llvm-project

Commit Graph

Author	SHA1	Message	Date
Nikita Popov	8fdd7c2ff1	[LoopUnroll] Clamp unroll count to MaxTripCount Unrolling with more iterations than MaxTripCount is pointless, as those iterations can never be executed. As such, we clamp ULO.Count to MaxTripCount if it is known. This means we no longer need to consider iterations after MaxTripCount for exit folding, and the CompletelyUnroll flag becomes independent of ULO.TripCount. Differential Revision: https://reviews.llvm.org/D103748	2021-06-07 21:08:42 +02:00
Sam Parker	dad04e62f1	[NFC] run update test script On Transforms/LoopUnroll/runtime-small-upperbound.ll	2020-08-17 13:54:28 +01:00
Zhaoshi Zheng	1128fa0924	[Unroll] Do NOT unroll a loop with small runtime upperbound For a runtime loop if we can compute its trip count upperbound: Don't unroll if: 1. loop is not guaranteed to run either zero or upperbound iterations; and 2. trip count upperbound is less than UnrollMaxUpperBound Unless user or TTI asked to do so. If unrolling, limit unroll factor to loop's trip count upperbound. Differential Revision: https://reviews.llvm.org/D62989 Change-Id: I6083c46a9d98b2e22cd855e60523fdc5a4929c73 llvm-svn: 373017	2019-09-26 21:40:27 +00:00

Author

SHA1

Message

Date

Nikita Popov

8fdd7c2ff1

[LoopUnroll] Clamp unroll count to MaxTripCount

Unrolling with more iterations than MaxTripCount is pointless, as
those iterations can never be executed. As such, we clamp ULO.Count
to MaxTripCount if it is known. This means we no longer need to
consider iterations after MaxTripCount for exit folding, and the
CompletelyUnroll flag becomes independent of ULO.TripCount.

Differential Revision: https://reviews.llvm.org/D103748

2021-06-07 21:08:42 +02:00

Sam Parker

dad04e62f1

[NFC] run update test script

On Transforms/LoopUnroll/runtime-small-upperbound.ll

2020-08-17 13:54:28 +01:00

Zhaoshi Zheng

1128fa0924

[Unroll] Do NOT unroll a loop with small runtime upperbound

For a runtime loop if we can compute its trip count upperbound:

Don't unroll if:
1. loop is not guaranteed to run either zero or upperbound iterations; and
2. trip count upperbound is less than UnrollMaxUpperBound
Unless user or TTI asked to do so.

If unrolling, limit unroll factor to loop's trip count upperbound.

Differential Revision: https://reviews.llvm.org/D62989

Change-Id: I6083c46a9d98b2e22cd855e60523fdc5a4929c73
llvm-svn: 373017

2019-09-26 21:40:27 +00:00

3 Commits