Fix a crash in OpenCL code by using the proper (RHS) bit-width.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@173802 91177308-0d34-0410-b5e6-96231b3b80d8

lib/AST/ExprConstant.cpp

@@ -4723,7 +4723,7 @@ bool DataRecursiveIntBinOpEvaluator::
     case BO_Shl: {
       if (Info.getLangOpts().OpenCL)
         // OpenCL 6.3j: shift values are effectively % word size of LHS.
-        RHS &= APSInt(llvm::APInt(LHS.getBitWidth(),
+        RHS &= APSInt(llvm::APInt(RHS.getBitWidth(),
                       static_cast<uint64_t>(LHS.getBitWidth() - 1)),
                       RHS.isUnsigned());
       else if (RHS.isSigned() && RHS.isNegative()) {
@@ -4755,7 +4755,7 @@ bool DataRecursiveIntBinOpEvaluator::
     case BO_Shr: {
       if (Info.getLangOpts().OpenCL)
         // OpenCL 6.3j: shift values are effectively % word size of LHS.
-        RHS &= APSInt(llvm::APInt(LHS.getBitWidth(),
+        RHS &= APSInt(llvm::APInt(RHS.getBitWidth(),
                       static_cast<uint64_t>(LHS.getBitWidth() - 1)),
                       RHS.isUnsigned());
       else if (RHS.isSigned() && RHS.isNegative()) {

test/SemaOpenCL/shifts.cl

@@ -2,13 +2,16 @@
 // OpenCL essentially reduces all shift amounts to the last word-size bits before evaluating.
 // Test this both for variables and constants evaluated in the front-end.
 
-//CHECK: @negativeShift32
+// CHECK: @gtest1 = constant i64 2147483648
+__constant const unsigned long gtest1 = 1UL << 31;
+
+// CHECK: @negativeShift32
 int negativeShift32(int a,int b) {
-  //CHECK: %array0 = alloca [256 x i8]
+  // CHECK: %array0 = alloca [256 x i8]
   char array0[((int)1)<<40];
-  //CHECK: %array1 = alloca [256 x i8]
+  // CHECK: %array1 = alloca [256 x i8]
   char array1[((int)1)<<(-24)];
 
-  //CHECK: ret i32 65536
+  // CHECK: ret i32 65536
   return ((int)1)<<(-16);
 }