6 Commits

Author	SHA1	Message	Date
Simon Pilgrim	c1efdbcbe0	[ValueTracking] Add computeKnownBits DemandedElts support to shift instructions (PR36319)	2020-03-20 11:08:08 +00:00
Simon Pilgrim	95b6f62efb	[InstSimplify] Add some vector shift tests to show lack of DemandedElts support	2020-03-19 22:09:51 +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
Sanjay Patel	d511dde2ec	[InstCombine / InstSimplify] add and move tests for lshr transforms; NFC ... llvm-svn: 291970	2017-01-13 22:54:12 +00:00
Sanjay Patel	6786bc5390	[InstSimplify] use computeKnownBits on shift amount operands ... Do simplifications common to all shift instructions based on the amount shifted: 1. If the shift amount is known larger than the bitwidth, the result is undefined. 2. If the valid bits of the shift amount are all known to be 0, it's a shift by zero, so the shift operand is the result. Note that we could generalize the shift-by-zero transform into a shift-by-constant if all of the valid bits in the shift amount are known, but that would have to be done in InstCombine rather than here because it would mean we need to create a new shift instruction. Differential Revision: http://reviews.llvm.org/D19874 llvm-svn: 269114	2016-05-10 20:46:54 +00:00