Index: llvm/lib/CodeGen/GlobalISel/InstructionSelect.cpp
===================================================================
--- llvm/lib/CodeGen/GlobalISel/InstructionSelect.cpp
+++ llvm/lib/CodeGen/GlobalISel/InstructionSelect.cpp
@@ -71,9 +71,10 @@
 
 void InstructionSelect::getAnalysisUsage(AnalysisUsage &AU) const {
   AU.addRequired<TargetPassConfig>();
+  AU.addRequired<GISelKnownBitsAnalysis>();
+  AU.addPreserved<GISelKnownBitsAnalysis>();
+
   if (OptLevel != CodeGenOpt::None) {
-    AU.addRequired<GISelKnownBitsAnalysis>();
-    AU.addPreserved<GISelKnownBitsAnalysis>();
     AU.addRequired<ProfileSummaryInfoWrapperPass>();
     LazyBlockFrequencyInfoPass::getLazyBFIAnalysisUsage(AU);
   }
@@ -97,9 +98,8 @@
   OptLevel = MF.getFunction().hasOptNone() ? CodeGenOpt::None
                                            : MF.getTarget().getOptLevel();
 
-  GISelKnownBits *KB = nullptr;
+  GISelKnownBits *KB = &getAnalysis<GISelKnownBitsAnalysis>().get(MF);
   if (OptLevel != CodeGenOpt::None) {
-    KB = &getAnalysis<GISelKnownBitsAnalysis>().get(MF);
     PSI = &getAnalysis<ProfileSummaryInfoWrapperPass>().getPSI();
     if (PSI && PSI->hasProfileSummary())
       BFI = &getAnalysis<LazyBlockFrequencyInfoPass>().getBFI();
Index: llvm/test/CodeGen/AArch64/GlobalISel/gisel-commandline-option.ll
===================================================================
--- llvm/test/CodeGen/AArch64/GlobalISel/gisel-commandline-option.ll
+++ llvm/test/CodeGen/AArch64/GlobalISel/gisel-commandline-option.ll
@@ -71,7 +71,7 @@
 ; VERIFY-NEXT:   Verify generated machine code
 ; ENABLED-NEXT:  Localizer
 ; VERIFY-O0-NEXT:   Verify generated machine code
-; ENABLED-O1-NEXT: Analysis for ComputingKnownBits
+; ENABLED-NEXT: Analysis for ComputingKnownBits
 ; ENABLED-O1-NEXT: Lazy Branch Probability Analysis
 ; ENABLED-O1-NEXT: Lazy Block Frequency Analysis
 ; ENABLED-NEXT:  InstructionSelect
Index: llvm/test/CodeGen/AMDGPU/GlobalISel/crash-stack-address-O0.ll
===================================================================
--- /dev/null
+++ llvm/test/CodeGen/AMDGPU/GlobalISel/crash-stack-address-O0.ll
@@ -0,0 +1,25 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -global-isel -O0 -mtriple=amdgcn-amd-amdhsa -mcpu=fiji -o - %s | FileCheck %s
+
+; Make sure there's no crash at -O0 when matching MUBUF addressing
+; modes for the stack.
+
+define amdgpu_kernel void @stack_write_fi() {
+; CHECK-LABEL: stack_write_fi:
+; CHECK:       ; %bb.0: ; %entry
+; CHECK-NEXT:    s_add_u32 s0, s0, s7
+; CHECK-NEXT:    s_addc_u32 s1, s1, 0
+; CHECK-NEXT:    s_mov_b32 s5, 0
+; CHECK-NEXT:    s_mov_b32 s4, 0
+; CHECK-NEXT:    v_mov_b32_e32 v0, s5
+; CHECK-NEXT:    buffer_store_dword v0, off, s[0:3], 0 offset:4
+; CHECK-NEXT:    s_waitcnt vmcnt(0)
+; CHECK-NEXT:    v_mov_b32_e32 v0, s4
+; CHECK-NEXT:    buffer_store_dword v0, off, s[0:3], 0 offset:8
+; CHECK-NEXT:    s_waitcnt vmcnt(0)
+; CHECK-NEXT:    s_endpgm
+entry:
+  %alloca = alloca i64, align 4, addrspace(5)
+  store volatile i64 0, i64 addrspace(5)* %alloca, align 4
+  ret void
+}
Index: llvm/test/CodeGen/AMDGPU/GlobalISel/inst-select-load-private.mir
===================================================================
--- llvm/test/CodeGen/AMDGPU/GlobalISel/inst-select-load-private.mir
+++ llvm/test/CodeGen/AMDGPU/GlobalISel/inst-select-load-private.mir
@@ -1,5 +1,6 @@
 # NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
 # RUN: llc -march=amdgcn -mcpu=tahiti -run-pass=instruction-select -verify-machineinstrs  -global-isel-abort=0 -o - %s | FileCheck -check-prefix=GFX6 %s
+# RUN: llc -O0 -march=amdgcn -mcpu=tahiti -run-pass=instruction-select -verify-machineinstrs  -global-isel-abort=0 -o - %s | FileCheck -check-prefix=GFX6 %s
 # RUN: llc -march=amdgcn -mcpu=gfx900 -run-pass=instruction-select -verify-machineinstrs -global-isel-abort=0 -o - %s | FileCheck -check-prefix=GFX9 %s
 # RUN: llc -march=amdgcn -mcpu=gfx1010 -run-pass=instruction-select -verify-machineinstrs -global-isel-abort=0 -o - %s | FileCheck -check-prefix=GFX9 %s
 
Index: llvm/test/CodeGen/AMDGPU/GlobalISel/inst-select-store-private.mir
===================================================================
--- llvm/test/CodeGen/AMDGPU/GlobalISel/inst-select-store-private.mir
+++ llvm/test/CodeGen/AMDGPU/GlobalISel/inst-select-store-private.mir
@@ -1,5 +1,6 @@
 # NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
 # RUN: llc -march=amdgcn -mcpu=tahiti -run-pass=instruction-select -verify-machineinstrs  -global-isel-abort=0 -o - %s | FileCheck -check-prefix=GFX6 %s
+# RUN: llc -O0 -march=amdgcn -mcpu=tahiti -run-pass=instruction-select -verify-machineinstrs  -global-isel-abort=0 -o - %s | FileCheck -check-prefix=GFX6 %s
 # RUN: llc -march=amdgcn -mcpu=gfx900 -run-pass=instruction-select -verify-machineinstrs -global-isel-abort=0 -o - %s | FileCheck -check-prefix=GFX9 %s
 # XUN: llc -march=amdgcn -mcpu=gfx1010 -run-pass=instruction-select -verify-machineinstrs -global-isel-abort=0 -o - %s | FileCheck -check-prefix=GFX9 %s