diff --git a/llvm/lib/CodeGen/LiveInterval.cpp b/llvm/lib/CodeGen/LiveInterval.cpp
--- a/llvm/lib/CodeGen/LiveInterval.cpp
+++ b/llvm/lib/CodeGen/LiveInterval.cpp
@@ -445,7 +445,7 @@
 
   while (true) {
     // J has just been advanced to satisfy:
-    assert(J->end >= I->start);
+    assert(J->end > I->start);
     // Check for an overlap.
     if (J->start < I->end) {
       // I and J are overlapping. Find the later start.
@@ -460,11 +460,11 @@
       std::swap(I, J);
       std::swap(IE, JE);
     }
-    // Advance J until J->end >= I->start.
+    // Advance J until J->end > I->start.
     do
       if (++J == JE)
         return false;
-    while (J->end < I->start);
+    while (J->end <= I->start);
   }
 }
 
diff --git a/llvm/test/CodeGen/ARM/neon-copy.ll b/llvm/test/CodeGen/ARM/neon-copy.ll
--- a/llvm/test/CodeGen/ARM/neon-copy.ll
+++ b/llvm/test/CodeGen/ARM/neon-copy.ll
@@ -612,11 +612,11 @@
 define <16 x i8> @test_vcopyq_laneq_swap_s8(<16 x i8> %v1, <16 x i8> %v2) {
 ; CHECK-LABEL: test_vcopyq_laneq_swap_s8:
 ; CHECK:       @ %bb.0:
-; CHECK-NEXT:    vorr q9, q1, q1
-; CHECK-NEXT:    vldr d20, .LCPI53_0
-; CHECK-NEXT:    vorr q8, q0, q0
-; CHECK-NEXT:    vtbl.8 d18, {d17, d18}, d20
-; CHECK-NEXT:    vorr q0, q9, q9
+; CHECK-NEXT:    @ kill: def $q1 killed $q1 killed $q0_q1 def $q0_q1
+; CHECK-NEXT:    vldr d16, .LCPI53_0
+; CHECK-NEXT:    @ kill: def $q0 killed $q0 killed $q0_q1 def $q0_q1
+; CHECK-NEXT:    vtbl.8 d2, {d1, d2}, d16
+; CHECK-NEXT:    vorr q0, q1, q1
 ; CHECK-NEXT:    bx lr
 ; CHECK-NEXT:    .p2align 3
 ; CHECK-NEXT:  @ %bb.1:
diff --git a/llvm/test/CodeGen/BPF/sockex2.ll b/llvm/test/CodeGen/BPF/sockex2.ll
--- a/llvm/test/CodeGen/BPF/sockex2.ll
+++ b/llvm/test/CodeGen/BPF/sockex2.ll
@@ -311,7 +311,7 @@
 ; CHECK-LABEL: bpf_prog2:
 ; CHECK: r0 = *(u16 *)skb[12] # encoding: [0x28,0x00,0x00,0x00,0x0c,0x00,0x00,0x00]
 ; CHECK: r0 = *(u16 *)skb[16] # encoding: [0x28,0x00,0x00,0x00,0x10,0x00,0x00,0x00]
-; CHECK: implicit-def: $r1
+; CHECK: implicit-def: $r8
 ; CHECK: r1 =
 ; CHECK: call 1 # encoding: [0x85,0x00,0x00,0x00,0x01,0x00,0x00,0x00]
 ; CHECK: call 2 # encoding: [0x85,0x00,0x00,0x00,0x02,0x00,0x00,0x00]
diff --git a/llvm/test/CodeGen/X86/muloti.ll b/llvm/test/CodeGen/X86/muloti.ll
--- a/llvm/test/CodeGen/X86/muloti.ll
+++ b/llvm/test/CodeGen/X86/muloti.ll
@@ -15,12 +15,12 @@
 ; CHECK-NEXT:    .cfi_offset %r14, -16
 ; CHECK-NEXT:    movq %rdx, %r11
 ; CHECK-NEXT:    movq %rdi, %r10
-; CHECK-NEXT:    movq %rsi, %rdi
-; CHECK-NEXT:    sarq $63, %rdi
+; CHECK-NEXT:    movq %rsi, %rdx
