clang/test/Misc/backend-optimization-failure.cpp

   1 // RUN: %clang_cc1 -triple x86_64-unknown-unknown %s -O3 -emit-llvm -debug-info-kind=line-tables-only -S -verify -o /dev/null
   2 // REQUIRES: x86-registered-target
   3
   4 // Test verifies optimization failures generated by the backend are handled
   5 // correctly by clang. LLVM tests verify all of the failure conditions.
   6
   7 void test_switch(int *A, int *B, int Length,int J) {
   8 #pragma clang loop vectorize(enable) unroll(disable)
   9   for (int i = 0; i < Length; i++) {
  10 /* expected-warning@-1 {{loop not vectorized: the optimizer was unable to perform the requested transformation; the transformation might be disabled or specified as part of an unsupported transformation ordering}} */ switch (A[i]) {
  11     case 0:
  12       B[i] = 1;
  13       break;
  14     case 1:
  15       B[J] = 2;
  16       break;
  17     default:
  18       B[i] = 3;
  19     }
  20   }
  21 }