[X86] Optimization for replacing LEA with MOV at frame index elimination time
Summary:
Replace a LEA instruction of the form 'lea (%esp), %ebx' --> 'mov %esp, %ebx'
MOV is preferable over LEA because usually there are more issue-slots available to execute MOVs than LEAs. Latest processors also support zero-latency MOVs.
Fixes pr29022.
Reviewers: hfinkel, delena, igorb, myatsina, mkuper
Differential Revision: https://reviews.llvm.org/D24705
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282385 91177308-0d34-0410-b5e6-96231b3b80d8
18 files changed