Index: lib/CodeGen/OptimizePHIs.cpp
===================================================================
--- lib/CodeGen/OptimizePHIs.cpp
+++ lib/CodeGen/OptimizePHIs.cpp
@@ -90,10 +90,10 @@
 }
 
 /// IsSingleValuePHICycle - Check if MI is a PHI where all the source operands
-/// are copies of SingleValReg, possibly via copies through other PHIs.  If
+/// are copies of SingleValReg, possibly via copies through other PHIs. If
 /// SingleValReg is zero on entry, it is set to the register with the single
-/// non-copy value.  PHIsInCycle is a set used to keep track of the PHIs that
-/// have been scanned.
+/// non-copy value. PHIsInCycle is a set used to keep track of the PHIs that
+/// have been scanned. PHIs may be grouped by cycle, several cycles or chains.
 bool OptimizePHIs::IsSingleValuePHICycle(MachineInstr *MI,
                                          unsigned &SingleValReg,
                                          InstrSet &PHIsInCycle) {
@@ -119,8 +119,10 @@
     if (SrcMI && SrcMI->isCopy() &&
         !SrcMI->getOperand(0).getSubReg() &&
         !SrcMI->getOperand(1).getSubReg() &&
-        TargetRegisterInfo::isVirtualRegister(SrcMI->getOperand(1).getReg()))
-      SrcMI = MRI->getVRegDef(SrcMI->getOperand(1).getReg());
+        TargetRegisterInfo::isVirtualRegister(SrcMI->getOperand(1).getReg())) {
+      SrcReg = SrcMI->getOperand(1).getReg();
+      SrcMI = MRI->getVRegDef(SrcReg);
+    }
     if (!SrcMI)
       return false;
 
@@ -129,7 +131,7 @@
         return false;
     } else {
       // Fail if there is more than one non-phi/non-move register.
-      if (SingleValReg != 0)
+      if (SingleValReg != 0 && SingleValReg != SrcReg)
         return false;
       SingleValReg = SrcReg;
     }
@@ -180,6 +182,9 @@
       if (!MRI->constrainRegClass(SingleValReg, MRI->getRegClass(OldReg)))
         continue;
 
