ART: Refactored regex code in Checker

This patch refactors how Checker constructs regular expressions which
it uses to parse tests and verify compiler output. It also replaces
all occurrences of the '[0-9]+' ID-matching expression with the '\d+'
shorthand.

Change-Id: I5f854a25707e44ed2fa1673ff084990e8f43e4a2

3 files changed, 143 insertions, 145 deletions

diff --git a/compiler/optimizing/test/ConstantFolding.java b/compiler/optimizing/test/ConstantFolding.java
index 92f2a77..d08006b 100644
--- a/compiler/optimizing/test/ConstantFolding.java
+++ b/compiler/optimizing/test/ConstantFolding.java
@@ -22,13 +22,13 @@ public class ConstantFolding {
    */
 
   // CHECK-START: int ConstantFolding.IntNegation() constant_folding (before)
-  // CHECK-DAG:     [[Const42:i[0-9]+]]  IntConstant 42
-  // CHECK-DAG:     [[Neg:i[0-9]+]]      Neg [ [[Const42]] ]
-  // CHECK-DAG:                          Return [ [[Neg]] ]
+  // CHECK-DAG:     [[Const42:i\d+]]  IntConstant 42
+  // CHECK-DAG:     [[Neg:i\d+]]      Neg [ [[Const42]] ]
+  // CHECK-DAG:                       Return [ [[Neg]] ]
 
   // CHECK-START: int ConstantFolding.IntNegation() constant_folding (after)
-  // CHECK-DAG:     [[ConstN42:i[0-9]+]] IntConstant -42
-  // CHECK-DAG:                          Return [ [[ConstN42]] ]
+  // CHECK-DAG:     [[ConstN42:i\d+]] IntConstant -42
+  // CHECK-DAG:                       Return [ [[ConstN42]] ]
 
   public static int IntNegation() {
     int x, y;
@@ -43,14 +43,14 @@ public class ConstantFolding {
    */
 
   // CHECK-START: int ConstantFolding.IntAddition1() constant_folding (before)
-  // CHECK-DAG:     [[Const1:i[0-9]+]]  IntConstant 1
-  // CHECK-DAG:     [[Const2:i[0-9]+]]  IntConstant 2
-  // CHECK-DAG:     [[Add:i[0-9]+]]     Add [ [[Const1]] [[Const2]] ]
-  // CHECK-DAG:                         Return [ [[Add]] ]
+  // CHECK-DAG:     [[Const1:i\d+]]  IntConstant 1
+  // CHECK-DAG:     [[Const2:i\d+]]  IntConstant 2
+  // CHECK-DAG:     [[Add:i\d+]]     Add [ [[Const1]] [[Const2]] ]
+  // CHECK-DAG:                      Return [ [[Add]] ]
 
   // CHECK-START: int ConstantFolding.IntAddition1() constant_folding (after)
-  // CHECK-DAG:     [[Const3:i[0-9]+]]  IntConstant 3
-  // CHECK-DAG:                         Return [ [[Const3]] ]
+  // CHECK-DAG:     [[Const3:i\d+]]  IntConstant 3
+  // CHECK-DAG:                      Return [ [[Const3]] ]
 
   public static int IntAddition1() {
     int a, b, c;
@@ -66,18 +66,18 @@ public class ConstantFolding {
   */
 
