diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index 43b5a20006ba7..92d1bd1bb0252 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -3851,13 +3851,10 @@ X86TargetLowering::LowerMemArgument(SDValue Chain, CallingConv::ID CallConv,
 
   EVT ArgVT = Ins[i].ArgVT;
 
-  // If this is a vector that has been split into multiple parts, and the
-  // scalar size of the parts don't match the vector element size, then we can't
-  // elide the copy. The parts will have padding between them instead of being
-  // packed like a vector.
-  bool ScalarizedAndExtendedVector =
-      ArgVT.isVector() && !VA.getLocVT().isVector() &&
-      VA.getLocVT().getSizeInBits() != ArgVT.getScalarSizeInBits();
+  // If this is a vector that has been split into multiple parts, don't elide
+  // the copy. The layout on the stack may not match the packed in-memory
+  // layout.
+  bool ScalarizedVector = ArgVT.isVector() && !VA.getLocVT().isVector();
 
   // This is an argument in memory. We might be able to perform copy elision.
   // If the argument is passed directly in memory without any extension, then we
@@ -3865,7 +3862,7 @@ X86TargetLowering::LowerMemArgument(SDValue Chain, CallingConv::ID CallConv,
   // indirectly by pointer.
   if (Flags.isCopyElisionCandidate() &&
       VA.getLocInfo() != CCValAssign::Indirect && !ExtendedInMem &&
-      !ScalarizedAndExtendedVector) {
+      !ScalarizedVector) {
     SDValue PartAddr;
     if (Ins[i].PartOffset == 0) {
       // If this is a one-part value or the first part of a multi-part value,
diff --git a/llvm/test/CodeGen/X86/pr63475.ll b/llvm/test/CodeGen/X86/pr63475.ll
index d4b7a7cacefda..0052688b5aa13 100644
--- a/llvm/test/CodeGen/X86/pr63475.ll
+++ b/llvm/test/CodeGen/X86/pr63475.ll
@@ -27,7 +27,8 @@ define void @caller() nounwind {
   ret void
 }
 
-; FIXME: This is a miscompile.
+; Make sure the stack offsets are correct. The distance between them should
+; be 8, not 4.
 define void @callee(ptr %p0, ptr %p1, ptr %p2, ptr %p3, ptr %p4, ptr %p5, <7 x i32> %arg) nounwind {
 ; CHECK-LABEL: callee:
 ; CHECK:       # %bb.0: # %start
@@ -37,28 +38,41 @@ define void @callee(ptr %p0, ptr %p1, ptr %p2, ptr %p3, ptr %p4, ptr %p5, <7 x i
 ; CHECK-NEXT:    pushq %r13
 ; CHECK-NEXT:    pushq %r12
 ; CHECK-NEXT:    pushq %rbx
-; CHECK-NEXT:    pushq %rax
-; CHECK-NEXT:    movl 112(%rsp), %ebx
-; CHECK-NEXT:    movl 104(%rsp), %ebp
-; CHECK-NEXT:    movl 96(%rsp), %r14d
-; CHECK-NEXT:    movl 76(%rsp), %r15d
-; CHECK-NEXT:    movl 72(%rsp), %r12d
-; CHECK-NEXT:    movl 64(%rsp), %edi
-; CHECK-NEXT:    movl 68(%rsp), %r13d
-; CHECK-NEXT:    callq use@PLT
-; CHECK-NEXT:    movl %r13d, %edi
-; CHECK-NEXT:    callq use@PLT
-; CHECK-NEXT:    movl %r12d, %edi
+; CHECK-NEXT:    subq $40, %rsp
+; CHECK-NEXT:    movl 120(%rsp), %ebx
+; CHECK-NEXT:    movd %ebx, %xmm0
+; CHECK-NEXT:    movl 112(%rsp), %ebp
+; CHECK-NEXT:    movd %ebp, %xmm1
+; CHECK-NEXT:    punpckldq {{.*#+}} xmm1 = xmm1[0],xmm0[0],xmm1[1],xmm0[1]
+; CHECK-NEXT:    movl 104(%rsp), %r15d
+; CHECK-NEXT:    movd %r15d, %xmm0
+; CHECK-NEXT:    movl 96(%rsp), %edi
+; CHECK-NEXT:    movd %edi, %xmm2
+; CHECK-NEXT:    punpckldq {{.*#+}} xmm2 = xmm2[0],xmm0[0],xmm2[1],xmm0[1]
+; CHECK-NEXT:    punpcklqdq {{.*#+}} xmm2 = xmm2[0],xmm1[0]
+; CHECK-NEXT:    movl 136(%rsp), %r14d
+; CHECK-NEXT:    movd %r14d, %xmm0
+; CHECK-NEXT:    movl 128(%rsp), %r12d
+; CHECK-NEXT:    movd %r12d, %xmm1
+; CHECK-NEXT:    punpckldq {{.*#+}} xmm1 = xmm1[0],xmm0[0],xmm1[1],xmm0[1]
+; CHECK-NEXT:    movl 144(%rsp), %r13d
+; CHECK-NEXT:    movl %r13d, 36(%rsp)
+; CHECK-NEXT:    movq %xmm1, 28(%rsp)
+; CHECK-NEXT:    movdqu %xmm2, 12(%rsp)
 ; CHECK-NEXT:    callq use@PLT
 ; CHECK-NEXT:    movl %r15d, %edi
 ; CHECK-NEXT:    callq use@PLT
-; CHECK-NEXT:    movl %r14d, %edi
-; CHECK-NEXT:    callq use@PLT
 ; CHECK-NEXT:    movl %ebp, %edi
 ; CHECK-NEXT:    callq use@PLT
 ; CHECK-NEXT:    movl %ebx, %edi
 ; CHECK-NEXT:    callq use@PLT
-; CHECK-NEXT:    addq $8, %rsp
+; CHECK-NEXT:    movl %r12d, %edi
+; CHECK-NEXT:    callq use@PLT
+; CHECK-NEXT:    movl %r14d, %edi
+; CHECK-NEXT:    callq use@PLT
+; CHECK-NEXT:    movl %r13d, %edi
+; CHECK-NEXT:    callq use@PLT
+; CHECK-NEXT:    addq $40, %rsp
 ; CHECK-NEXT:    popq %rbx
 ; CHECK-NEXT:    popq %r12
 ; CHECK-NEXT:    popq %r13