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Tighten tree-ssa-ccp.c:get_value_for_expr condition

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bit_value_unop and bit_value_binop require constant values
to be INTEGER_CSTs:

  gcc_assert ((rval.lattice_val == CONSTANT
               && TREE_CODE (rval.value) == INTEGER_CST)
              || wi::sext (rval.mask, TYPE_PRECISION (TREE_TYPE (rhs))) == -1);

However, when deciding whether to record a constant value,
the for_bits_p handling in get_value_for_expr used a negative
test for ADDR_EXPR:

  else if (is_gimple_min_invariant (expr)
           && (!for_bits_p || TREE_CODE (expr) != ADDR_EXPR))

This patch uses a positive test for INTEGER_CST instead.

Existing tests showed the need for this once polynomial constants
are added.

2017-09-21  Richard Sandiford  <richard.sandiford@linaro.org>
	    Alan Hayward  <alan.hayward@arm.com>
	    David Sherwood  <david.sherwood@arm.com>

gcc/
	* tree-ssa-ccp.c (get_value_for_expr): Use a positive test for
	INTEGER_CST rather than a negative test for ADDR_EXPR.

Co-Authored-By: Alan Hayward <alan.hayward@arm.com>
Co-Authored-By: David Sherwood <david.sherwood@arm.com>

From-SVN: r253056
This commit is contained in:
Richard Sandiford 2017-09-21 11:00:43 +00:00 committed by Richard Sandiford
parent dd72b5f952
commit 4a77e88747
2 changed files with 8 additions and 1 deletions
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7
gcc/ChangeLog
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@ -1,3 +1,10 @@
2017-09-21 Richard Sandiford <richard.sandiford@linaro.org>
Alan Hayward <alan.hayward@arm.com>
David Sherwood <david.sherwood@arm.com>
* tree-ssa-ccp.c (get_value_for_expr): Use a positive test for
INTEGER_CST rather than a negative test for ADDR_EXPR.
2017-09-21 Richard Sandiford <richard.sandiford@linaro.org>
Alan Hayward <alan.hayward@arm.com>
David Sherwood <david.sherwood@arm.com>

2
gcc/tree-ssa-ccp.c
View File

@ -617,7 +617,7 @@ get_value_for_expr (tree expr, bool for_bits_p)
}
}
else if (is_gimple_min_invariant (expr)
&& (!for_bits_p || TREE_CODE (expr) != ADDR_EXPR))
&& (!for_bits_p || TREE_CODE (expr) == INTEGER_CST))
{
val.lattice_val = CONSTANT;
val.value = expr;