   // CHECK-START: int ConstantFolding.IntAddition2() constant_folding (before)
-  // CHECK-DAG:     [[Const1:i[0-9]+]]  IntConstant 1
-  // CHECK-DAG:     [[Const2:i[0-9]+]]  IntConstant 2
-  // CHECK-DAG:     [[Const5:i[0-9]+]]  IntConstant 5
-  // CHECK-DAG:     [[Const6:i[0-9]+]]  IntConstant 6
-  // CHECK-DAG:     [[Add1:i[0-9]+]]    Add [ [[Const1]] [[Const2]] ]
-  // CHECK-DAG:     [[Add2:i[0-9]+]]    Add [ [[Const5]] [[Const6]] ]
-  // CHECK-DAG:     [[Add3:i[0-9]+]]    Add [ [[Add1]] [[Add2]] ]
-  // CHECK-DAG:                         Return [ [[Add3]] ]
+  // CHECK-DAG:     [[Const1:i\d+]]  IntConstant 1
+  // CHECK-DAG:     [[Const2:i\d+]]  IntConstant 2
+  // CHECK-DAG:     [[Const5:i\d+]]  IntConstant 5
+  // CHECK-DAG:     [[Const6:i\d+]]  IntConstant 6
+  // CHECK-DAG:     [[Add1:i\d+]]    Add [ [[Const1]] [[Const2]] ]
+  // CHECK-DAG:     [[Add2:i\d+]]    Add [ [[Const5]] [[Const6]] ]
+  // CHECK-DAG:     [[Add3:i\d+]]    Add [ [[Add1]] [[Add2]] ]
+  // CHECK-DAG:                      Return [ [[Add3]] ]
 
   // CHECK-START: int ConstantFolding.IntAddition2() constant_folding (after)
-  // CHECK-DAG:     [[Const14:i[0-9]+]] IntConstant 14
-  // CHECK-DAG:                         Return [ [[Const14]] ]
+  // CHECK-DAG:     [[Const14:i\d+]] IntConstant 14
+  // CHECK-DAG:                      Return [ [[Const14]] ]
 
   public static int IntAddition2() {
     int a, b, c;
@@ -97,14 +97,14 @@ public class ConstantFolding {
    */
 
   // CHECK-START: int ConstantFolding.IntSubtraction() constant_folding (before)
-  // CHECK-DAG:     [[Const5:i[0-9]+]]  IntConstant 5
-  // CHECK-DAG:     [[Const2:i[0-9]+]]  IntConstant 2
-  // CHECK-DAG:     [[Sub:i[0-9]+]]     Sub [ [[Const5]] [[Const2]] ]
-  // CHECK-DAG:                         Return [ [[Sub]] ]
+  // CHECK-DAG:     [[Const5:i\d+]]  IntConstant 5
+  // CHECK-DAG:     [[Const2:i\d+]]  IntConstant 2
+  // CHECK-DAG:     [[Sub:i\d+]]     Sub [ [[Const5]] [[Const2]] ]
+  // CHECK-DAG:                      Return [ [[Sub]] ]
 
   // CHECK-START: int ConstantFolding.IntSubtraction() constant_folding (after)
-  // CHECK-DAG:     [[Const3:i[0-9]+]]  IntConstant 3
-  // CHECK-DAG:                         Return [ [[Const3]] ]
+  // CHECK-DAG:     [[Const3:i\d+]]  IntConstant 3
+  // CHECK-DAG:                      Return [ [[Const3]] ]
 
   public static int IntSubtraction() {
     int a, b, c;
@@ -120,14 +120,14 @@ public class ConstantFolding {
    */
 
   // CHECK-START: long ConstantFolding.LongAddition() constant_folding (before)
-  // CHECK-DAG:     [[Const1:j[0-9]+]]  LongConstant 1
-  // CHECK-DAG:     [[Const2:j[0-9]+]]  LongConstant 2
-  // CHECK-DAG:     [[Add:j[0-9]+]]     Add [ [[Const1]] [[Const2]] ]
-  // CHECK-DAG:                         Return [ [[Add]] ]
+  // CHECK-DAG:     [[Const1:j\d+]]  LongConstant 1
+  // CHECK-DAG:     [[Const2:j\d+]]  LongConstant 2
+  // CHECK-DAG:     [[Add:j\d+]]     Add [ [[Const1]] [[Const2]] ]
+  // CHECK-DAG:                      Return [ [[Add]] ]
 
