben Shi <2283975856@qq.com> | 2023-07-19 11:57:00 +0800 |
| commit | 4e831753b9cf8745e9bf251f775f2399c9ef4138 (patch) | |
| tree | 4d9c238ec51cbbc66cf21cb01b48cea0d14af3e6 /clang/tools/c-index-test/c-index-test.c | |
| parent | eb33db4f9151b3cb87a45d2135b9decc133f3d09 (diff) | |
| download | llvm-4e831753b9cf8745e9bf251f775f2399c9ef4138.zip llvm-4e831753b9cf8745e9bf251f775f2399c9ef4138.tar.gz llvm-4e831753b9cf8745e9bf251f775f2399c9ef4138.tar.bz2 | |
[AVR] Expand shifts of all types except int8 and int16
Currently our AVRShiftExpand pass expands only 32-bit shifts, with the
assumption that other kinds of shifts (e.g. 64-bit ones) are
automatically reduced to 8-bit ones by LLVM during ISel.
However this is not always true and causes problems in the rust-lang runtime.
This commit changes the logic a bit, so that instead of expanding only
32-bit shifts, we expand shifts of all types except 8-bit and 16-bit.
This is not the most optimal solution, because 64-bit shifts can be
expanded to 32-bit shifts which has been deeply optimized.
I've checked the generated code using rustc + simavr, and all shifts
seem to behave correctly.
Spotted in the wild in rustc:
https://github.com/rust-lang/compiler-builtins/issues/523
https://github.com/rust-lang/rust/issues/112140
Reviewed By: benshi001
Differential Revision: https://reviews.llvm.org/D154785
Diffstat (limited to 'clang/tools/c-index-test/c-index-test.c')
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