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fold_real_zero_addition_p for vectors

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2019-06-11  Marc Glisse  <marc.glisse@inria.fr>

	PR tree-optimization/62041
	* fold-const.c (fold_real_zero_addition_p): Handle vectors.

From-SVN: r272151
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Marc Glisse 2019-06-11 14:48:26 +02:00 • committed by Marc Glisse
parent 9281275764
commit 7ac9a20184
2 changed files with 16 additions and 6 deletions
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5
gcc/ChangeLog
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@ -1,3 +1,8 @@
2019-06-11 Marc Glisse <marc.glisse@inria.fr>
PR tree-optimization/62041
* fold-const.c (fold_real_zero_addition_p): Handle vectors.
2019-06-11 Jason Merrill <jason@redhat.com>
* gdbhooks.py (TreePrinter.to_string): Recognize ggc_free'd memory.

17
gcc/fold-const.c
View file

@ -6722,15 +6722,21 @@ fold_real_zero_addition_p (const_tree type, const_tree addend, int negate)
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. */
@ -6739,9 +6745,8 @@ fold_real_zero_addition_p (const_tree type, const_tree addend, int 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