Index: llvm/lib/CodeGen/LocalStackSlotAllocation.cpp
===================================================================
--- llvm/lib/CodeGen/LocalStackSlotAllocation.cpp
+++ llvm/lib/CodeGen/LocalStackSlotAllocation.cpp
@@ -351,6 +351,14 @@
     assert(MFI.isObjectPreAllocated(FrameIdx) &&
            "Only pre-allocated locals expected!");
 
+    // We need to keep the references to the stack protector slot through frame
+    // index operands so that it gets resolved by PEI rather than this pass.
+    // This avoids accesses to the stack protector though virtual base
+    // registers, and forces PEI to address it using fp/sp/bp.
+    if (MFI.hasStackProtectorIndex() &&
+        FrameIdx == MFI.getStackProtectorIndex())
+      continue;
+
     LLVM_DEBUG(dbgs() << "Considering: " << MI);
 
     unsigned idx = 0;
Index: llvm/test/CodeGen/AArch64/stack-guard-reassign.ll
===================================================================
--- llvm/test/CodeGen/AArch64/stack-guard-reassign.ll
+++ llvm/test/CodeGen/AArch64/stack-guard-reassign.ll
@@ -3,7 +3,6 @@
 ; Verify that the offset assigned to the stack protector is at the top of the
 ; frame, covering the locals.
 ; CHECK-LABEL: fn:
-; CHECK:      sub x8, x29, #24
-; CHECK-NEXT: adrp x9, __stack_chk_guard
-; CHECK-NEXT: ldr x9, [x9, :lo12:__stack_chk_guard]
-; CHECK-NEXT: str x9, [x8]
+; CHECK:      adrp x8, __stack_chk_guard
+; CHECK-NEXT: ldr x8, [x8, :lo12:__stack_chk_guard]
+; CHECK-NEXT: stur x8, [x29, #-24]
Index: llvm/test/CodeGen/ARM/stack-guard-reassign.ll
===================================================================
--- llvm/test/CodeGen/ARM/stack-guard-reassign.ll
+++ llvm/test/CodeGen/ARM/stack-guard-reassign.ll
@@ -5,10 +5,9 @@
 ; CHECK-LABEL: fn:
 ; CHECK:      sub sp, sp, #32
 ; CHECK-NEXT: sub sp, sp, #65536
+; CHECK-NEXT: ldr r1, .LCPI0_0
+; CHECK-NEXT: ldr r2, [r1]
 ; CHECK-NEXT: add lr, sp, #65536
-; CHECK-NEXT: add r1, lr, #28
-; CHECK-NEXT: ldr r2, .LCPI0_0
-; CHECK-NEXT: ldr r3, [r2]
-; CHECK-NEXT: str r3, [r1]
+; CHECK-NEXT: str r2, [lr, #28]
 ; CHECK: .LCPI0_0:
 ; CHECK-NEXT: .long __stack_chk_guard
Index: llvm/test/CodeGen/PowerPC/stack-guard-reassign.ll
===================================================================
--- llvm/test/CodeGen/PowerPC/stack-guard-reassign.ll
+++ llvm/test/CodeGen/PowerPC/stack-guard-reassign.ll
@@ -9,9 +9,8 @@
 ; CHECK-NEXT: ori 0, 0, 65488
 ; CHECK-NEXT: stwux 1, 1, 0
 ; CHECK-NEXT: subf 0, 0, 1
-; CHECK-NEXT: lis 4, 1
-; CHECK-NEXT: ori 4, 4, 44
-; CHECK-NEXT: add 4, 1, 4
-; CHECK-NEXT: lis 5, __stack_chk_guard@ha
-; CHECK-NEXT: lwz 6, __stack_chk_guard@l(5)
-; CHECK-NEXT: stw 6, 0(4)
+; CHECK-NEXT: lis 4, __stack_chk_guard@ha
+; CHECK-NEXT: lwz 5, __stack_chk_guard@l(4)
+; CHECK-NEXT: lis 6, 1
+; CHECK-NEXT: ori 6, 6, 44
+; CHECK-NEXT: stwx 5, 1, 6
Index: llvm/test/CodeGen/Thumb/stack_guard_remat.ll
===================================================================
--- llvm/test/CodeGen/Thumb/stack_guard_remat.ll
+++ llvm/test/CodeGen/Thumb/stack_guard_remat.ll
@@ -2,25 +2,40 @@
 ; RUN: llc < %s -mtriple=thumb-apple-darwin -relocation-model=static -no-integrated-as | FileCheck %s -check-prefix=NO-PIC  -check-prefix=STATIC
 ; RUN: llc < %s -mtriple=thumb-apple-darwin -relocation-model=dynamic-no-pic -no-integrated-as | FileCheck %s  -check-prefix=NO-PIC -check-prefix=DYNAMIC-NO-PIC
 
