[llvm] [LV][EVL] Disable fixed-order recurrence idiom with EVL tail folding. (PR #122458)

[Mel Chen via llvm-commits]

Mel-Chen wrote:

> The title should probably say `Fixes https://github.com/llvm/llvm-project/issues/122461` to close it on commit.

I originally planned to close issues/122461 only after the actual fix is implemented. Should I close the issue in this temporary fix?

> I'm curious if testing could be improved to catch things like this earlier. As this is part of llvm-test-suite, does this mean that there isn't any automatic runtime testing running llvm-test-suite with EVL mode enabled?

https://lab.llvm.org/staging/#/builders/16 has enabled EVL tail folding, but it doesn’t test the LLVM test suite yet. Maybe we could enable it later? @asb cc: @mshockwave 

Currently, we are addressing and cleaning up all LLVM test-suite failures. Initially, there were 7 failures, with 3 related to fixed-order recurrence. We are still investigating the causes of the remaining 4 failures and working on fixes.


https://github.com/llvm/llvm-project/pull/122458