llvm-project

f5c8c1ee - [SLPVectorizer] Move X86 specific handling into X86TTIImpl. (#137830)

[SLPVectorizer] Move X86 specific handling into X86TTIImpl. (#137830) `ad9909d "[SLP]Fix perfect diamond match with extractelements in scalars" ` changed SLPVectorizer getScalarizationOverhead() to call TTI.getVectorInstrCost() instead of TTI.getScalarizationOverhead() in some cases. This was due to X86 specific handlings in these (overridden) methods, and unfortunately the general preference of TTI.getScalarizationOverhead() was dropped. If VL is available it should always be preferred to use getScalarizationOverhead(), and this is indeed the case for SystemZ which has a special insertion instruction that can insert two GPR64s. Then ` 33af951 "[SLP]Synchronize cost of gather/buildvector nodes with codegen"` reworked SLPVectorizer getGatherCost() which together with ad9909d caused the SystemZ test vec-elt-insertion.ll to fail. This patch restores the SystemZ test and reverts the change in SLPVectorizer getScalarizationOverhead() so that TTI.getScalarizationOverhead() is always called again. The ForPoisonSrc argument is now passed on to the TTI method so that X86 can handle this as required. Fixes: #135346