diff --git a/llvm/test/CodeGen/AMDGPU/GlobalISel/fdiv.f16.ll b/llvm/test/CodeGen/AMDGPU/GlobalISel/fdiv.f16.ll
--- a/llvm/test/CodeGen/AMDGPU/GlobalISel/fdiv.f16.ll
+++ b/llvm/test/CodeGen/AMDGPU/GlobalISel/fdiv.f16.ll
@@ -3,11 +3,11 @@
 ; RUN: llc -global-isel -march=amdgcn -mcpu=tahiti -denormal-fp-math=ieee -verify-machineinstrs < %s | FileCheck -check-prefixes=GFX6,GFX6-IEEE %s
 ; RUN: llc -global-isel -march=amdgcn -mcpu=tahiti -denormal-fp-math=preserve-sign -verify-machineinstrs < %s | FileCheck -check-prefixes=GFX6,GFX6-FLUSH %s
 
-; RUN: llc -global-isel -march=amdgcn -mcpu=fiji -denormal-fp-math=ieee -verify-machineinstrs < %s | FileCheck -check-prefixes=GFX89,GFX8,GFX8-IEEE %s
-; RUN: llc -global-isel -march=amdgcn -mcpu=fiji -denormal-fp-math=preserve-sign -verify-machineinstrs < %s | FileCheck -check-prefixes=GFX89,GFX8,GFX8-FLUSH %s
+; RUN: llc -global-isel -march=amdgcn -mcpu=fiji -denormal-fp-math=ieee -verify-machineinstrs < %s | FileCheck -check-prefixes=GFX89,GFX8 %s
+; RUN: llc -global-isel -march=amdgcn -mcpu=fiji -denormal-fp-math=preserve-sign -verify-machineinstrs < %s | FileCheck -check-prefixes=GFX89,GFX8 %s
 
-; RUN: llc -global-isel -march=amdgcn -mcpu=gfx900 -denormal-fp-math=ieee -verify-machineinstrs < %s | FileCheck -check-prefixes=GFX89,GFX9,GFX9-IEEE %s
-; RUN: llc -global-isel -march=amdgcn -mcpu=gfx900 -denormal-fp-math=preserve-sign -verify-machineinstrs < %s | FileCheck -check-prefixes=GFX89,GFX9,GFX9-FLUSH %s
+; RUN: llc -global-isel -march=amdgcn -mcpu=gfx900 -denormal-fp-math=ieee -verify-machineinstrs < %s | FileCheck -check-prefixes=GFX89,GFX9 %s
+; RUN: llc -global-isel -march=amdgcn -mcpu=gfx900 -denormal-fp-math=preserve-sign -verify-machineinstrs < %s | FileCheck -check-prefixes=GFX89,GFX9 %s
 
 define half @v_fdiv_f16(half %a, half %b) {
 ; GFX6-IEEE-LABEL: v_fdiv_f16:
diff --git a/llvm/test/CodeGen/AMDGPU/GlobalISel/fdiv.f32.ll b/llvm/test/CodeGen/AMDGPU/GlobalISel/fdiv.f32.ll
--- a/llvm/test/CodeGen/AMDGPU/GlobalISel/fdiv.f32.ll
+++ b/llvm/test/CodeGen/AMDGPU/GlobalISel/fdiv.f32.ll
@@ -1,12 +1,12 @@
 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
-; RUN: llc -global-isel -march=amdgcn -mcpu=tahiti -denormal-fp-math=ieee -verify-machineinstrs < %s | FileCheck -check-prefixes=GCN,GCN-IEEE,GFX6,GFX6-IEEE %s
-; RUN: llc -global-isel -march=amdgcn -mcpu=tahiti -denormal-fp-math=preserve-sign -verify-machineinstrs < %s | FileCheck -check-prefixes=GCN,GCN-FLUSH,GFX6,GFX6-FLUSH %s
+; RUN: llc -global-isel -march=amdgcn -mcpu=tahiti -denormal-fp-math=ieee -verify-machineinstrs < %s | FileCheck -check-prefixes=GCN,GCN-IEEE,GFX6-IEEE %s
+; RUN: llc -global-isel -march=amdgcn -mcpu=tahiti -denormal-fp-math=preserve-sign -verify-machineinstrs < %s | FileCheck -check-prefixes=GCN,GCN-FLUSH,GFX6-FLUSH %s
 
