Index: llvm/include/llvm/Support/FileCheck.h
===================================================================
--- llvm/include/llvm/Support/FileCheck.h
+++ llvm/include/llvm/Support/FileCheck.h
@@ -30,6 +30,7 @@
   std::vector<std::string> GlobalDefines;
   bool AllowEmptyInput = false;
   bool MatchFullLines = false;
+  bool IgnoreCase = false;
   bool EnableVarScope = false;
   bool AllowDeprecatedDagOverlap = false;
   bool Verbose = false;
Index: llvm/lib/Support/FileCheck.cpp
===================================================================
--- llvm/lib/Support/FileCheck.cpp
+++ llvm/lib/Support/FileCheck.cpp
@@ -320,6 +320,7 @@
                                     SourceMgr &SM,
                                     const FileCheckRequest &Req) {
   bool MatchFullLinesHere = Req.MatchFullLines && CheckTy != Check::CheckNot;
+  IgnoreCase = Req.IgnoreCase;
 
   PatternLoc = SMLoc::getFromPointer(PatternStr.data());
 
@@ -619,7 +620,8 @@
   // If this is a fixed string pattern, just match it now.
   if (!FixedStr.empty()) {
     MatchLen = FixedStr.size();
-    size_t Pos = Buffer.find(FixedStr);
+    size_t Pos = IgnoreCase ? Buffer.find_lower(FixedStr)
+                            : Buffer.find(FixedStr);
     if (Pos == StringRef::npos)
       return make_error<FileCheckNotFoundError>();
     return Pos;
@@ -657,7 +659,10 @@
   }
 
   SmallVector<StringRef, 4> MatchInfo;
-  if (!Regex(RegExToMatch, Regex::Newline).match(Buffer, &MatchInfo))
+  unsigned int Flags = Regex::Newline;
+  if (IgnoreCase)
+    Flags |= Regex::IgnoreCase;
+  if (!Regex(RegExToMatch, Flags).match(Buffer, &MatchInfo))
     return make_error<FileCheckNotFoundError>();
 
   // Successful regex match.
Index: llvm/lib/Support/FileCheckImpl.h
===================================================================
--- llvm/lib/Support/FileCheckImpl.h
+++ llvm/lib/Support/FileCheckImpl.h
@@ -428,10 +428,13 @@
   /// line to the one with this CHECK.
   Optional<size_t> LineNumber;
 
+  /// Ignore case while matching if set to true.
+  bool IgnoreCase;
+
 public:
   FileCheckPattern(Check::FileCheckType Ty, FileCheckPatternContext *Context,
                    Optional<size_t> Line = None)
-      : Context(Context), CheckTy(Ty), LineNumber(Line) {}
+      : Context(Context), CheckTy(Ty), LineNumber(Line), IgnoreCase(false) {}
 
   /// \returns the location in source code.
   SMLoc getLoc() const { return PatternLoc; }
Index: llvm/test/tools/llvm-objcopy/ELF/basic-binary-copy.test
===================================================================
--- llvm/test/tools/llvm-objcopy/ELF/basic-binary-copy.test
+++ llvm/test/tools/llvm-objcopy/ELF/basic-binary-copy.test
@@ -1,6 +1,6 @@
 # RUN: yaml2obj %s -o %t
 # RUN: llvm-objcopy -O binary %t %t2
-# RUN: od -t x2 -v %t2 | FileCheck %s
+# RUN: od -t x2 -v %t2 | FileCheck %s --ignore-case
 # RUN: wc -c < %t2 | FileCheck %s --check-prefix=SIZE
 
 !ELF
Index: llvm/test/tools/llvm-objcopy/ELF/binary-no-paddr.test
===================================================================
--- llvm/test/tools/llvm-objcopy/ELF/binary-no-paddr.test
+++ llvm/test/tools/llvm-objcopy/ELF/binary-no-paddr.test
@@ -1,6 +1,6 @@
 # RUN: yaml2obj %s -o %t
 # RUN: llvm-objcopy -O binary %t %t2
-# RUN: od -t x2 -v %t2 | FileCheck %s
+# RUN: od -t x2 -v %t2 | FileCheck %s --ignore-case
 # RUN: wc -c < %t2 | FileCheck %s --check-prefix=SIZE
 
 !ELF
Index: llvm/test/tools/llvm-objcopy/ELF/binary-paddr.test
===================================================================
--- llvm/test/tools/llvm-objcopy/ELF/binary-paddr.test
+++ llvm/test/tools/llvm-objcopy/ELF/binary-paddr.test
@@ -1,6 +1,6 @@
 # RUN: yaml2obj %s -o %t
 # RUN: llvm-objcopy -O binary %t %t2
-# RUN: od -t x2 %t2 | FileCheck %s
+# RUN: od -t x2 %t2 | FileCheck %s --ignore-case
 # RUN: wc -c < %t2 | FileCheck %s --check-prefix=SIZE
 