   // CHECK-START: long ConstantFolding.LongAddition() constant_folding (after)
-  // CHECK-DAG:     [[Const3:j[0-9]+]]  LongConstant 3
-  // CHECK-DAG:                         Return [ [[Const3]] ]
+  // CHECK-DAG:     [[Const3:j\d+]]  LongConstant 3
+  // CHECK-DAG:                      Return [ [[Const3]] ]
 
   public static long LongAddition() {
     long a, b, c;
@@ -143,14 +143,14 @@ public class ConstantFolding {
    */
 
   // CHECK-START: long ConstantFolding.LongSubtraction() constant_folding (before)
-  // CHECK-DAG:     [[Const5:j[0-9]+]]  LongConstant 5
-  // CHECK-DAG:     [[Const2:j[0-9]+]]  LongConstant 2
-  // CHECK-DAG:     [[Sub:j[0-9]+]]     Sub [ [[Const5]] [[Const2]] ]
-  // CHECK-DAG:                         Return [ [[Sub]] ]
+  // CHECK-DAG:     [[Const5:j\d+]]  LongConstant 5
+  // CHECK-DAG:     [[Const2:j\d+]]  LongConstant 2
+  // CHECK-DAG:     [[Sub:j\d+]]     Sub [ [[Const5]] [[Const2]] ]
+  // CHECK-DAG:                      Return [ [[Sub]] ]
 
   // CHECK-START: long ConstantFolding.LongSubtraction() constant_folding (after)
-  // CHECK-DAG:     [[Const3:j[0-9]+]]  LongConstant 3
-  // CHECK-DAG:                         Return [ [[Const3]] ]
+  // CHECK-DAG:     [[Const3:j\d+]]  LongConstant 3
+  // CHECK-DAG:                      Return [ [[Const3]] ]
 
   public static long LongSubtraction() {
     long a, b, c;
@@ -165,14 +165,14 @@ public class ConstantFolding {
    */
 
   // CHECK-START: int ConstantFolding.StaticCondition() constant_folding (before)
-  // CHECK-DAG:     [[Const5:i[0-9]+]]  IntConstant 5
-  // CHECK-DAG:     [[Const2:i[0-9]+]]  IntConstant 2
-  // CHECK-DAG:     [[Cond:z[0-9]+]]    GreaterThanOrEqual [ [[Const5]] [[Const2]] ]
-  // CHECK-DAG:                         If [ [[Cond]] ]
+  // CHECK-DAG:     [[Const5:i\d+]]  IntConstant 5
+  // CHECK-DAG:     [[Const2:i\d+]]  IntConstant 2
+  // CHECK-DAG:     [[Cond:z\d+]]    GreaterThanOrEqual [ [[Const5]] [[Const2]] ]
+  // CHECK-DAG:                      If [ [[Cond]] ]
 
   // CHECK-START: int ConstantFolding.StaticCondition() constant_folding (after)
-  // CHECK-DAG:     [[Const1:i[0-9]+]]  IntConstant 1
-  // CHECK-DAG:                         If [ [[Const1]] ]
+  // CHECK-DAG:     [[Const1:i\d+]]  IntConstant 1
+  // CHECK-DAG:                      If [ [[Const1]] ]
 
   public static int StaticCondition() {
     int a, b, c;
@@ -195,18 +195,18 @@ public class ConstantFolding {
    */
 
   // CHECK-START: int ConstantFolding.JumpsAndConditionals(boolean) constant_folding (before)
-  // CHECK-DAG:     [[Const2:i[0-9]+]]  IntConstant 2
-  // CHECK-DAG:     [[Const5:i[0-9]+]]  IntConstant 5
-  // CHECK-DAG:     [[Add:i[0-9]+]]     Add [ [[Const5]] [[Const2]] ]
-  // CHECK-DAG:     [[Sub:i[0-9]+]]     Sub [ [[Const5]] [[Const2]] ]
-  // CHECK-DAG:     [[Phi:i[0-9]+]]     Phi [ [[Add]] [[Sub]] ]
-  // CHECK-DAG:                         Return [ [[Phi]] ]
+  // CHECK-DAG:     [[Const2:i\d+]]  IntConstant 2
+  // CHECK-DAG:     [[Const5:i\d+]]  IntConstant 5
+  // CHECK-DAG:     [[Add:i\d+]]     Add [ [[Const5]] [[Const2]] ]
+  // CHECK-DAG:     [[Sub:i\d+]]     Sub [ [[Const5]] [[Const2]] ]
+  // CHECK-DAG:     [[Phi:i\d+]]     Phi [ [[Add]] [[Sub]] ]
+  // CHECK-DAG:                      Return [ [[Phi]] ]
 
