s390: Do not waste a register when assigning a constant to a memory
location. If available, use MVHI and friends. If those are not available,
load the constant value into register r0 and store that. r0 is not visible
to register allocation and therefore using it does not increase register
pressure.
Remove S390_INSN_MZERO and replace it with S390_INSN_MIMM. Assigning zero
is just a special case..
Saves between 0.9% and 2.4% of insns as measured with the perf regression
bucket.
git-svn-id: svn://svn.valgrind.org/vex/trunk@2619 8f6e269a-dfd6-0310-a8e1-e2731360e62c
3 files changed