 !ELF
Index: llvm/test/tools/llvm-objcopy/ELF/binary-segment-layout.test
===================================================================
--- llvm/test/tools/llvm-objcopy/ELF/binary-segment-layout.test
+++ llvm/test/tools/llvm-objcopy/ELF/binary-segment-layout.test
@@ -1,6 +1,6 @@
 # RUN: yaml2obj %s -o %t
 # RUN: llvm-objcopy -O binary %t %t2
-# RUN: od -t x2 %t2 | FileCheck %s
+# RUN: od -t x2 %t2 | FileCheck %s --ignore-case
 # RUN: wc -c < %t2 | FileCheck %s --check-prefix=SIZE
 
 !ELF
Index: llvm/test/tools/llvm-objcopy/ELF/check-addr-offset-align-binary.test
===================================================================
--- llvm/test/tools/llvm-objcopy/ELF/check-addr-offset-align-binary.test
+++ llvm/test/tools/llvm-objcopy/ELF/check-addr-offset-align-binary.test
@@ -1,6 +1,6 @@
 # RUN: yaml2obj %s -o %t
 # RUN: llvm-objcopy -O binary %t %t2
-# RUN: od -t x1 %t2 | FileCheck %s
+# RUN: od -t x1 %t2 | FileCheck %s --ignore-case
 
 !ELF
 FileHeader:
Index: llvm/test/tools/llvm-objcopy/ELF/dump-section.test
===================================================================
--- llvm/test/tools/llvm-objcopy/ELF/dump-section.test
+++ llvm/test/tools/llvm-objcopy/ELF/dump-section.test
@@ -4,8 +4,8 @@
 # RUN: llvm-objcopy --dump-section .text=%t4 %t %t5
 # RUN: llvm-objcopy --dump-section .foo=%t6 %t %t7
 # RUN: not llvm-objcopy --dump-section .bar=%t8 %t %t9 2>&1 | FileCheck %s --check-prefix=NOBITS -DINPUT=%t
-# RUN: od -t x1 %t2 | FileCheck %s
-# RUN: od -t x1 %t6 | FileCheck %s --check-prefix=NON-ALLOC
+# RUN: od -t x1 %t2 | FileCheck %s --ignore-case
+# RUN: od -t x1 %t6 | FileCheck %s --ignore-case --check-prefix=NON-ALLOC
 # RUN: wc -c %t2 | FileCheck %s --check-prefix=SIZE
 # RUN: diff %t2 %t3
 # RUN: diff %t4 %t3
Index: llvm/test/tools/llvm-objcopy/ELF/preserve-segment-contents.test
===================================================================
--- llvm/test/tools/llvm-objcopy/ELF/preserve-segment-contents.test
+++ llvm/test/tools/llvm-objcopy/ELF/preserve-segment-contents.test
@@ -13,13 +13,13 @@
 # RUN: llvm-objcopy %t.base %t.stripped --regex -R blob.*
 # Show that the removal leaves the bytes as zeroes, as desired, for all our
 # test cases.
-# RUN: od -t x1 -j 0x2000 -N 24 %t.stripped | FileCheck %s --check-prefix=CHECK1 -DPATTERN="00 00 00 00"
-# RUN: od -t x1 -j 0x2100 -N 12 %t.stripped | FileCheck %s --check-prefix=CHECK2 -DPATTERN="00 00 00 00"
-# RUN: od -t x1 -j 0x2200 -N 4  %t.stripped | FileCheck %s --check-prefix=CHECK3 -DPATTERN="00 00 00 00"
-# RUN: od -t x1 -j 0x2300 -N 12 %t.stripped | FileCheck %s --check-prefix=CHECK4 -DPATTERN="00 00 00 00"
-# RUN: od -t x1 -j 0x3000 -N 68 %t.stripped | FileCheck %s --check-prefix=CHECK5 -DPATTERN="00 00 00 00"
-# RUN: od -t x1 -j 0x4000 -N 60 %t.stripped | FileCheck %s --check-prefix=CHECK6 -DPATTERN="00 00 00 00"
-# RUN: od -t x1 -j 0x5000 -N 60 %t.stripped | FileCheck %s --check-prefix=CHECK7 -DPATTERN="00 00 00 00"
+# RUN: od -t x1 -j 0x2000 -N 24 %t.stripped | FileCheck %s --ignore-case --check-prefix=CHECK1 -DPATTERN="00 00 00 00"
+# RUN: od -t x1 -j 0x2100 -N 12 %t.stripped | FileCheck %s --ignore-case --check-prefix=CHECK2 -DPATTERN="00 00 00 00"
+# RUN: od -t x1 -j 0x2200 -N 4  %t.stripped | FileCheck %s --ignore-case --check-prefix=CHECK3 -DPATTERN="00 00 00 00"
+# RUN: od -t x1 -j 0x2300 -N 12 %t.stripped | FileCheck %s --ignore-case --check-prefix=CHECK4 -DPATTERN="00 00 00 00"
+# RUN: od -t x1 -j 0x3000 -N 68 %t.stripped | FileCheck %s --ignore-case --check-prefix=CHECK5 -DPATTERN="00 00 00 00"
+# RUN: od -t x1 -j 0x4000 -N 60 %t.stripped | FileCheck %s --ignore-case --check-prefix=CHECK6 -DPATTERN="00 00 00 00"
+# RUN: od -t x1 -j 0x5000 -N 60 %t.stripped | FileCheck %s --ignore-case --check-prefix=CHECK7 -DPATTERN="00 00 00 00"
 