   // CHECK-START: int ConstantFolding.JumpsAndConditionals(boolean) constant_folding (after)
-  // CHECK-DAG:     [[Const3:i[0-9]+]]  IntConstant 3
-  // CHECK-DAG:     [[Const7:i[0-9]+]]  IntConstant 7
-  // CHECK-DAG:     [[Phi:i[0-9]+]]     Phi [ [[Const7]] [[Const3]] ]
-  // CHECK-DAG:                         Return [ [[Phi]] ]
+  // CHECK-DAG:     [[Const3:i\d+]]  IntConstant 3
+  // CHECK-DAG:     [[Const7:i\d+]]  IntConstant 7
+  // CHECK-DAG:     [[Phi:i\d+]]     Phi [ [[Const7]] [[Const3]] ]
+  // CHECK-DAG:                      Return [ [[Phi]] ]
 
   public static int JumpsAndConditionals(boolean cond) {
     int a, b, c;
diff --git a/compiler/optimizing/test/Inliner.java b/compiler/optimizing/test/Inliner.java
index ce7409c..54cce62 100644
--- a/compiler/optimizing/test/Inliner.java
+++ b/compiler/optimizing/test/Inliner.java
@@ -17,12 +17,12 @@
 public class Inliner {
 
   // CHECK-START: void Inliner.InlineVoid() inliner (before)
-  // CHECK-DAG:     [[Const42:i[0-9]+]] IntConstant 42
-  // CHECK-DAG:                         InvokeStaticOrDirect
-  // CHECK-DAG:                         InvokeStaticOrDirect [ [[Const42]] ]
+  // CHECK-DAG:     [[Const42:i\d+]] IntConstant 42
+  // CHECK-DAG:                      InvokeStaticOrDirect
+  // CHECK-DAG:                      InvokeStaticOrDirect [ [[Const42]] ]
 
   // CHECK-START: void Inliner.InlineVoid() inliner (after)
-  // CHECK-NOT:                         InvokeStaticOrDirect
+  // CHECK-NOT:                      InvokeStaticOrDirect
 
   public static void InlineVoid() {
     returnVoid();
@@ -30,119 +30,119 @@ public class Inliner {
   }
 
   // CHECK-START: int Inliner.InlineParameter(int) inliner (before)
-  // CHECK-DAG:     [[Param:i[0-9]+]]  ParameterValue
-  // CHECK-DAG:     [[Result:i[0-9]+]] InvokeStaticOrDirect [ [[Param]] ]
-  // CHECK-DAG:                        Return [ [[Result]] ]
+  // CHECK-DAG:     [[Param:i\d+]]  ParameterValue
+  // CHECK-DAG:     [[Result:i\d+]] InvokeStaticOrDirect [ [[Param]] ]
+  // CHECK-DAG:                     Return [ [[Result]] ]
 
   // CHECK-START: int Inliner.InlineParameter(int) inliner (after)
-  // CHECK-DAG:     [[Param:i[0-9]+]]  ParameterValue
-  // CHECK-DAG:                        Return [ [[Param]] ]
+  // CHECK-DAG:     [[Param:i\d+]]  ParameterValue
+  // CHECK-DAG:                     Return [ [[Param]] ]
 
   public static int InlineParameter(int a) {
     return returnParameter(a);
   }
 
   // CHECK-START: long Inliner.InlineWideParameter(long) inliner (before)
-  // CHECK-DAG:     [[Param:j[0-9]+]]  ParameterValue
-  // CHECK-DAG:     [[Result:j[0-9]+]] InvokeStaticOrDirect [ [[Param]] ]
-  // CHECK-DAG:                        Return [ [[Result]] ]
+  // CHECK-DAG:     [[Param:j\d+]]  ParameterValue
+  // CHECK-DAG:     [[Result:j\d+]] InvokeStaticOrDirect [ [[Param]] ]
+  // CHECK-DAG:                     Return [ [[Result]] ]
 
