llvm-project

6cccea98 - [CodeGen] Allow inserting a block that starts with debug instructions in SlotIndexes (#233453)

[CodeGen] Allow inserting a block that starts with debug instructions in SlotIndexes (#233453) SlotIndexes::insertMBBInMaps used the index of the new block's first instruction to decide where to insert the block's start entry. Debug and pseudo probe instructions have no index, so splitting a block with LiveIntervals available crashed if the new block started with one. For example, SIWholeQuadMode splits a block after a lowered demote, and a DBG_VALUE following the demote made llc crash with -g. Use the first instruction that has an index instead, or the end of the previous block if there is none. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>