4 Commits

Author	SHA1	Message	Date
James Molloy	57d9dfa9ac	[ARM] ADD with a negative offset can become SUB for free ... So model that directly in TTI::getIntImmCost(). llvm-svn: 281044	2016-09-09 13:35:36 +00:00
James Molloy	1454e90f86	[ARM] icmp %x, -C can be lowered to a simple ADDS or CMN ... Tell TargetTransformInfo about this so ConstantHoisting is informed. llvm-svn: 281043	2016-09-09 13:35:28 +00:00
James Molloy	753c18f5c0	[Thumb1] AND with a constant operand can be converted into BIC ... So model the cost of materializing the constant operand C as the minimum of C and ~C. llvm-svn: 280929	2016-09-08 12:58:12 +00:00
James Molloy	7c7255e40b	[Thumb1] Fix cost calculation for complemented immediates ... Materializing something like "-3" can be done as 2 instructions: MOV r0, #3 MVN r0, r0 This has a cost of 2, not 3. It looks like we were already trying to detect this pattern in TII::getIntImmCost(), but were taking the complement of the zero-extended value instead of the sign-extended value which is unlikely to ever produce a number < 256. There were no tests failing after changing this... :/ llvm-svn: 280928	2016-09-08 12:58:04 +00:00