-; RUN: llc -global-isel -march=amdgcn -mcpu=fiji -denormal-fp-math=ieee -verify-machineinstrs < %s | FileCheck -check-prefixes=GCN,GCN-IEEE,GFX89-IEEE,GFX89,GFX8,GFX8-IEEE %s
-; RUN: llc -global-isel -march=amdgcn -mcpu=fiji -denormal-fp-math=preserve-sign -verify-machineinstrs < %s | FileCheck -check-prefixes=GCN,GCN-FLUSH,GFX89,GFX89-FLUSH,GFX8,GFX8-FLUSH %s
+; RUN: llc -global-isel -march=amdgcn -mcpu=fiji -denormal-fp-math=ieee -verify-machineinstrs < %s | FileCheck -check-prefixes=GCN,GCN-IEEE,GFX89-IEEE %s
+; RUN: llc -global-isel -march=amdgcn -mcpu=fiji -denormal-fp-math=preserve-sign -verify-machineinstrs < %s | FileCheck -check-prefixes=GCN,GCN-FLUSH,GFX89-FLUSH %s
 
-; RUN: llc -global-isel -march=amdgcn -mcpu=gfx900 -denormal-fp-math=ieee -verify-machineinstrs < %s | FileCheck -check-prefixes=GCN,GCN-IEEE,GFX89,GFX89-IEEE,GFX9,GFX9-IEEE %s
-; RUN: llc -global-isel -march=amdgcn -mcpu=gfx900 -denormal-fp-math=preserve-sign -verify-machineinstrs < %s | FileCheck -check-prefixes=GCN,GCN-FLUSH,GFX89,GFX89-FLUSH,GFX9,GFX9-FLUSH %s
+; RUN: llc -global-isel -march=amdgcn -mcpu=gfx900 -denormal-fp-math=ieee -verify-machineinstrs < %s | FileCheck -check-prefixes=GCN,GCN-IEEE,GFX89-IEEE %s
+; RUN: llc -global-isel -march=amdgcn -mcpu=gfx900 -denormal-fp-math=preserve-sign -verify-machineinstrs < %s | FileCheck -check-prefixes=GCN,GCN-FLUSH,GFX89-FLUSH %s
 
 define float @v_fdiv_f32(float %a, float %b) {
 ; GFX6-IEEE-LABEL: v_fdiv_f32:
diff --git a/llvm/test/CodeGen/AMDGPU/lit.local.cfg b/llvm/test/CodeGen/AMDGPU/lit.local.cfg
--- a/llvm/test/CodeGen/AMDGPU/lit.local.cfg
+++ b/llvm/test/CodeGen/AMDGPU/lit.local.cfg
@@ -1,2 +1,12 @@
+from lit.llvm.subst import ToolSubst
+
 if not 'AMDGPU' in config.root.targets:
     config.unsupported = True
+
+fc = ToolSubst('FileCheck', unresolved='fatal')
+# Insert this first. Then, we'll first update the blank FileCheck command; then,
+# the default substitution of FileCheck will replace it to its full path.
+config.substitutions.insert(0, (fc.regex,
+    'FileCheck --allow-unused-prefixes=false'))
+
+
diff --git a/llvm/test/CodeGen/AMDGPU/non-entry-alloca.ll b/llvm/test/CodeGen/AMDGPU/non-entry-alloca.ll
--- a/llvm/test/CodeGen/AMDGPU/non-entry-alloca.ll
+++ b/llvm/test/CodeGen/AMDGPU/non-entry-alloca.ll
@@ -1,8 +1,8 @@
 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
-; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx900 -verify-machineinstrs < %s | FileCheck -check-prefixes=GCN,DEFAULTSIZE,MUBUF %s
-; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx900 -verify-machineinstrs -amdgpu-assume-dynamic-stack-object-size=1024 < %s | FileCheck -check-prefixes=GCN,ASSUME1024,MUBUF %s
-; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx900 -verify-machineinstrs -amdgpu-enable-flat-scratch < %s | FileCheck -check-prefixes=GCN,DEFAULTSIZE,FLATSCR %s
-; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx900 -verify-machineinstrs -amdgpu-enable-flat-scratch -amdgpu-assume-dynamic-stack-object-size=1024 < %s | FileCheck -check-prefixes=GCN,ASSUME1024,FLATSCR %s
+; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx900 -verify-machineinstrs < %s | FileCheck -check-prefixes=DEFAULTSIZE,MUBUF %s
+; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx900 -verify-machineinstrs -amdgpu-assume-dynamic-stack-object-size=1024 < %s | FileCheck -check-prefixes=ASSUME1024,MUBUF %s
+; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx900 -verify-machineinstrs -amdgpu-enable-flat-scratch < %s | FileCheck -check-prefixes=DEFAULTSIZE,FLATSCR %s
+; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx900 -verify-machineinstrs -amdgpu-enable-flat-scratch -amdgpu-assume-dynamic-stack-object-size=1024 < %s | FileCheck -check-prefixes=ASSUME1024,FLATSCR %s
 
 ; FIXME: Generated test checks do not check metadata at the end of the
 ; function, so this also includes manually added checks.