   // CHECK-START: long Inliner.InlineWideParameter(long) inliner (after)
-  // CHECK-DAG:     [[Param:j[0-9]+]]  ParameterValue
-  // CHECK-DAG:                        Return [ [[Param]] ]
+  // CHECK-DAG:     [[Param:j\d+]]  ParameterValue
+  // CHECK-DAG:                     Return [ [[Param]] ]
 
   public static long InlineWideParameter(long a) {
     return returnWideParameter(a);
   }
 
   // CHECK-START: java.lang.Object Inliner.InlineReferenceParameter(java.lang.Object) inliner (before)
-  // CHECK-DAG:     [[Param:l[0-9]+]]  ParameterValue
-  // CHECK-DAG:     [[Result:l[0-9]+]] InvokeStaticOrDirect [ [[Param]] ]
-  // CHECK-DAG:                        Return [ [[Result]] ]
+  // CHECK-DAG:     [[Param:l\d+]]  ParameterValue
+  // CHECK-DAG:     [[Result:l\d+]] InvokeStaticOrDirect [ [[Param]] ]
+  // CHECK-DAG:                     Return [ [[Result]] ]
 
   // CHECK-START: java.lang.Object Inliner.InlineReferenceParameter(java.lang.Object) inliner (after)
-  // CHECK-DAG:     [[Param:l[0-9]+]]  ParameterValue
-  // CHECK-DAG:                        Return [ [[Param]] ]
+  // CHECK-DAG:     [[Param:l\d+]]  ParameterValue
+  // CHECK-DAG:                     Return [ [[Param]] ]
 
   public static Object InlineReferenceParameter(Object o) {
     return returnReferenceParameter(o);
   }
 
   // CHECK-START: int Inliner.InlineInt() inliner (before)
-  // CHECK-DAG:     [[Result:i[0-9]+]] InvokeStaticOrDirect
-  // CHECK-DAG:                        Return [ [[Result]] ]
+  // CHECK-DAG:     [[Result:i\d+]] InvokeStaticOrDirect
+  // CHECK-DAG:                     Return [ [[Result]] ]
 
   // CHECK-START: int Inliner.InlineInt() inliner (after)
-  // CHECK-DAG:     [[Const4:i[0-9]+]] IntConstant 4
-  // CHECK-DAG:                        Return [ [[Const4]] ]
+  // CHECK-DAG:     [[Const4:i\d+]] IntConstant 4
+  // CHECK-DAG:                     Return [ [[Const4]] ]
 
   public static int InlineInt() {
     return returnInt();
   }
 
   // CHECK-START: long Inliner.InlineWide() inliner (before)
-  // CHECK-DAG:     [[Result:j[0-9]+]] InvokeStaticOrDirect
-  // CHECK-DAG:                        Return [ [[Result]] ]
+  // CHECK-DAG:     [[Result:j\d+]] InvokeStaticOrDirect
+  // CHECK-DAG:                     Return [ [[Result]] ]
 
