forked from OSchip/llvm-project
538a8f0227
As discussed in D76983, that patch can turn a chain of insert/extract with scalar trunc ops into bitcast+extract and existing instcombine vector transforms end up creating a shuffle out of that (see the PhaseOrdering test for an example). Currently, that process requires at least this sequence: -instcombine -early-cse -instcombine. Before D76983, the sequence of insert/extract would reach the SLP vectorizer and become a vector trunc there. Based on a small sampling of public targets/types, converting the shuffle to a trunc is better for codegen in most cases (and a regression of that form is the reason this was noticed). The trunc is clearly better for IR-level analysis as well. This means that we can induce "spontaneous vectorization" without invoking any explicit vectorizer passes (at least a vector cast op may be created out of scalar casts), but that seems to be the right choice given that we started with a chain of insert/extract, and the backend would expand back to that chain if a target does not support the op. Differential Revision: https://reviews.llvm.org/D77299 |
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| .. | ||
| CMakeLists.txt | ||
| InstCombineAddSub.cpp | ||
| InstCombineAndOrXor.cpp | ||
| InstCombineAtomicRMW.cpp | ||
| InstCombineCalls.cpp | ||
| InstCombineCasts.cpp | ||
| InstCombineCompares.cpp | ||
| InstCombineInternal.h | ||
| InstCombineLoadStoreAlloca.cpp | ||
| InstCombineMulDivRem.cpp | ||
| InstCombinePHI.cpp | ||
| InstCombineSelect.cpp | ||
| InstCombineShifts.cpp | ||
| InstCombineSimplifyDemanded.cpp | ||
| InstCombineTables.td | ||
| InstCombineVectorOps.cpp | ||
| InstructionCombining.cpp | ||
| LLVMBuild.txt | ||