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Sanjay Patel e32bd35120 [CostModel] mostly remove cost-kind predicate for intrinsics in basic TTI implementation This is re-applying a combination of `f7eac51b9b` and `8ec7ea3ddc` as one patch to avoid regressions now that we have better testing in place. Those were reverted with `32dd5870ee` because of crashing in experimental intrinsics. That bug should be fixed with `7ae346434`. Paraphrased original commit messages: This is the last step in removing cost-kind as a consideration in the basic class model for intrinsics. See D89461 for the start of that. Subsequent commits dealt with each of the special-case intrinsics that had customization here in the basic class. This should remove a barrier to retrying D87188 (canonicalization to the abs intrinsic). The ARM and x86 cost diffs seen here may be wrong because the target-specific overrides have their own bugs, but we hope this is less wrong - if something has a significant throughput cost, then it should have a significant size / blended cost too by default. The only behavioral diff in current regression tests is shown in the x86 scatter-gather test (which is misplaced or broken because it runs the entire -O3 pipeline) - we unrolled less, and we assume that is a improvement. Exception: in general, we want the size cost for a scalar call to be cheap even if the other costs are expensive - we expect it to just be a branch with some optional stack manipulation. It is likely that we will want to carve out some exceptions/overrides to this rule as follow-up patches for calls that have some general and/or target-specific difference to the expected lowering. This was noticed as a regression in unrolling, so we have a test for that now along with a couple of direct cost model tests. If the assumed scalarization costs for the oversized vector calls are not realistic, that would be another follow-up refinement of the cost models. Differential Revision: https://reviews.llvm.org/D90554	2020-11-20 11:21:10 -05:00
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llvm	[CostModel] mostly remove cost-kind predicate for intrinsics in basic TTI implementation	2020-11-20 11:21:10 -05:00
llvm-c	C API: support scalable vectors	2020-10-28 18:19:34 -04:00

Sanjay Patel e32bd35120 [CostModel] mostly remove cost-kind predicate for intrinsics in basic TTI implementation

This is re-applying a combination of f7eac51b9b and 8ec7ea3ddc as one patch
to avoid regressions now that we have better testing in place.

Those were reverted with 32dd5870ee because of crashing in experimental intrinsics.
That bug should be fixed with 7ae346434.

Paraphrased original commit messages:

This is the last step in removing cost-kind as a consideration in the
basic class model for intrinsics.
See D89461 for the start of that.
Subsequent commits dealt with each of the special-case intrinsics that
had customization here in the basic class. This should remove a barrier
to retrying D87188 (canonicalization to the abs intrinsic).

The ARM and x86 cost diffs seen here may be wrong because the
target-specific overrides have their own bugs, but we hope this is
less wrong - if something has a significant throughput cost, then it
should have a significant size / blended cost too by default.

The only behavioral diff in current regression tests is shown in the
x86 scatter-gather test (which is misplaced or broken because it runs
the entire -O3 pipeline) - we unrolled less, and we assume that is
a improvement.

Exception: in general, we want the *size* cost for a scalar call to be
cheap even if the other costs are expensive - we expect it to just be
a branch with some optional stack manipulation.

It is likely that we will want to carve out some
exceptions/overrides to this rule as follow-up patches for
calls that have some general and/or target-specific difference
to the expected lowering.

This was noticed as a regression in unrolling, so we have a test
for that now along with a couple of direct cost model tests.

If the assumed scalarization costs for the oversized vector
calls are not realistic, that would be another follow-up
refinement of the cost models.

Differential Revision: https://reviews.llvm.org/D90554

2020-11-20 11:21:10 -05:00

llvm [CostModel] mostly remove cost-kind predicate for intrinsics in basic TTI implementation 2020-11-20 11:21:10 -05:00

llvm-c C API: support scalable vectors 2020-10-28 18:19:34 -04:00