   // CHECK-START: long Inliner.InlineWide() inliner (after)
-  // CHECK-DAG:     [[Const8:j[0-9]+]] LongConstant 8
-  // CHECK-DAG:                        Return [ [[Const8]] ]
+  // CHECK-DAG:     [[Const8:j\d+]] LongConstant 8
+  // CHECK-DAG:                     Return [ [[Const8]] ]
 
   public static long InlineWide() {
     return returnWide();
   }
 
   // CHECK-START: int Inliner.InlineAdd() inliner (before)
-  // CHECK-DAG:     [[Const3:i[0-9]+]] IntConstant 3
-  // CHECK-DAG:     [[Const5:i[0-9]+]] IntConstant 5
-  // CHECK-DAG:     [[Result:i[0-9]+]] InvokeStaticOrDirect
-  // CHECK-DAG:                        Return [ [[Result]] ]
+  // CHECK-DAG:     [[Const3:i\d+]] IntConstant 3
+  // CHECK-DAG:     [[Const5:i\d+]] IntConstant 5
+  // CHECK-DAG:     [[Result:i\d+]] InvokeStaticOrDirect
+  // CHECK-DAG:                     Return [ [[Result]] ]
 
   // CHECK-START: int Inliner.InlineAdd() inliner (after)
-  // CHECK-DAG:     [[Const3:i[0-9]+]] IntConstant 3
-  // CHECK-DAG:     [[Const5:i[0-9]+]] IntConstant 5
-  // CHECK-DAG:     [[Add:i[0-9]+]]    Add [ [[Const3]] [[Const5]] ]
-  // CHECK-DAG:                        Return [ [[Add]] ]
+  // CHECK-DAG:     [[Const3:i\d+]] IntConstant 3
+  // CHECK-DAG:     [[Const5:i\d+]] IntConstant 5
+  // CHECK-DAG:     [[Add:i\d+]]    Add [ [[Const3]] [[Const5]] ]
+  // CHECK-DAG:                     Return [ [[Add]] ]
 
   public static int InlineAdd() {
     return returnAdd(3, 5);
   }
 
   // CHECK-START: int Inliner.InlineFieldAccess() inliner (before)
-  // CHECK-DAG:     [[After:i[0-9]+]]  InvokeStaticOrDirect
-  // CHECK-DAG:                        Return [ [[After]] ]
+  // CHECK-DAG:     [[After:i\d+]]  InvokeStaticOrDirect
+  // CHECK-DAG:                     Return [ [[After]] ]
 
   // CHECK-START: int Inliner.InlineFieldAccess() inliner (after)
-  // CHECK-DAG:     [[Const1:i[0-9]+]] IntConstant 1
-  // CHECK-DAG:     [[Before:i[0-9]+]] StaticFieldGet
-  // CHECK-DAG:     [[After:i[0-9]+]]  Add [ [[Before]] [[Const1]] ]
-  // CHECK-DAG:                        StaticFieldSet [ {{l[0-9]+}} [[After]] ]
-  // CHECK-DAG:                        Return [ [[After]] ]
+  // CHECK-DAG:     [[Const1:i\d+]] IntConstant 1
+  // CHECK-DAG:     [[Before:i\d+]] StaticFieldGet
+  // CHECK-DAG:     [[After:i\d+]]  Add [ [[Before]] [[Const1]] ]
+  // CHECK-DAG:                     StaticFieldSet [ {{l\d+}} [[After]] ]
+  // CHECK-DAG:                     Return [ [[After]] ]
 
   // CHECK-START: int Inliner.InlineFieldAccess() inliner (after)
-  // CHECK-NOT:                        InvokeStaticOrDirect
+  // CHECK-NOT:                     InvokeStaticOrDirect
 
