Apply most suggestions of clang-tidy's performance-unnecessary-value-param

Avoids unnecessary copies. All changes audited & pass tests with asan.
No functional change intended.

llvm-svn: 272190
diff --git a/llvm/lib/Analysis/DependenceAnalysis.cpp b/llvm/lib/Analysis/DependenceAnalysis.cpp
index 3342bdf..796c872 100644
--- a/llvm/lib/Analysis/DependenceAnalysis.cpp
+++ b/llvm/lib/Analysis/DependenceAnalysis.cpp
@@ -1326,9 +1326,8 @@
 // Computes the GCD of AM and BM.
 // Also finds a solution to the equation ax - by = gcd(a, b).
 // Returns true if dependence disproved; i.e., gcd does not divide Delta.
-static
-bool findGCD(unsigned Bits, APInt AM, APInt BM, APInt Delta,
-             APInt &G, APInt &X, APInt &Y) {
+static bool findGCD(unsigned Bits, const APInt &AM, const APInt &BM,
+                    const APInt &Delta, APInt &G, APInt &X, APInt &Y) {
   APInt A0(Bits, 1, true), A1(Bits, 0, true);
   APInt B0(Bits, 0, true), B1(Bits, 1, true);
   APInt G0 = AM.abs();
@@ -1357,9 +1356,7 @@
   return false;
 }
 
-
-static
-APInt floorOfQuotient(APInt A, APInt B) {
+static APInt floorOfQuotient(const APInt &A, const APInt &B) {
   APInt Q = A; // these need to be initialized
   APInt R = A;
   APInt::sdivrem(A, B, Q, R);
@@ -1372,9 +1369,7 @@
     return Q - 1;
 }
 
-
-static
-APInt ceilingOfQuotient(APInt A, APInt B) {
+static APInt ceilingOfQuotient(const APInt &A, const APInt &B) {
   APInt Q = A; // these need to be initialized
   APInt R = A;
   APInt::sdivrem(A, B, Q, R);