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 /* { dg-require-effective-target int32plus } */
   5
   6 extern void abort (void);
   7
   8 #define NOINLINE __attribute__((noinline))
   9
  10 static NOINLINE int
  11 f1 (int n)
  12 {
  13   return n / 33;
  14 }
  15
  16 static NOINLINE int
  17 f2 (int n)
  18 {
  19   return n / 77;
  20 }
  21
  22 int
  23 main ()
  24 {
  25   int a = 0xaaaaaaaa;
  26   int b = 0x55555555;
  27   int c;
  28   c = f1 (a);
  29   if (c != 0xfd6a052c)
  30     abort ();
  31   c = f1 (b);
  32   if (c != 0x295FAD4)
  33     abort ();
  34   c = f2 (a);
  35   if (c != 0xfee44b5c)
  36     abort ();
  37   c = f2 (b);
  38   if (c != 0x11bb4a4)
  39     abort ();
  40   return 0;
  41 }
  42
  43 /* Following replacement pattern of intger division by constant, GCC is expected
  44    to generate MULT and (x)SHIFTRT.  This test checks that considering division
  45    by const 33, gcc generates a single ASHIFTRT by 35, instead of two - LSHIFTRT
  46    by 32 and ASHIFTRT by 3.  */
  47
  48 /* { dg-final { scan-rtl-dump "\\(set \\(subreg:DI \\(reg:SI" "combine" { target aarch64*-*-* } } } */
  49 /* { dg-final { scan-rtl-dump "\\(ashiftrt:DI \\(reg:DI" "combine" { target aarch64*-*-* } } } */
  50 /* { dg-final { scan-rtl-dump "\\(const_int 35 " "combine" { target aarch64*-*-* } } } */
  51
  52 /* Similarly, considering division by const 77, gcc generates a single ASHIFTRT
  53    by 36, instead of two - LSHIFTRT by 32 and ASHIFTRT by 4.  */
  54
  55 /* { dg-final { scan-rtl-dump "\\(const_int 36 " "combine" { target aarch64*-*-* } } } */
  56