[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... :/
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@280928 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed