/* { dg-do compile } */ /* { dg-options "-O2 -fdump-tree-optimized" } */ /* PR tree-optimization/101590 */ /* These are the signed integer versions of `(a & b) CMP a` and `(a | b) CMP a` which can be optimized to 1. */ #if __SIZEOF_INT__ < 4 #define int __INT32_TYPE__ #endif /* For `&`, the non-negativeness of b is not taken into account. */ int f_and_le(int len) { len &= 0xfffff; const int N = 4; int newlen = len & -N; return newlen <= len; // return 1 } int f_and_le_(int len, int N) { len &= 0xfffff; int newlen = len & -N; return newlen <= len; // return 1 } /* For `|`, to get a known value, b either needs to be non-negative or a constant. For the negative constant case, we swap around the comparison. */ int f_or_ge_(int len, int N) { len &= 0xfffff; N &= 0xffff; int newlen = len | N; return newlen >= len; // return 1 } int f_or_lt(int len) { len &= 0xfffff; const int N = 4; int newlen = len | -N; return newlen < len; // return 1 } /* { dg-final { scan-tree-dump-not " <= " "optimized" } } */ /* { dg-final { scan-tree-dump-not " >= " "optimized" } } */ /* { dg-final { scan-tree-dump-not " & " "optimized" } } */ /* { dg-final { scan-tree-dump-not " \\\| " "optimized" } } */ /* { dg-final { scan-tree-dump-times "return 1;" 4 "optimized" } } */