diff options
Diffstat (limited to 'gcc/builtins.c')
| -rw-r--r-- | gcc/builtins.c | 31 |
1 files changed, 24 insertions, 7 deletions
diff --git a/gcc/builtins.c b/gcc/builtins.c index 5b9a87f..b7ce1e4 100644 --- a/gcc/builtins.c +++ b/gcc/builtins.c @@ -7143,13 +7143,30 @@ fold_builtin_cabs (tree arglist, tree type, tree fndecl) type, mpfr_hypot))) return res; - /* If either part is zero, cabs is fabs of the other. */ - if (TREE_CODE (arg) == COMPLEX_EXPR - && real_zerop (TREE_OPERAND (arg, 0))) - return fold_build1 (ABS_EXPR, type, TREE_OPERAND (arg, 1)); - if (TREE_CODE (arg) == COMPLEX_EXPR - && real_zerop (TREE_OPERAND (arg, 1))) - return fold_build1 (ABS_EXPR, type, TREE_OPERAND (arg, 0)); + if (TREE_CODE (arg) == COMPLEX_EXPR) + { + tree real = TREE_OPERAND (arg, 0); + tree imag = TREE_OPERAND (arg, 1); + + /* If either part is zero, cabs is fabs of the other. */ + if (real_zerop (real)) + return fold_build1 (ABS_EXPR, type, imag); + if (real_zerop (imag)) + return fold_build1 (ABS_EXPR, type, real); + + /* cabs(x+xi) -> fabs(x)*sqrt(2). */ + if (flag_unsafe_math_optimizations + && operand_equal_p (real, imag, OEP_PURE_SAME)) + { + REAL_VALUE_TYPE sqrt2; + + real_sqrt (&sqrt2, TYPE_MODE (type), &dconst2); + STRIP_NOPS (real); + return fold_build2 (MULT_EXPR, type, + fold_build1 (ABS_EXPR, type, real), + build_real (type, sqrt2)); + } + } /* Optimize cabs(-z) and cabs(conj(z)) as cabs(z). */ if (TREE_CODE (arg) == NEGATE_EXPR |