+; CHECK-NEXT:    sarq $63, %rdx
 ; CHECK-NEXT:    movq %rcx, %r8
-; CHECK-NEXT:    imulq %rdi, %r8
-; CHECK-NEXT:    movq %rdx, %rax
-; CHECK-NEXT:    mulq %rdi
+; CHECK-NEXT:    imulq %rdx, %r8
+; CHECK-NEXT:    movq %r11, %rax
+; CHECK-NEXT:    mulq %rdx
 ; CHECK-NEXT:    movq %rdx, %rdi
 ; CHECK-NEXT:    movq %rax, %rbx
 ; CHECK-NEXT:    addq %rax, %rdi
diff --git a/llvm/test/CodeGen/X86/smulo-128-legalisation-lowering.ll b/llvm/test/CodeGen/X86/smulo-128-legalisation-lowering.ll
--- a/llvm/test/CodeGen/X86/smulo-128-legalisation-lowering.ll
+++ b/llvm/test/CodeGen/X86/smulo-128-legalisation-lowering.ll
@@ -16,12 +16,12 @@
 ; X64-NEXT:    .cfi_offset %r15, -16
 ; X64-NEXT:    movq %rdx, %rbx
 ; X64-NEXT:    movq %rdi, %r11
-; X64-NEXT:    movq %rsi, %rdi
-; X64-NEXT:    sarq $63, %rdi
+; X64-NEXT:    movq %rsi, %rdx
+; X64-NEXT:    sarq $63, %rdx
 ; X64-NEXT:    movq %rcx, %r9
-; X64-NEXT:    imulq %rdi, %r9
-; X64-NEXT:    movq %rdx, %rax
-; X64-NEXT:    mulq %rdi
+; X64-NEXT:    imulq %rdx, %r9
+; X64-NEXT:    movq %rbx, %rax
+; X64-NEXT:    mulq %rdx
 ; X64-NEXT:    movq %rdx, %rdi
 ; X64-NEXT:    movq %rax, %r14
 ; X64-NEXT:    addq %rax, %rdi
diff --git a/llvm/test/CodeGen/X86/vec_smulo.ll b/llvm/test/CodeGen/X86/vec_smulo.ll
--- a/llvm/test/CodeGen/X86/vec_smulo.ll
+++ b/llvm/test/CodeGen/X86/vec_smulo.ll
@@ -3310,12 +3310,12 @@
 ; SSE2-NEXT:    movq %rdi, %r10
 ; SSE2-NEXT:    movq {{[0-9]+}}(%rsp), %rsi
 ; SSE2-NEXT:    movq {{[0-9]+}}(%rsp), %rbp
-; SSE2-NEXT:    movq %r11, %rdi
-; SSE2-NEXT:    sarq $63, %rdi
+; SSE2-NEXT:    movq %r11, %rdx
+; SSE2-NEXT:    sarq $63, %rdx
 ; SSE2-NEXT:    movq %r9, %rbx
-; SSE2-NEXT:    imulq %rdi, %rbx
+; SSE2-NEXT:    imulq %rdx, %rbx
 ; SSE2-NEXT:    movq %r15, %rax
-; SSE2-NEXT:    mulq %rdi
+; SSE2-NEXT:    mulq %rdx
 ; SSE2-NEXT:    movq %rdx, %rdi
 ; SSE2-NEXT:    movq %rax, %r12
 ; SSE2-NEXT:    addq %rax, %rdi
@@ -3363,12 +3363,12 @@
 ; SSE2-NEXT:    xorl %r15d, %r15d
 ; SSE2-NEXT:    orq %rdx, %r10
 ; SSE2-NEXT:    setne %r15b
-; SSE2-NEXT:    movq %rcx, %r9
-; SSE2-NEXT:    sarq $63, %r9
+; SSE2-NEXT:    movq %rcx, %rdx
+; SSE2-NEXT:    sarq $63, %rdx
 ; SSE2-NEXT:    movq %rbp, %r11
-; SSE2-NEXT:    imulq %r9, %r11
+; SSE2-NEXT:    imulq %rdx, %r11
 ; SSE2-NEXT:    movq %rsi, %rax
-; SSE2-NEXT:    mulq %r9
+; SSE2-NEXT:    mulq %rdx
 ; SSE2-NEXT:    movq %rdx, %r9
 ; SSE2-NEXT:    movq %rax, %r10
 ; SSE2-NEXT:    addq %rax, %r9
@@ -3444,12 +3444,12 @@
 ; SSSE3-NEXT:    movq %rdi, %r10
 ; SSSE3-NEXT:    movq {{[0-9]+}}(%rsp), %rsi
 ; SSSE3-NEXT:    movq {{[0-9]+}}(%rsp), %rbp
