Commit Graph

6 Commits

Author SHA1 Message Date
Max Kazantsev 160a453138 Return "[IndVars] Remove monotonic checks with unknown exit count"
This reverts commit e038b60d91.
This reverts commit a0d84d8031.

This revert was a mistake. The reason of the failures was
"Use uint64_t for branch weights instead of uint32_t"

Differential Revision: https://reviews.llvm.org/D87832
2020-10-28 18:51:40 +07:00
Raphael Isemann e038b60d91 Revert "[IndVars] Remove monotonic checks with unknown exit count"
This reverts commit c6ca26c0bf.
This breaks stage2 builds due to hitting this assert:
```
   Assertion failed: (WeightSum <= UINT32_MAX && "Expected weights to scale down to 32 bits"), function calcMetadataWeights
```
when compiling AArch64RegisterBankInfo.cpp in LLVM.
2020-10-27 15:31:37 +01:00
Max Kazantsev c6ca26c0bf [IndVars] Remove monotonic checks with unknown exit count
Even if the exact exit count is unknown, we can still prove that this
exit will not be taken. If we can prove that the predicate is monotonic,
fulfilled on first & last iteration, and no overflow happened in between,
then the check can be removed.

Differential Revision: https://reviews.llvm.org/D87832
Reviewed By: apilipenko
2020-10-27 11:35:16 +07:00
Max Kazantsev 046f240202 [Test] More tests where IndVars fails to eliminate a range check 2020-09-08 14:43:29 +07:00
Max Kazantsev 8784e9016d [Test] Range fix in test
test02_neg is not testing what it claims to test because its starting
value -1 lies outside of specified range.
2020-09-04 19:28:58 +07:00
Max Kazantsev 159f9a69b4 [Test] Add test showing some simple cases that IndVarSimplify does not cover 2020-09-03 18:35:26 +07:00