[X86] Fix killed flag handling in X86FixupLea pass

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.

Reviewers: lsaba, zvi, zansari, aaboud
Reviewed By: lsaba
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D42522

llvm-svn: 323497

Author: Serguei Katkov

llvm/lib/Target/X86/X86FixupLEAs.cpp

@@ -548,7 +548,8 @@ FixupLEAPass::processInstrForSlow3OpLEA(MachineInstr &MI,
 
   // 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 =

llvm/test/CodeGen/X86/leaFixup32.mir

@@ -354,7 +354,7 @@ body:             |
     ; 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
 
 ...

llvm/test/CodeGen/X86/leaFixup64.mir

@@ -810,7 +810,7 @@ body:             |
     ; 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
 
 ...