-; SSSE3-NEXT:    movq %r11, %rdi
-; SSSE3-NEXT:    sarq $63, %rdi
+; SSSE3-NEXT:    movq %r11, %rdx
+; SSSE3-NEXT:    sarq $63, %rdx
 ; SSSE3-NEXT:    movq %r9, %rbx
-; SSSE3-NEXT:    imulq %rdi, %rbx
+; SSSE3-NEXT:    imulq %rdx, %rbx
 ; SSSE3-NEXT:    movq %r15, %rax
-; SSSE3-NEXT:    mulq %rdi
+; SSSE3-NEXT:    mulq %rdx
 ; SSSE3-NEXT:    movq %rdx, %rdi
 ; SSSE3-NEXT:    movq %rax, %r12
 ; SSSE3-NEXT:    addq %rax, %rdi
@@ -3497,12 +3497,12 @@
 ; SSSE3-NEXT:    xorl %r15d, %r15d
 ; SSSE3-NEXT:    orq %rdx, %r10
 ; SSSE3-NEXT:    setne %r15b
-; SSSE3-NEXT:    movq %rcx, %r9
-; SSSE3-NEXT:    sarq $63, %r9
+; SSSE3-NEXT:    movq %rcx, %rdx
+; SSSE3-NEXT:    sarq $63, %rdx
 ; SSSE3-NEXT:    movq %rbp, %r11
-; SSSE3-NEXT:    imulq %r9, %r11
+; SSSE3-NEXT:    imulq %rdx, %r11
 ; SSSE3-NEXT:    movq %rsi, %rax
-; SSSE3-NEXT:    mulq %r9
+; SSSE3-NEXT:    mulq %rdx
 ; SSSE3-NEXT:    movq %rdx, %r9
 ; SSSE3-NEXT:    movq %rax, %r10
 ; SSSE3-NEXT:    addq %rax, %r9
@@ -3578,12 +3578,12 @@
 ; SSE41-NEXT:    movq %rdi, %r10
 ; SSE41-NEXT:    movq {{[0-9]+}}(%rsp), %rsi
 ; SSE41-NEXT:    movq {{[0-9]+}}(%rsp), %rbp
-; SSE41-NEXT:    movq %r11, %rdi
-; SSE41-NEXT:    sarq $63, %rdi
+; SSE41-NEXT:    movq %r11, %rdx
+; SSE41-NEXT:    sarq $63, %rdx
 ; SSE41-NEXT:    movq %r9, %rbx
-; SSE41-NEXT:    imulq %rdi, %rbx
+; SSE41-NEXT:    imulq %rdx, %rbx
 ; SSE41-NEXT:    movq %r15, %rax
-; SSE41-NEXT:    mulq %rdi
+; SSE41-NEXT:    mulq %rdx
 ; SSE41-NEXT:    movq %rdx, %rdi
 ; SSE41-NEXT:    movq %rax, %r12
 ; SSE41-NEXT:    addq %rax, %rdi
@@ -3631,12 +3631,12 @@
 ; SSE41-NEXT:    xorl %r15d, %r15d
 ; SSE41-NEXT:    orq %rdx, %r10
 ; SSE41-NEXT:    setne %r15b
-; SSE41-NEXT:    movq %rcx, %r9
-; SSE41-NEXT:    sarq $63, %r9
+; SSE41-NEXT:    movq %rcx, %rdx
+; SSE41-NEXT:    sarq $63, %rdx
 ; SSE41-NEXT:    movq %rbp, %r11
-; SSE41-NEXT:    imulq %r9, %r11
+; SSE41-NEXT:    imulq %rdx, %r11
 ; SSE41-NEXT:    movq %rsi, %rax
-; SSE41-NEXT:    mulq %r9
+; SSE41-NEXT:    mulq %rdx
 ; SSE41-NEXT:    movq %rdx, %r9
 ; SSE41-NEXT:    movq %rax, %r10
 ; SSE41-NEXT:    addq %rax, %r9
@@ -3711,12 +3711,12 @@
 ; AVX-NEXT:    movq %rdi, %r10
 ; AVX-NEXT:    movq {{[0-9]+}}(%rsp), %rsi
 ; AVX-NEXT:    movq {{[0-9]+}}(%rsp), %rbp
-; AVX-NEXT:    movq %r11, %rdi
-; AVX-NEXT:    sarq $63, %rdi
+; AVX-NEXT:    movq %r11, %rdx
+; AVX-NEXT:    sarq $63, %rdx
 ; AVX-NEXT:    movq %r9, %rbx
-; AVX-NEXT:    imulq %rdi, %rbx
+; AVX-NEXT:    imulq %rdx, %rbx
 ; AVX-NEXT:    movq %r15, %rax
-; AVX-NEXT:    mulq %rdi
+; AVX-NEXT:    mulq %rdx
