clang/test/CodeGen/bitfield-assign.c

   1 /* Check that the result of a bitfield assignment is properly
   2    truncated and does not generate a redundant load. */
   3
   4 /* Check that we get one load for each simple assign and two for the
   5    compound assign (load the old value before the add then load again
   6    to store back). Also check that our g0 pattern is good. */
   7 // RUN: %clang_cc1 -triple i386-unknown-unknown -emit-llvm -o %t %s
   8 // RUN: grep 'load ' %t | count 5
   9 // RUN: grep "@g0" %t | count 4
  10
  11 // Check that we got the right value.
  12 // RUN: %clang_cc1 -triple i386-unknown-unknown -O3 -emit-llvm -o %t %s
  13 // RUN: not grep 'load ' %t
  14 // RUN: not grep "@g0" %t
  15
  16 struct s0 {
  17   int f0 : 2;
  18   _Bool f1 : 1;
  19   unsigned f2 : 2;
  20 };
  21
  22 int g0(void);
  23
  24 void f0(void) {
  25   struct s0 s;
  26   if ((s.f0 = 3) != -1) g0();
  27 }
  28
  29 void f1(void) {
  30   struct s0 s;
  31   if ((s.f1 = 3) != 1) g0();
  32 }
  33
  34 void f2(void) {
  35   struct s0 s;
  36   if ((s.f2 = 3) != 3) g0();
  37 }
  38
  39 void f3(void) {
  40   struct s0 s;
  41   // Just check this one for load counts.
  42   s.f0 += 3;
  43 }
  44