545cdca488
SCCP currently stores instructions whose lattice value has changed in a worklist, and then updates their users in the main loop. This may result in instructions unnecessarily being visited multiple times (as an instruction will often use multiple other instructions). Additionally, we'd often redundantly visit instructions that were already visited when the containing block first became executable. Instead, change the worklist to directly store the instructions that need to be revisited. Additionally, do not add instructions to the worklist that will already be covered by the main basic block walk. This change is conceptually NFC, but is expected to produce minor differences in practice, because the visitation order interacts with the range widening limit.
81 KiB
81 KiB