+      // for the case SingleValReg taken from copy instr
+      MRI->clearKillFlags(SingleValReg);
+
       MRI->replaceRegWith(OldReg, SingleValReg);
       MI->eraseFromParent();
       ++NumPHICycles;
Index: test/CodeGen/X86/madd.ll
===================================================================
--- test/CodeGen/X86/madd.ll
+++ test/CodeGen/X86/madd.ll
@@ -427,8 +427,7 @@
 ; AVX1-NEXT:    vextractf128 $1, %ymm1, %xmm4
 ; AVX1-NEXT:    vextractf128 $1, %ymm0, %xmm5
 ; AVX1-NEXT:    vextractf128 $1, %ymm2, %xmm2
-; AVX1-NEXT:    vextractf128 $1, %ymm0, %xmm6
-; AVX1-NEXT:    vpaddd %xmm6, %xmm2, %xmm2
+; AVX1-NEXT:    vpaddd %xmm5, %xmm2, %xmm2
 ; AVX1-NEXT:    vpaddd %xmm2, %xmm5, %xmm2
 ; AVX1-NEXT:    vpaddd %xmm2, %xmm4, %xmm2
 ; AVX1-NEXT:    vpaddd %xmm3, %xmm0, %xmm0
@@ -1036,8 +1035,7 @@
 ; AVX1-NEXT:    vextractf128 $1, %ymm1, %xmm4
 ; AVX1-NEXT:    vextractf128 $1, %ymm0, %xmm5
 ; AVX1-NEXT:    vextractf128 $1, %ymm2, %xmm2
-; AVX1-NEXT:    vextractf128 $1, %ymm0, %xmm6
-; AVX1-NEXT:    vpaddd %xmm6, %xmm2, %xmm2
+; AVX1-NEXT:    vpaddd %xmm5, %xmm2, %xmm2
 ; AVX1-NEXT:    vpaddd %xmm2, %xmm5, %xmm2
 ; AVX1-NEXT:    vpaddd %xmm2, %xmm4, %xmm2
 ; AVX1-NEXT:    vpaddd %xmm3, %xmm0, %xmm0
Index: test/CodeGen/X86/opt_phis2.mir
===================================================================
--- /dev/null
+++ test/CodeGen/X86/opt_phis2.mir
@@ -0,0 +1,72 @@
+# RUN: llc -run-pass opt-phis -march=x86-64 -o - %s | FileCheck %s
+# All PHIs should be removed since they can be securely replaced
+# by %8 register.
+# CHECK-NOT: PHI
+--- |
+  define void @test() {
+    ret void
+  }
+...
+---
+name:            test
+alignment:       4
+tracksRegLiveness: true
+jumpTable:
+  kind:            block-address
+  entries:
+    - id:              0
+      blocks:          [ '%bb.3', '%bb.2', '%bb.1', '%bb.4' ]
+body:             |
+  bb.0:
+    liveins: $edi, $ymm0, $rsi
+
+    %9:gr64 = COPY $rsi
+    %8:vr256 = COPY $ymm0
+    %7:gr32 = COPY $edi
+    %11:gr32 = SAR32ri %7, 31, implicit-def dead $eflags
+    %12:gr32 = SHR32ri %11, 30, implicit-def dead $eflags
+    %13:gr32 = ADD32rr %7, killed %12, implicit-def dead $eflags
+    %14:gr32 = AND32ri8 %13, -4, implicit-def dead $eflags
+    %15:gr32 = SUB32rr %7, %14, implicit-def dead $eflags
+    %10:gr64_nosp = SUBREG_TO_REG 0, %15, %subreg.sub_32bit
+    %16:gr32 = SUB32ri8 %15, 3, implicit-def $eflags
+    JA_1 %bb.8, implicit $eflags
+
+  bb.9:
+    JMP64m $noreg, 8, %10, %jump-table.0, $noreg :: (load 8 from jump-table)
+
+  bb.1:
+    %0:vr256 = COPY %8
+    JMP_1 %bb.5
+
+  bb.2:
+    %1:vr256 = COPY %8
+    JMP_1 %bb.6
+
+  bb.3:
+    %2:vr256 = COPY %8
+    JMP_1 %bb.7
+
+  bb.4:
+    %3:vr256 = COPY %8
+    %17:vr128 = VEXTRACTF128rr %8, 1
+    VPEXTRDmr %9, 1, $noreg, 12, $noreg, killed %17, 2
+
+  bb.5:
+    %4:vr256 = PHI %0, %bb.1, %3, %bb.4
+    %18:vr128 = VEXTRACTF128rr %4, 1
+    VPEXTRDmr %9, 1, $noreg, 8, $noreg, killed %18, 1
+
+  bb.6:
+    %5:vr256 = PHI %1, %bb.2, %4, %bb.5
+    %19:vr128 = VEXTRACTF128rr %5, 1
+    VMOVPDI2DImr %9, 1, $noreg, 4, $noreg, killed %19
+
+  bb.7:
+    %6:vr256 = PHI %2, %bb.3, %5, %bb.6
+    %20:vr128 = COPY %6.sub_xmm
+    VPEXTRDmr %9, 1, $noreg, 0, $noreg, killed %20, 3
+
+  bb.8:
+    RET 0
+...
Index: test/CodeGen/X86/sad.ll
===================================================================
--- test/CodeGen/X86/sad.ll
+++ test/CodeGen/X86/sad.ll
@@ -307,9 +307,7 @@
 ; AVX1-NEXT:    vpaddd %xmm0, %xmm0, %xmm2
 ; AVX1-NEXT:    vextractf128 $1, %ymm1, %xmm3
 ; AVX1-NEXT:    vextractf128 $1, %ymm0, %xmm4
-; AVX1-NEXT:    vextractf128 $1, %ymm0, %xmm5
-; AVX1-NEXT:    vextractf128 $1, %ymm0, %xmm6
-; AVX1-NEXT:    vpaddd %xmm6, %xmm5, %xmm5
+; AVX1-NEXT:    vpaddd %xmm4, %xmm4, %xmm5
 ; AVX1-NEXT:    vpaddd %xmm5, %xmm4, %xmm4
 ; AVX1-NEXT:    vpaddd %xmm4, %xmm3, %xmm3
 ; AVX1-NEXT:    vpaddd %xmm2, %xmm0, %xmm0