 ; AVX-NEXT:    movq %rdx, %rdi
 ; AVX-NEXT:    movq %rax, %r12
 ; AVX-NEXT:    addq %rax, %rdi
@@ -3764,12 +3764,12 @@
 ; AVX-NEXT:    xorl %r15d, %r15d
 ; AVX-NEXT:    orq %rdx, %r10
 ; AVX-NEXT:    setne %r15b
-; AVX-NEXT:    movq %rcx, %r9
-; AVX-NEXT:    sarq $63, %r9
+; AVX-NEXT:    movq %rcx, %rdx
+; AVX-NEXT:    sarq $63, %rdx
 ; AVX-NEXT:    movq %rbp, %r11
-; AVX-NEXT:    imulq %r9, %r11
+; AVX-NEXT:    imulq %rdx, %r11
 ; AVX-NEXT:    movq %rsi, %rax
-; AVX-NEXT:    mulq %r9
+; AVX-NEXT:    mulq %rdx
 ; AVX-NEXT:    movq %rdx, %r9
 ; AVX-NEXT:    movq %rax, %r10
 ; AVX-NEXT:    addq %rax, %r9
@@ -3896,16 +3896,16 @@
 ; AVX512F-NEXT:    orq %rdx, %r10
 ; AVX512F-NEXT:    setne %al
 ; AVX512F-NEXT:    kmovw %eax, %k0
-; AVX512F-NEXT:    movq %r9, %rsi
-; AVX512F-NEXT:    sarq $63, %rsi
-; AVX512F-NEXT:    movq %rbp, %rbx
-; AVX512F-NEXT:    imulq %rsi, %rbx
+; AVX512F-NEXT:    movq %r9, %rdx
+; AVX512F-NEXT:    sarq $63, %rdx
+; AVX512F-NEXT:    movq %rbp, %rsi
+; AVX512F-NEXT:    imulq %rdx, %rsi
 ; AVX512F-NEXT:    movq %r8, %rax
-; AVX512F-NEXT:    mulq %rsi
+; AVX512F-NEXT:    mulq %rdx
 ; AVX512F-NEXT:    movq %rdx, %r10
 ; AVX512F-NEXT:    movq %rax, %r11
 ; AVX512F-NEXT:    addq %rax, %r10
-; AVX512F-NEXT:    addq %rbx, %r10
+; AVX512F-NEXT:    addq %rsi, %r10
 ; AVX512F-NEXT:    movq %rbp, %rax
 ; AVX512F-NEXT:    sarq $63, %rax
 ; AVX512F-NEXT:    movq %rax, %rsi
@@ -4029,16 +4029,16 @@
 ; AVX512BW-NEXT:    orq %rdx, %r10
 ; AVX512BW-NEXT:    setne %al
 ; AVX512BW-NEXT:    kmovd %eax, %k0
-; AVX512BW-NEXT:    movq %r9, %rsi
-; AVX512BW-NEXT:    sarq $63, %rsi
-; AVX512BW-NEXT:    movq %rbp, %rbx
-; AVX512BW-NEXT:    imulq %rsi, %rbx
+; AVX512BW-NEXT:    movq %r9, %rdx
+; AVX512BW-NEXT:    sarq $63, %rdx
+; AVX512BW-NEXT:    movq %rbp, %rsi
+; AVX512BW-NEXT:    imulq %rdx, %rsi
 ; AVX512BW-NEXT:    movq %r8, %rax
-; AVX512BW-NEXT:    mulq %rsi
+; AVX512BW-NEXT:    mulq %rdx
 ; AVX512BW-NEXT:    movq %rdx, %r10
 ; AVX512BW-NEXT:    movq %rax, %r11
 ; AVX512BW-NEXT:    addq %rax, %r10
-; AVX512BW-NEXT:    addq %rbx, %r10
+; AVX512BW-NEXT:    addq %rsi, %r10
 ; AVX512BW-NEXT:    movq %rbp, %rax
 ; AVX512BW-NEXT:    sarq $63, %rax
 ; AVX512BW-NEXT:    movq %rax, %rsi
diff --git a/llvm/unittests/MI/LiveIntervalTest.cpp b/llvm/unittests/MI/LiveIntervalTest.cpp
--- a/llvm/unittests/MI/LiveIntervalTest.cpp
+++ b/llvm/unittests/MI/LiveIntervalTest.cpp
@@ -4,6 +4,7 @@
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineModuleInfo.h"
 #include "llvm/CodeGen/TargetRegisterInfo.h"
+#include "llvm/CodeGen/TargetSubtargetInfo.h"