-;PIC:   foo2
-;PIC:   ldr [[R0:r[0-9]+]], [[LABEL0:LCPI[0-9_]+]]
-;PIC: [[LABEL1:LPC[0-9_]+]]:
-;PIC:   add [[R0]], pc
-;PIC:   ldr [[R1:r[0-9]+]], {{\[}}[[R0]]{{\]}}
-;PIC:   ldr [[R1:r[0-9]+]], {{\[}}[[R1]]{{\]}}
-
-;PIC:      [[LABEL0]]:
+;PIC:        foo2
+;PIC:        ldr [[SAVED_GUARD:r[0-9]+]], [[GUARD_STACK_OFFSET:LCPI[0-9_]+]]
+;PIC-NEXT:   add [[SAVED_GUARD]], sp
+;PIC-NEXT:   ldr [[SAVED_GUARD]], {{\[}}[[SAVED_GUARD]]{{\]}}
+;PIC-NEXT:   ldr [[ORIGINAL_GUARD:r[0-9]+]], [[ORIGINAL_GUARD_LABEL:LCPI[0-9_]+]]
+;PIC-NEXT: [[LABEL1:LPC[0-9_]+]]:
+;PIC-NEXT:   add [[ORIGINAL_GUARD]], pc
+;PIC-NEXT:   ldr [[ORIGINAL_GUARD]], {{\[}}[[ORIGINAL_GUARD]]{{\]}}
+;PIC-NEXT:   ldr [[ORIGINAL_GUARD]], {{\[}}[[ORIGINAL_GUARD]]{{\]}}
+;PIC-NEXT:   subs {{r[0-9]+}}, [[ORIGINAL_GUARD]], [[SAVED_GUARD]]
+
+;PIC:      [[GUARD_STACK_OFFSET]]:
+;PIC-NEXT:   .long 1028
+;PIC:      [[ORIGINAL_GUARD_LABEL]]:
 ;PIC-NEXT:   .long L___stack_chk_guard$non_lazy_ptr-([[LABEL1]]+4)
 
 ;NO-PIC:   foo2
-;NO-PIC:   ldr [[R0:r[0-9]+]], [[LABEL0:LCPI[0-9_]+]]
+;NO-PIC:                ldr [[SAVED_GUARD:r[0-9]+]], [[GUARD_STACK_OFFSET:LCPI[0-9_]+]]
+;NO-PIC-NEXT:           add [[SAVED_GUARD]], sp
+;NO-PIC-NEXT:           ldr [[SAVED_GUARD]], {{\[}}[[SAVED_GUARD]]{{\]}}
+;NO-PIC-NEXT:           ldr [[ORIGINAL_GUARD:r[0-9]+]], [[ORIGINAL_GUARD_LABEL:LCPI[0-9_]+]]
 ;NO-PIC-NOT: LPC
-;NO-PIC:   ldr {{r[0-9]+}}, {{\[}}[[R0]]{{\]}}
+;NO-PIC-NEXT:           ldr [[ORIGINAL_GUARD]], {{\[}}[[ORIGINAL_GUARD]]{{\]}}
+;DYNAMIC-NO-PIC-NEXT:   ldr [[ORIGINAL_GUARD]], {{\[}}[[ORIGINAL_GUARD]]{{\]}}
+;NO-PIC-NEXT:           subs {{r[0-9]+}}, [[ORIGINAL_GUARD]], [[SAVED_GUARD]]
 
-;STATIC:      [[LABEL0]]:
+;STATIC:      [[GUARD_STACK_OFFSET]]:
+;STATIC-NEXT:   .long 1028
+;STATIC:      [[ORIGINAL_GUARD_LABEL]]:
 ;STATIC-NEXT:   .long ___stack_chk_guard
 
-;DYNAMIC-NO-PIC:      [[LABEL0]]:
+;DYNAMIC-NO-PIC:      [[GUARD_STACK_OFFSET]]:
+;DYNAMIC-NO-PIC-NEXT:   .long 1028
+;DYNAMIC-NO-PIC:      [[ORIGINAL_GUARD_LABEL]]:
 ;DYNAMIC-NO-PIC-NEXT:   .long L___stack_chk_guard$non_lazy_ptr
 
 ; Function Attrs: nounwind ssp