diff --git a/flang/test/Frontend/input-output-file.f90 b/flang/test/Frontend/input-output-file.f90
--- a/flang/test/Frontend/input-output-file.f90
+++ b/flang/test/Frontend/input-output-file.f90
@@ -6,20 +6,19 @@
 ! FLANG DRIVER (flang-new)
 !--------------------------
 ! TEST 1: Print to stdout (implicit)
-! RUN: %flang-new -test-io %s  2>&1 | FileCheck %s
+! RUN: %flang-new -test-io %s  2>&1 | FileCheck %s --match-full-lines
 ! TEST 2: Print to stdout (explicit)
-! RUN: %flang-new -test-io -o - %s  2>&1 | FileCheck %s
+! RUN: %flang-new -test-io -o - %s  2>&1 | FileCheck %s --match-full-lines
 ! TEST 3: Print to a file
-! RUN: %flang-new -test-io -o %t %s 2>&1 && FileCheck %s --input-file=%t
+! RUN: %flang-new -test-io -o %t %s 2>&1 && FileCheck %s --match-full-lines --input-file=%t
 
 !----------------------------------------
 ! FLANG FRONTEND DRIVER (flang-new -fc1)
 !----------------------------------------
 ! TEST 4: Write to a file (implicit)
-! RUN: %flang-new -fc1 -test-io  %s 2>&1 && FileCheck %s --input-file=%S/input-output-file.txt
+! RUN: %flang-new -fc1 -test-io  %s 2>&1 && FileCheck %s --match-full-lines --input-file=%S/input-output-file.txt
 ! TEST 5: Write to a file (explicit)
-! RUN: %flang-new -fc1 -test-io  -o %t %s 2>&1 && FileCheck %s --input-file=%t
-
+! RUN: %flang-new -fc1 -test-io  -o %t %s 2>&1 && FileCheck %s --match-full-lines --input-file=%t
 
 !-----------------------
 ! EXPECTED OUTPUT
@@ -32,4 +31,4 @@
 Program arithmetic
   Integer :: i, j
   i = 2; j = 3; i= i * j;
-End Program arithmetic
\ No newline at end of file
+End Program arithmetic
diff --git a/flang/test/Frontend/multiple-input-files.f90 b/flang/test/Frontend/multiple-input-files.f90
--- a/flang/test/Frontend/multiple-input-files.f90
+++ b/flang/test/Frontend/multiple-input-files.f90
@@ -6,54 +6,62 @@
 ! FLANG DRIVER (flang-new)
 !--------------------------
 ! TEST 1: Both input files are processed (output is printed to stdout)
-! RUN: %flang-new -test-io %s %S/Inputs/hello-world.f90 | FileCheck %s  -check-prefix=flang-new
+! RUN: %flang-new -test-io %s %S/Inputs/hello-world.f90 | FileCheck %s --match-full-lines -check-prefix=FLANG
 
 ! TEST 2: None of the files is processed (not possible to specify the output file when multiple input files are present)
-! RUN: not %flang-new -test-io -o - %S/Inputs/hello-world.f90 %s  2>&1 | FileCheck %s -check-prefix=ERROR
-! RUN: not %flang-new -test-io -o %t %S/Inputs/hello-world.f90 %s 2>&1 | FileCheck %s -check-prefix=ERROR
+! RUN: not %flang-new -test-io -o - %S/Inputs/hello-world.f90 %s  2>&1 | FileCheck %s --match-full-lines -check-prefix=ERROR
+! RUN: not %flang-new -test-io -o %t %S/Inputs/hello-world.f90 %s 2>&1 | FileCheck %s --match-full-lines -check-prefix=ERROR
 
 !----------------------------------------
 ! FLANG FRONTEND DRIVER (flang-new -fc1)
 !----------------------------------------
 ! TEST 3: Both input files are processed
 ! RUN: %flang-new -fc1 -test-io  %S/Inputs/hello-world.f90 %s 2>&1 \
-! RUN:  && FileCheck %s --input-file=%S/multiple-input-files.txt -check-prefix=flang-new-FC1-OUTPUT1 
+! RUN:  && FileCheck %s --input-file=%S/multiple-input-files.txt --match-full-lines -check-prefix=FC1-OUTPUT1 \
+! RUN:  && FileCheck %s --input-file=%S/Inputs/hello-world.txt --match-full-lines -check-prefix=FC1-OUTPUT2
 