 # RUN: cp %t.stripped %t.in
 # RUN: echo "with open('%/t.in', 'rb+') as input:"                                 > %t.py
@@ -32,13 +32,13 @@
 # RUN: echo "    input.write(bytearray.fromhex('DEADBEEF'))"                      >> %t.py
 # RUN: %python %t.py
 # RUN: llvm-objcopy %t.in %t.out
-# RUN: od -t x1 -j 0x2000 -N 24 %t.out | FileCheck %s --check-prefix=CHECK1 -DPATTERN="de ad be ef"
-# RUN: od -t x1 -j 0x2100 -N 12 %t.out | FileCheck %s --check-prefix=CHECK2 -DPATTERN="de ad be ef"
-# RUN: od -t x1 -j 0x2200 -N 4  %t.out | FileCheck %s --check-prefix=CHECK3 -DPATTERN="de ad be ef"
-# RUN: od -t x1 -j 0x2300 -N 12 %t.out | FileCheck %s --check-prefix=CHECK4 -DPATTERN="de ad be ef"
-# RUN: od -t x1 -j 0x3000 -N 68 %t.out | FileCheck %s --check-prefix=CHECK5 -DPATTERN="de ad be ef"
-# RUN: od -t x1 -j 0x4000 -N 60 %t.out | FileCheck %s --check-prefix=CHECK6 -DPATTERN="de ad be ef"
-# RUN: od -t x1 -j 0x5000 -N 60 %t.out | FileCheck %s --check-prefix=CHECK7 -DPATTERN="de ad be ef"
+# RUN: od -t x1 -j 0x2000 -N 24 %t.out | FileCheck %s --ignore-case --check-prefix=CHECK1 -DPATTERN="de ad be ef"
+# RUN: od -t x1 -j 0x2100 -N 12 %t.out | FileCheck %s --ignore-case --check-prefix=CHECK2 -DPATTERN="de ad be ef"
+# RUN: od -t x1 -j 0x2200 -N 4  %t.out | FileCheck %s --ignore-case --check-prefix=CHECK3 -DPATTERN="de ad be ef"
+# RUN: od -t x1 -j 0x2300 -N 12 %t.out | FileCheck %s --ignore-case --check-prefix=CHECK4 -DPATTERN="de ad be ef"
+# RUN: od -t x1 -j 0x3000 -N 68 %t.out | FileCheck %s --ignore-case --check-prefix=CHECK5 -DPATTERN="de ad be ef"
+# RUN: od -t x1 -j 0x4000 -N 60 %t.out | FileCheck %s --ignore-case --check-prefix=CHECK6 -DPATTERN="de ad be ef"
+# RUN: od -t x1 -j 0x5000 -N 60 %t.out | FileCheck %s --ignore-case --check-prefix=CHECK7 -DPATTERN="de ad be ef"
 
 # CHECK1:      [[PATTERN]] 11 22 33 44 [[PATTERN]] [[PATTERN]]
 # CHECK1-NEXT: 55 66 77 88 [[PATTERN]]
Index: llvm/test/tools/llvm-objcopy/ELF/strip-all-gnu.test
===================================================================
--- llvm/test/tools/llvm-objcopy/ELF/strip-all-gnu.test
+++ llvm/test/tools/llvm-objcopy/ELF/strip-all-gnu.test
@@ -7,8 +7,8 @@
 # Show that the debug section in a segment was removed, to match GNU.
 # First validate that the offset in use is correct.
 # RUN: llvm-objcopy %t %t4
-# RUN: od -t x1 -N 4 -j 120 %t4 | FileCheck %s --check-prefix=COPY-BYTES
-# RUN: od -t x1 -N 4 -j 120 %t2 | FileCheck %s --check-prefix=STRIP-BYTES
+# RUN: od -t x1 -N 4 -j 120 %t4 | FileCheck %s --ignore-case --check-prefix=COPY-BYTES
+# RUN: od -t x1 -N 4 -j 120 %t2 | FileCheck %s --ignore-case --check-prefix=STRIP-BYTES
 