 #include "llvm/IR/LegacyPassManager.h"
 #include "llvm/InitializePasses.h"
 #include "llvm/MC/TargetRegistry.h"
@@ -14,6 +15,8 @@
 #include "llvm/Target/TargetOptions.h"
 #include "gtest/gtest.h"
 
+#include "../lib/CodeGen/RegisterCoalescer.h"
+
 using namespace llvm;
 
 namespace llvm {
@@ -162,6 +165,26 @@
   MBB.splitAt(SplitInstr, false, &LIS);
 }
 
+/**
+ * Helper function to test for interference between a hard register and a
+ * virtual register live ranges.
+ */
+static bool checkRegUnitInterference(LiveIntervals &LIS,
+                                     const TargetRegisterInfo &TRI,
+                                     const LiveInterval &VirtReg,
+                                     MCRegister PhysReg) {
+  if (VirtReg.empty())
+    return false;
+  CoalescerPair CP(VirtReg.reg(), PhysReg, TRI);
+
+  for (MCRegUnitIterator Units(PhysReg, &TRI); Units.isValid(); ++Units) {
+    const LiveRange &UnitRange = LIS.getRegUnit(*Units);
+    if (VirtReg.overlaps(UnitRange, CP, *LIS.getSlotIndexes()))
+      return true;
+  }
+  return false;
+}
+
 static void liveIntervalTest(StringRef MIRFunc, LiveIntervalTest T) {
   LLVMContext Context;
   std::unique_ptr<LLVMTargetMachine> TM = createTargetMachine();
@@ -683,6 +706,42 @@
   });
 }
 
+TEST(LiveIntervalTest, AdjacentIntervals) {
+  liveIntervalTest(
+      R"MIR(
+    successors: %bb.1, %bb.2
+
+    $vgpr1 = IMPLICIT_DEF
+    S_NOP 0, implicit $vgpr1
+    %1:vgpr_32 = IMPLICIT_DEF
+    %2:vgpr_32 = IMPLICIT_DEF
+    S_CBRANCH_VCCNZ %bb.2, implicit undef $vcc
+    S_BRANCH %bb.1
+  bb.1:
+    $vgpr0, dead renamable $vcc = V_ADD_CO_U32_e64 %1, %2, 0, implicit $exec
+    S_NOP 0, implicit $vgpr0
+    S_BRANCH %bb.3
+  bb.2:
+    $vgpr0 = IMPLICIT_DEF
+    $vgpr1, dead renamable $vcc = V_ADD_CO_U32_e64 %1, %2, 0, implicit $exec
+    S_NOP 0, implicit $vgpr0, implicit $vgpr1
+    S_BRANCH %bb.3
+  bb.3:
+)MIR",
+      [](MachineFunction &MF, LiveIntervals &LIS) {
+        const auto &R1 =
+            LIS.getInterval(getMI(MF, 2, 0).getOperand(0).getReg());
+        const auto &R2 =
+            LIS.getInterval(getMI(MF, 3, 0).getOperand(0).getReg());
+        MCRegister V1 = getMI(MF, 1, 2).getOperand(0).getReg().asMCReg();
+
+        ASSERT_FALSE(checkRegUnitInterference(
+            LIS, *MF.getSubtarget().getRegisterInfo(), R1, V1));
+        ASSERT_FALSE(checkRegUnitInterference(
+            LIS, *MF.getSubtarget().getRegisterInfo(), R2, V1));
+      });
+}
+
 int main(int argc, char **argv) {
   ::testing::InitGoogleTest(&argc, argv);
   initLLVM();