 ! TEST 4: Only the last input file is processed
-! RUN: %flang-new -fc1 -test-io  %S/Inputs/hello-world.f90 %s -o %t 2>&1 \
-! RUN:  && FileCheck %s --input-file=%t -check-prefix=flang-new-FC1-OUTPUT1
+! RUN: %flang-new -fc1 -test-io %s %S/Inputs/hello-world.f90 -o %t 2>&1 \
+! RUN:  && FileCheck %s --input-file=%t --match-full-lines -check-prefix=FC1-OUTPUT3
 
 !-----------------------
 ! EXPECTED OUTPUT
 !-----------------------
 ! TEST 1: By default, `flang-new` prints the output from all input files to
 ! stdout
-! flang-new-LABEL: Program arithmetic
-! flang-new-NEXT:    Integer :: i, j
-! flang-new-NEXT:    i = 2; j = 3; i= i * j;
-! flang-new-NEXT:  End Program arithmetic
-! flang-new-NEXT: !This is a test file with a hello world in Fortran
-! flang-new-NEXT:program hello
-! flang-new-NEXT:  implicit none
-! flang-new-NEXT:  write(*,*) 'Hello world!'
-! flang-new-NEXT:end program hello
-
+! FLANG-LABEL: Program arithmetic
+! FLANG-NEXT:    Integer :: i, j
+! FLANG-NEXT:    i = 2; j = 3; i= i * j;
+! FLANG-NEXT:  End Program arithmetic
+! FLANG-NEXT:!This is a test file with a hello world in Fortran
+! FLANG-NEXT:program hello
+! FLANG-NEXT:  implicit none
+! FLANG-NEXT:  write(*,*) 'Hello world!'
+! FLANG-NEXT:end program hello
 
 ! TEST 2: `-o` does not work for `flang-new` when multiple input files are present
-! ERROR:error: cannot specify -o when generating multiple output files
-
-
-! TEST 3 & TEST 4: Unless the output file is specified, `flang-new -fc1` generates one output file for every input file. If an
-! output file is specified (with `-o`), then only the last input file is processed.
-! flang-new-FC1-OUTPUT1-LABEL: Program arithmetic
-! flang-new-FC1-OUTPUT1-NEXT:    Integer :: i, j
-! flang-new-FC1-OUTPUT1-NEXT:    i = 2; j = 3; i= i * j;
-! flang-new-FC1-OUTPUT1-NEXT:  End Program arithmetic
-! flang-new-FC1-OUTPUT1-NEXT: !This is a test file with a hello world in Fortran
-! flang-new-FC1-OUTPUT1-NEXT:program hello
-! flang-new-FC1-OUTPUT1-NEXT:  implicit none
-! flang-new-FC1-OUTPUT1-NEXT:  write(*,*) 'Hello world!'
-! flang-new-FC1-OUTPUT1-NEXT:end program hello
+! ERROR: flang-new: error: cannot specify -o when generating multiple output files
+
+! TEST 3: The output file _was not_ specified - `flang-new -fc1` will process all
+! input files and generate one output file for every input file.
+! FC1-OUTPUT1-LABEL: Program arithmetic
+! FC1-OUTPUT1-NEXT:    Integer :: i, j
+! FC1-OUTPUT1-NEXT:    i = 2; j = 3; i= i * j;
+! FC1-OUTPUT1-NEXT:  End Program arithmetic
+
+! FC1-OUTPUT2-LABEL:!This is a test file with a hello world in Fortran
+! FC1-OUTPUT2-NEXT:program hello
+! FC1-OUTPUT2-NEXT:  implicit none
+! FC1-OUTPUT2-NEXT:  write(*,*) 'Hello world!'
+! FC1-OUTPUT2-NEXT:end program hello
+
+! TEST 4: The output file _was_ specified - `flang-new -fc1` will process only
+! the last input file and generate the corresponding output.
+! FC1-OUTPUT3-LABEL:!This is a test file with a hello world in Fortran
+! FC1-OUTPUT3-NEXT:program hello
+! FC1-OUTPUT3-NEXT:  implicit none
+! FC1-OUTPUT3-NEXT:  write(*,*) 'Hello world!'
+! FC1-OUTPUT3-NEXT:end program hello
 
 
 Program arithmetic