Hello,
this small tweak of fold_real_zero_addition_p lets it handle vectors as
well.
Bootstrap and regtest on x86_64-pc-linux-gnu.
2019-06-10 Marc Glisse <marc.gli...@inria.fr>
PR tree-optimization/62041
* fold-const.c (fold_real_zero_addition_p): Handle vectors.
--
Marc GlisseIndex: gcc/fold-const.c
===================================================================
--- gcc/fold-const.c (revision 272076)
+++ gcc/fold-const.c (working copy)
@@ -6715,40 +6715,45 @@ fold_binary_op_with_conditional_arg (loc
X - 0 is not the same as X because 0 - 0 is -0. In other rounding
modes, X + 0 is not the same as X because -0 + 0 is 0. */
bool
fold_real_zero_addition_p (const_tree type, const_tree addend, int negate)
{
if (!real_zerop (addend))
return false;
/* Don't allow the fold with -fsignaling-nans. */
- if (HONOR_SNANS (element_mode (type)))
+ if (HONOR_SNANS (type))
return false;
/* Allow the fold if zeros aren't signed, or their sign isn't important. */
- if (!HONOR_SIGNED_ZEROS (element_mode (type)))
+ if (!HONOR_SIGNED_ZEROS (type))
return true;
+ /* There is no case that is safe for all rounding modes. */
+ if (HONOR_SIGN_DEPENDENT_ROUNDING (type))
+ return false;
+
/* In a vector or complex, we would need to check the sign of all zeros. */
- if (TREE_CODE (addend) != REAL_CST)
+ if (TREE_CODE (addend) == VECTOR_CST)
+ addend = uniform_vector_p (addend);
+ if (!addend || TREE_CODE (addend) != REAL_CST)
return false;
/* Treat x + -0 as x - 0 and x - -0 as x + 0. */
if (REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
negate = !negate;
/* The mode has signed zeros, and we have to honor their sign.
In this situation, there is only one case we can return true for.
- X - 0 is the same as X unless rounding towards -infinity is
- supported. */
- return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (element_mode (type));
+ X - 0 is the same as X with default rounding. */
+ return negate;
}
/* Subroutine of match.pd that optimizes comparisons of a division by
a nonzero integer constant against an integer constant, i.e.
X/C1 op C2.
CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
GE_EXPR or LE_EXPR. ARG01 and ARG1 must be a INTEGER_CST. */
enum tree_code
