6 Commits

Author SHA1 Message Date
Matt Arsenault
07e34d2de5 JumpThreading: Convert tests to -passes 2022-11-27 11:19:28 -05:00
Matt Arsenault
83d5052768 JumpThreading: Convert tests to opaque pointers
phi-known.ll:test2 required deleting one manual check for a bitcast

Also strip trailing whitespace while we're touching everything.
2022-11-27 11:19:28 -05:00
Hans Wennborg
1e9afab875 Re-apply "[JumpThreading] Ignore free instructions"
It seems the crashes we saw wasn't caused by this (see comments on the review).

> This is basically D108837 but for jump threading. Free instructions
> should be ignored for the threading decision. JumpThreading already
> skips some free instructions (like pointer bitcasts), but does not
> skip various free intrinsics -- in fact, it currently gives them a
> fairly large cost of 2.
>
> Differential Revision: https://reviews.llvm.org/D110290

This reverts commit 4604695d7c20e72b551a1a5224f3de877cb41bd3.
2021-09-24 18:52:30 +02:00
Hans Wennborg
4604695d7c Revert "[JumpThreading] Ignore free instructions"
It caused compiler crashes, see comment on the code review for repro.

> This is basically D108837 but for jump threading. Free instructions
> should be ignored for the threading decision. JumpThreading already
> skips some free instructions (like pointer bitcasts), but does not
> skip various free intrinsics -- in fact, it currently gives them a
> fairly large cost of 2.
>
> Differential Revision: https://reviews.llvm.org/D110290

This reverts commit 1e3c6fc7cb9d2ee6a5328881f95d6643afeadbff.
2021-09-24 16:14:53 +02:00
Nikita Popov
1e3c6fc7cb [JumpThreading] Ignore free instructions
This is basically D108837 but for jump threading. Free instructions
should be ignored for the threading decision. JumpThreading already
skips some free instructions (like pointer bitcasts), but does not
skip various free intrinsics -- in fact, it currently gives them a
fairly large cost of 2.

Differential Revision: https://reviews.llvm.org/D110290
2021-09-23 18:28:36 +02:00
Nikita Popov
d8e1203f91 [JumpThreading] Add test with free instructions (NFC)
Which demonstrates that "free" instructions can prevent jump
threading.
2021-09-22 22:29:39 +02:00