Extended Description

Testcase:

define <128 x i32> @​ret_split_v128i32(<128 x i32>* %x) {
%v = load <128 x i32>, <128 x i32>* %x
ret <128 x i32> %v
}

This testcase is extracted from llvm/test/CodeGen/RISCV/rvv/fixed-vectors-calling-conv.ll

Execution command:

llc -mtriple=riscv64 -mattr=+experimental-v -riscv-v-vector-bits-min=128 -riscv-v-fixed-length-vector-lmul-max=4 -pre-RA-sched=list-burr foo.ll --disable-machine-cse test.ll

Change schedule policy for pre-RA to list-burr and disable machine-cse.

Execution result:

Use of %2 does not have a corresponding definition on every path: 48r %3:gpr = ADDI %2:gpr, 448 LLVM ERROR: Use not jointly dominated by defs.
PLEASE submit a bug report to https://bugs.llvm.org/ and include the crash backtrace. Stack dump:
...

I think this bug is that DemoteRegister copied out in return bb doesn't be chained with DemoteRegister copied in in entry bb.