gcc/testsuite/gcc.dg/asr_div1.c

   1 /* Test division by const int generates only one shift.  */
   2 /* { dg-do run } */
   3 /* { dg-options "-O2 -fdump-rtl-combine-all" } */
   4
   5 extern void abort (void);
   6
   7 #define NOINLINE __attribute__((noinline))
   8
   9 static NOINLINE int
  10 f1 (int n)
  11 {
  12   return n / 33;
  13 }
  14
  15 static NOINLINE int
  16 f2 (int n)
  17 {
  18   return n / 77;
  19 }
  20
  21 int
  22 main ()
  23 {
  24   int a = 0xaaaaaaaa;
  25   int b = 0x55555555;
  26   int c;
  27   c = f1 (a);
  28   if (c != 0xfd6a052c)
  29     abort ();
  30   c = f1 (b);
  31   if (c != 0x295FAD4)
  32     abort ();
  33   c = f2 (a);
  34   if (c != 0xfee44b5c)
  35     abort ();
  36   c = f2 (b);
  37   if (c != 0x11bb4a4)
  38     abort ();
  39   return 0;
  40 }
  41
  42 /* Following replacement pattern of intger division by constant, GCC is expected
  43    to generate MULT and (x)SHIFTRT.  This test checks that considering division
  44    by const 33, gcc generates a single ASHIFTRT by 35, instead of two - LSHIFTRT
  45    by 32 and ASHIFTRT by 3.  */
  46
  47 /* { dg-final { scan-rtl-dump "\\(set \\(subreg:DI \\(reg:SI" "combine" { target aarch64*-*-* } } } */
  48 /* { dg-final { scan-rtl-dump "\\(ashiftrt:DI \\(reg:DI" "combine" { target aarch64*-*-* } } } */
  49 /* { dg-final { scan-rtl-dump "\\(const_int 35 " "combine" { target aarch64*-*-* } } } */
  50
  51 /* Similarly, considering division by const 77, gcc generates a single ASHIFTRT
  52    by 36, instead of two - LSHIFTRT by 32 and ASHIFTRT by 4.  */
  53
  54 /* { dg-final { scan-rtl-dump "\\(const_int 36 " "combine" { target aarch64*-*-* } } } */
  55
  56 /* { dg-final { cleanup-rtl-dump "combine" } } */