[X86] Fix killed flag handling in X86FixupLea pass

[skatkov]

Summary

When pass creates a MOV instruction for
lea (%base,%index,1), %dst => mov %base,%dst; add %index,%dst
modification it should clean the killed flag for base if base is equal to index.

Otherwise verifier complains about usage of killed register in add instruction.

lib/Target/X86/X86FixupLEAs.cpp

if (!IsInefficientBase || (!IsInefficientIndex && IsScale1)) {
     return NewMI;
   }
   // Handle the rest of the cases with inefficient base register:
   assert(SSDstR != BaseR && "SSDstR == BaseR should be handled already!");
   assert(IsInefficientBase && "efficient base should be handled already!");
 
   // lea (%base,%index,1), %dst => mov %base,%dst; add %index,%dst
   if (IsScale1 && !hasLEAOffset(Offset)) {
-    TII->copyPhysReg(*MFI, MI, DL, DstR, BaseR, Base.isKill());
+    bool BIK = Base.isKill() && BaseR != IndexR;
+    TII->copyPhysReg(*MFI, MI, DL, DstR, BaseR, BIK);
     DEBUG(MI.getPrevNode()->dump(););
 
     MachineInstr *NewMI =
         BuildMI(*MFI, MI, DL, ADDrr, DstR).addReg(DstR).add(Index);
     DEBUG(NewMI->dump(););
     return NewMI;
   }
   // lea offset(%base,%index,scale), %dst =>

test/CodeGen/X86/leaFixup32.mir

frameInfo:
   hasVAStart:      false
   hasMustTailInVarArgFunc: false
 body:             |
   bb.0 (%ir-block.0):
     liveins: %eax, %ebp, %ebx
     ; CHECK: %ebx = MOV32rr  %ebp
     ; CHECK: %ebx = ADD32rr %ebx, %ebp
  
-    %ebx = LEA32r %ebp, 1, %ebp, 0, %noreg
+    %ebx = LEA32r killed %ebp, 1, %ebp, 0, %noreg
     RETQ %ebx
 
 ...
 ---
 name:            testleaadd_ebp_index_32
 alignment:       4
 exposesReturnsTwice: false
 legalized:       false

test/CodeGen/X86/leaFixup64.mir

frameInfo:
   hasVAStart:      false
   hasMustTailInVarArgFunc: false
 body:             |
   bb.0 (%ir-block.0):
     liveins: %rax, %rbp, %rbx
     ; CHECK: %rbx = MOV64rr %rbp
     ; CHECK: %rbx = ADD64rr %rbx, %rbp
  
-    %rbx = LEA64r %rbp, 1, %rbp, 0, %noreg
+    %rbx = LEA64r killed %rbp, 1, %rbp, 0, %noreg
     RETQ %ebx
 
 ...
 ---
 name:            testleaadd_rbp_index_64
 alignment:       4
 exposesReturnsTwice: false
 legalized:       false