 !ELF
 FileHeader:
Index: llvm/test/tools/llvm-objcopy/ELF/strip-sections.test
===================================================================
--- llvm/test/tools/llvm-objcopy/ELF/strip-sections.test
+++ llvm/test/tools/llvm-objcopy/ELF/strip-sections.test
@@ -1,12 +1,12 @@
 # RUN: yaml2obj %s > %t
 # RUN: llvm-objcopy --strip-sections %t %t2
 # RUN: llvm-readobj --file-headers --program-headers %t2 | FileCheck %s
-# RUN: od -t x1 -j 4096 -N 12 %t2 | FileCheck %s --check-prefix=DATA
+# RUN: od -t x1 -j 4096 -N 12 %t2 | FileCheck %s --ignore-case --check-prefix=DATA
 
 ## Sanity check the DATA-NOT line by showing that "fe ed fa ce" appears
 ## if --strip-sections is not specified.
 # RUN: llvm-objcopy %t %t3
-# RUN: od -t x1 -j 4096 -N 12 %t3 | FileCheck %s --check-prefix=VALIDATE
+# RUN: od -t x1 -j 4096 -N 12 %t3 | FileCheck %s --ignore-case --check-prefix=VALIDATE
 
 ## Check that llvm-strip --strip-sections is equivalent to
 ## llvm-objcopy --strip-sections. 
Index: llvm/test/tools/yaml2obj/elf-override-shoffset.yaml
===================================================================
--- llvm/test/tools/yaml2obj/elf-override-shoffset.yaml
+++ llvm/test/tools/yaml2obj/elf-override-shoffset.yaml
@@ -75,7 +75,7 @@
 # RUN: yaml2obj --docnum=3 %s -o %t3
 # RUN: od -t x1 -v %t2 > %t.txt
 # RUN: od -t x1 -v %t3 >> %t.txt
-# RUN: FileCheck %s --input-file=%t.txt --check-prefix=CASE2
+# RUN: FileCheck %s --input-file=%t.txt --ignore-case --check-prefix=CASE2
 
 # CASE2: [[OFFSET:.*]] fe fe fe fe fe fe fe fe
 # CASE2: [[FILESIZE:.*]]{{$}}
Index: llvm/test/tools/yaml2obj/elf-override-shsize.yaml
===================================================================
--- llvm/test/tools/yaml2obj/elf-override-shsize.yaml
+++ llvm/test/tools/yaml2obj/elf-override-shsize.yaml
@@ -74,7 +74,7 @@
 # RUN: yaml2obj --docnum=3 %s -o %t3
 # RUN: od -t x1 -v %t2 > %t.txt
 # RUN: od -t x1 -v %t3 >> %t.txt
-# RUN: FileCheck %s --input-file=%t.txt --check-prefix=CASE2
+# RUN: FileCheck %s --input-file=%t.txt --ignore-case --check-prefix=CASE2
 
 # CASE2: [[OFFSET:.*]] fe fe fe fe fe fe fe fe
 # CASE2: [[FILESIZE:.*]]{{$}}
@@ -136,7 +136,7 @@
 ## bytes written is equal to Size in this case.
 
 # RUN: yaml2obj --docnum=5 %s -o %t5
-# RUN: od -t x1 -v %t5 | FileCheck %s --check-prefix=CASE5
+# RUN: od -t x1 -v %t5 | FileCheck %s --ignore-case --check-prefix=CASE5
 
 # CASE5: aa aa 00 00 bb bb
 
Index: llvm/utils/FileCheck/FileCheck.cpp
===================================================================
--- llvm/utils/FileCheck/FileCheck.cpp
+++ llvm/utils/FileCheck/FileCheck.cpp
@@ -48,6 +48,10 @@
     "strict-whitespace",
     cl::desc("Do not treat all horizontal whitespace as equivalent"));
 
+static cl::opt<bool> IgnoreCase(
+    "ignore-case",
+    cl::desc("Ignore case in comparisons"));
+
 static cl::list<std::string> ImplicitCheckNot(
     "implicit-check-not",
     cl::desc("Add an implicit negative check with this pattern to every\n"
@@ -555,6 +559,7 @@
   Req.VerboseVerbose = VerboseVerbose;
   Req.NoCanonicalizeWhiteSpace = NoCanonicalizeWhiteSpace;
   Req.MatchFullLines = MatchFullLines;
+  Req.IgnoreCase = IgnoreCase;
 
   if (VerboseVerbose)
     Req.Verbose = true;