forked from OSchip/llvm-project
7c04454227
X86 codegen uses function attribute `min-legal-vector-width` to select the proper ABI. The intention of the attribute is to reflect user's requirement when they passing or returning vector arguments. So Clang front-end will iterate the vector arguments and set `min-legal-vector-width` to the width of the maximum for both caller and callee. It is assumed any middle end optimizations won't care of the attribute expect inlining and argument promotion. - For inlining, we will propagate the attribute of inlined functions because the inlining functions become the newer caller. - For argument promotion, we check the `min-legal-vector-width` of the caller and callee and refuse to promote when they don't match. The problem comes from the optimizations' combination, as shown by https://godbolt.org/z/zo3hba8xW. The caller `foo` has two callees `bar` and `baz`. When doing argument promotion, both `foo` and `bar` has the same `min-legal-vector-width`. So the argument was promoted to vector. Then the inlining inlines `baz` to `foo` and updates `min-legal-vector-width`, which results in ABI mismatch between `foo` and `bar`. This patch fixes the problem by expanding the concept of `min-legal-vector-width` to indicator of functions arguments. That says, any passes touch functions arguments have to set `min-legal-vector-width` to the value reflects the width of vector arguments. It makes sense to me because any arguments modifications are ABI related and should response for the ABI compatibility. Differential Revision: https://reviews.llvm.org/D123284 |
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| .. | ||
| X86 | ||
| 2008-02-01-ReturnAttrs.ll | ||
| 2008-07-02-array-indexing.ll | ||
| 2008-09-07-CGUpdate.ll | ||
| 2008-09-08-CGUpdateSelfEdge.ll | ||
| aggregate-promote.ll | ||
| alignment.ll | ||
| alloca-as.ll | ||
| array.ll | ||
| attrs.ll | ||
| basictest.ll | ||
| byval-2.ll | ||
| byval.ll | ||
| chained.ll | ||
| control-flow.ll | ||
| control-flow2.ll | ||
| crash.ll | ||
| dbg.ll | ||
| fp80.ll | ||
| inalloca.ll | ||
| invalidation.ll | ||
| live_called_from_dead.ll | ||
| live_called_from_dead_2.ll | ||
| musttail.ll | ||
| naked_functions.ll | ||
| nonzero-address-spaces.ll | ||
| pr27568.ll | ||
| pr32917.ll | ||
| pr33641_remove_arg_dbgvalue.ll | ||
| profile.ll | ||
| reserve-tbaa.ll | ||
| sret.ll | ||
| tail.ll | ||
| variadic.ll | ||