Commit Graph

7 Commits

Author SHA1 Message Date
Roman Lebedev 2f80ea7f4f
[NFC][LV] Use different braces in debug output
The analysis passes output function name encapsulated in `'` braces,
but LV uses `"`. Harmonizing this may help in creating an update script
for the LV costmodel test checks.

Reviewed By: fhahn

Differential Revision: https://reviews.llvm.org/D121105
2022-03-07 19:32:37 +03:00
Sander de Smalen b1ff20fd35 [LV] Enable scalable vectorization by default for SVE cores.
The availability of SVE should be sufficient to enable scalable
auto-vectorization.

This patch adds a new TTI interface to query the target what style of
vectorization it wants when scalable vectors are available. For other
targets than AArch64, this currently defaults to 'FixedWidthOnly'.

Differential Revision: https://reviews.llvm.org/D115651
2021-12-20 16:23:29 +00:00
Cullen Rhodes 698584f89b [IR] Remove unbounded as possible value for vscale_range minimum
The default for min is changed to 1. The behaviour of -mvscale-{min,max}
in Clang is also changed such that 16 is the max vscale when targeting
SVE and no max is specified.

Reviewed By: sdesmalen, paulwalker-arm

Differential Revision: https://reviews.llvm.org/D113294
2021-12-07 09:52:21 +00:00
Sander de Smalen 2829376bb2 [LV] Use VScaleForTuning to fine-tune the cost per lane.
When targeting a specific CPU with scalable vectorization, the knowledge
of that particular CPU's vscale value can be used to tune the cost-model
and make the cost per lane less pessimistic.

If the target implements 'TTI.getVScaleForTuning()', the cost-per-lane
is calculated as:

  Cost / (VScaleForTuning * VF.KnownMinLanes)

Otherwise, it assumes a value of 1 meaning that the behavior
is unchanged and calculated as:

  Cost / VF.KnownMinLanes

Reviewed By: kmclaughlin, david-arm

Differential Revision: https://reviews.llvm.org/D113209
2021-11-08 16:59:46 +00:00
Dylan Fleming ef198cd99e [SVE] Remove usage of getMaxVScale for AArch64, in favour of IR Attribute
Removed AArch64 usage of the getMaxVScale interface, replacing it with
the vscale_range(min, max) IR Attribute.

Reviewed By: paulwalker-arm

Differential Revision: https://reviews.llvm.org/D106277
2021-08-17 14:42:47 +01:00
Sander de Smalen d41cb6bb26 [LV] Build and cost VPlans for scalable VFs.
This patch uses the calculated maximum scalable VFs to build VPlans,
cost them and select a suitable scalable VF.

Reviewed By: paulwalker-arm

Differential Revision: https://reviews.llvm.org/D98722
2021-06-02 14:47:47 +01:00
Sander de Smalen 1e6630311c NFC: cleaned up and renamed scalable-vf-analysis.ll -> scalable-vectorization.ll
* Removes unnecessary loop hints.
* Use RUN line with '-scalable-vectorization=preferred' instead of 'on'
  for the maximize-bandwidth behaviour. This prepares the test for enabling
  scalable vectorization; With a forced instruction-cost of 1, 'on' will
  always favour fixed-width VF to be chosen, whereas with 'preferred'
  we can check that the maximize-bandwidth option in combination with
  scalable-vectorization=preferred actually picks a scalable VF.
* Renamed to scalable-vectorization.ll, because a follow-up patch will
  test more than just analysis.
2021-05-23 19:53:51 +01:00