   public static int InlineFieldAccess() {
     return incCounter();
   }
 
   // CHECK-START: int Inliner.InlineWithControlFlow(boolean) inliner (before)
-  // CHECK-DAG:     [[Const1:i[0-9]+]] IntConstant 1
-  // CHECK-DAG:     [[Const3:i[0-9]+]] IntConstant 3
-  // CHECK-DAG:     [[Const5:i[0-9]+]] IntConstant 5
-  // CHECK-DAG:     [[Add:i[0-9]+]]    InvokeStaticOrDirect [ [[Const1]] [[Const3]] ]
-  // CHECK-DAG:     [[Sub:i[0-9]+]]    InvokeStaticOrDirect [ [[Const5]] [[Const3]] ]
-  // CHECK-DAG:     [[Phi:i[0-9]+]]    Phi [ [[Add]] [[Sub]] ]
-  // CHECK-DAG:                        Return [ [[Phi]] ]
+  // CHECK-DAG:     [[Const1:i\d+]] IntConstant 1
+  // CHECK-DAG:     [[Const3:i\d+]] IntConstant 3
+  // CHECK-DAG:     [[Const5:i\d+]] IntConstant 5
+  // CHECK-DAG:     [[Add:i\d+]]    InvokeStaticOrDirect [ [[Const1]] [[Const3]] ]
+  // CHECK-DAG:     [[Sub:i\d+]]    InvokeStaticOrDirect [ [[Const5]] [[Const3]] ]
+  // CHECK-DAG:     [[Phi:i\d+]]    Phi [ [[Add]] [[Sub]] ]
+  // CHECK-DAG:                     Return [ [[Phi]] ]
 
   // CHECK-START: int Inliner.InlineWithControlFlow(boolean) inliner (after)
-  // CHECK-DAG:     [[Const1:i[0-9]+]] IntConstant 1
-  // CHECK-DAG:     [[Const3:i[0-9]+]] IntConstant 3
-  // CHECK-DAG:     [[Const5:i[0-9]+]] IntConstant 5
-  // CHECK-DAG:     [[Add:i[0-9]+]]    Add [ [[Const1]] [[Const3]] ]
-  // CHECK-DAG:     [[Sub:i[0-9]+]]    Sub [ [[Const5]] [[Const3]] ]
-  // CHECK-DAG:     [[Phi:i[0-9]+]]    Phi [ [[Add]] [[Sub]] ]
-  // CHECK-DAG:                        Return [ [[Phi]] ]
+  // CHECK-DAG:     [[Const1:i\d+]] IntConstant 1
+  // CHECK-DAG:     [[Const3:i\d+]] IntConstant 3
+  // CHECK-DAG:     [[Const5:i\d+]] IntConstant 5
+  // CHECK-DAG:     [[Add:i\d+]]    Add [ [[Const1]] [[Const3]] ]
+  // CHECK-DAG:     [[Sub:i\d+]]    Sub [ [[Const5]] [[Const3]] ]
+  // CHECK-DAG:     [[Phi:i\d+]]    Phi [ [[Add]] [[Sub]] ]
+  // CHECK-DAG:                     Return [ [[Phi]] ]
 
   public static int InlineWithControlFlow(boolean cond) {
     int x, const1, const3, const5;
diff --git a/tools/checker.py b/tools/checker.py
index 5e910ec..b1abea2 100755
--- a/tools/checker.py
+++ b/tools/checker.py
@@ -159,6 +159,23 @@ class CheckElement(CommonEqualityMixin):
     """Supported language constructs."""
     Text, Pattern, VarRef, VarDef = range(4)
 
+  rStartOptional = r"("
+  rEndOptional = r")?"
+
+  rName = r"([a-zA-Z][a-zA-Z0-9]*)"
+  rRegex = r"(.+?)"
+  rPatternStartSym = r"(\{\{)"
+  rPatternEndSym = r"(\}\})"
+  rVariableStartSym = r"(\[\[)"
+  rVariableEndSym = r"(\]\])"
+  rVariableSeparator = r"(:)"
+
+  regexPattern = rPatternStartSym + rRegex + rPatternEndSym
+  regexVariable = rVariableStartSym + \
+                    rName + \
+                    (rStartOptional + rVariableSeparator + rRegex + rEndOptional) + \
+                  rVariableEndSym
+
   def __init__(self, variant, name, pattern):
     self.variant = variant
     self.name = name
@@ -170,22 +187,21 @@ class CheckElement(CommonEqualityMixin):
 
   @staticmethod
   def parsePattern(patternElem):
-    return CheckElement(CheckElement.Variant.Pattern, None, patternElem[2:len(patternElem)-2])
+    return CheckElement(CheckElement.Variant.Pattern, None, patternElem[2:-2])
 
