gcc/testsuite/gcc.target/sh/pr51244-19.c

   1 /* Check that no unnecessary T bit stores are done before conditional
   2    branches.
   3    This case was extracted from the CSiBE set and contained the following
   4    sequence:
   5         mov.l   @(8,r4),r2
   6         mov.l   @(4,r4),r3
   7         cmp/gt  r2,r3
   8         movt    r2
   9 .L3:
  10         tst     r2,r2
  11         bt/s    .L12
  12         mov     #-1,r0
  13
  14         .....
  15
  16         mov.l   @r4,r2
  17         tst     r2,r2
  18         bra     .L3
  19         movt    r2
  20
  21    In this reduced code the movt insns were only present in the
  22    unwanted sequences.  Thus, if we see any movt insns, something is not
  23    working as expected.  This test requires -O2 because the T bit stores
  24    in question will be eliminated in additional insn split passes after
  25    reload.  */
  26 /* { dg-do compile }  */
  27 /* { dg-options "-O2" } */
  28 /* { dg-final { scan-assembler-not "movt" } } */
  29
  30 struct request
  31 {
  32  unsigned long nr_sectors;
  33 };
  34
  35 struct request_list
  36 {
  37  int count;
  38 };
  39
  40 struct request_queue
  41 {
  42  struct request_list rq;
  43  volatile int nr_sectors;
  44  int max_queue_sectors;
  45  int can_throttle;
  46  unsigned long bounce_pfn;
  47 };
  48
  49 typedef struct request_queue request_queue_t;
  50
  51 static inline int
  52 blk_oversized_queue (request_queue_t* q)
  53 {
  54   if (q->can_throttle)
  55     return q->nr_sectors > q->max_queue_sectors;
  56   return q->rq.count == 0;
  57 }
  58
  59 struct request*
  60 get_request (request_queue_t* q, int rw)
  61 {
  62   struct request* rq = ((void*)0);
  63   struct request_list *rl = &q->rq;
  64
  65   if (blk_oversized_queue (q))
  66     {
  67       if ((rw == 1) || (rw == 0))
  68         return ((void*)0);
  69       if (blk_oversized_queue (q))
  70         return ((void*)0);
  71     }
  72
  73   return (void*)-100;
  74 }