Commit Graph

5 Commits

Author SHA1 Message Date
Simon Pilgrim 105e5c940c [ValueTracking] Add DemandedElts support to computeKnownBits/ComputeNumSignBits (PR36319)
This patch adds initial support for a DemandedElts mask to the internal computeKnownBits/ComputeNumSignBits methods, matching the SelectionDAG and GlobalISel equivalents.

So far only a couple of instructions have been setup to handle the DemandedElts, the remainder still using the existing 'all elements' default. The plan is to extend support as we have test coverage.

Differential Revision: https://reviews.llvm.org/D73435
2020-02-01 12:45:46 +00:00
Simon Pilgrim f99ef5455a [InstCombine] Add extra shift(c1,add(c2,y)) tests for PR15141 2020-01-26 19:04:12 +00:00
Eric Christopher cee313d288 Revert "Temporarily Revert "Add basic loop fusion pass.""
The reversion apparently deleted the test/Transforms directory.

Will be re-reverting again.

llvm-svn: 358552
2019-04-17 04:52:47 +00:00
Eric Christopher a863435128 Temporarily Revert "Add basic loop fusion pass."
As it's causing some bot failures (and per request from kbarton).

This reverts commit r358543/ab70da07286e618016e78247e4a24fcb84077fda.

llvm-svn: 358546
2019-04-17 02:12:23 +00:00
Simon Pilgrim 6dd8fab443 [InstCombine] Folding of shifts by the sum of positive values
This patch introduces the combine:

(C1 shift (A add C2)) -> ((C1 shift C2) shift A)
iff A and C2 are both positive

If both A and C2 are know to be positive then we can safely split into 2 shifts, permitting the folding of the Inner shift.

Fix for the spec benchmark case mentioned by @nadav on PR15141 (assuming we can prove that the inputs as positive).

Differential Revision: https://reviews.llvm.org/D26000

llvm-svn: 285696
2016-11-01 15:40:30 +00:00