   @staticmethod
   def parseVariable(varElem):
     colonPos = varElem.find(":")
     if colonPos == -1:
       # Variable reference
-      name = varElem[2:len(varElem)-2]
+      name = varElem[2:-2]
       return CheckElement(CheckElement.Variant.VarRef, name, None)
     else:
       # Variable definition
       name = varElem[2:colonPos]
-      body = varElem[colonPos+1:len(varElem)-2]
+      body = varElem[colonPos+1:-2]
       return CheckElement(CheckElement.Variant.VarDef, name, body)
 
-
 class CheckLine(CommonEqualityMixin):
   """Representation of a single assertion in the check file formed of one or
      more regex elements. Matching against an output line is successful only
@@ -226,24 +242,6 @@ class CheckLine(CommonEqualityMixin):
     starts = map(lambda m: len(string) if m is None else m.start(), matches)
     return min(starts)
 
-  # Returns the regex for finding a regex pattern in the check line.
-  def __getPatternRegex(self):
-    rStartSym = "\{\{"
-    rEndSym = "\}\}"
-    rBody = ".+?"
-    return rStartSym + rBody + rEndSym
-
-  # Returns the regex for finding a variable use in the check line.
-  def __getVariableRegex(self):
-    rStartSym = "\[\["
-    rEndSym = "\]\]"
-    rStartOptional = "("
-    rEndOptional = ")?"
-    rName = "[a-zA-Z][a-zA-Z0-9]*"
-    rSeparator = ":"
-    rBody = ".+?"
-    return rStartSym + rName + rStartOptional + rSeparator + rBody + rEndOptional + rEndSym
-
   # This method parses the content of a check line stripped of the initial
   # comment symbol and the CHECK keyword.
   def __parse(self, line):
@@ -251,9 +249,9 @@ class CheckLine(CommonEqualityMixin):
     # Loop as long as there is something to parse.
     while line:
       # Search for the nearest occurrence of the special markers.
-      matchWhitespace = re.search("\s+", line)
-      matchPattern = re.search(self.__getPatternRegex(), line)
-      matchVariable = re.search(self.__getVariableRegex(), line)
+      matchWhitespace = re.search(r"\s+", line)
+      matchPattern = re.search(CheckElement.regexPattern, line)
+      matchVariable = re.search(CheckElement.regexVariable, line)
 
       # If one of the above was identified at the current position, extract them
       # from the line, parse them and add to the list of line parts.
@@ -262,7 +260,7 @@ class CheckLine(CommonEqualityMixin):
         # a whitespace, we add a regex pattern for an arbitrary non-zero number
         # of whitespaces.
         line = line[matchWhitespace.end():]
-        lineParts.append(CheckElement.parsePattern("{{\s+}}"))
+        lineParts.append(CheckElement.parsePattern(r"{{\s+}}"))
       elif self.__isMatchAtStart(matchPattern):
         pattern = line[0:matchPattern.end()]
         line = line[matchPattern.end():]
@@ -536,16 +534,16 @@ class CheckFile(FileSplitMixin):
   # followed by the CHECK keyword, given attribute and a colon at the very
   # beginning of the line. Whitespaces are ignored.
   def _extractLine(self, prefix, line):
-    ignoreWhitespace = "\s*"
-    commentSymbols = ["//", "#"]
-    prefixRegex = ignoreWhitespace + \
-                  "(" + "|".join(commentSymbols) + ")" + \
-                  ignoreWhitespace + \
-                  prefix + ":"
+    rIgnoreWhitespace = r"\s*"
+    rCommentSymbols = [r"//", r"#"]
+    regexPrefix = rIgnoreWhitespace + \
+                  r"(" + r"|".join(rCommentSymbols) + r")" + \
+                  rIgnoreWhitespace + \
+                  prefix + r":"
 
     # The 'match' function succeeds only if the pattern is matched at the
     # beginning of the line.
-    match = re.match(prefixRegex, line)
+    match = re.match(regexPrefix, line)
     if match is not None:
       return line[match.end():].strip()
     else: