[Bug c/12312] [3.4 regression] Bootstrap fails compiling unwind-dw2.c

[danglin at gcc dot gnu dot org]

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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12312


danglin at gcc dot gnu dot org changed:

           What    |Removed                     |Added
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                 CC|                            |roger at eyesopen dot com


------- Additional Comments From danglin at gcc dot gnu dot org  2003-09-17 19:37 -------
On the PA, the following patch introduced the regression:

2003-09-16  Roger Sayle  <roger@eyesopen.com>

        PR bootstrap/12269
        * simplify-rtx.c (simplify_gen_relational): Allow the cmp_mode
        argument to be VOIDmode, taking the mode of the comparison from
        the operands.  Only call simplify_relational_operation if we
        know the mode of the comparison.  Honor FLOAT_STORE_FLAG_VALUE
        if comparison has a floating point result.  Ensure that the
        result is always of the specified mode.
        (simplify_replace_rtx): Simplify call to simplify_gen_relational.
        (simplify_unary_operation): Ensure the correct mode and cmp_mode
        are always passed to simplify_gen_relational.  Simplify NOT of
        comparison operator in any mode, not just BImode.
        (simplify_ternary_operation): Correct tests on the return value
        of simplify_relational_operation to use const_true_rtx, not
        const1_rtx.  Abort if it ever returns a non-constant result.

        * cfgloopanal.c (count_strange_loop_iterations): Use the function
        simplify_relational_operation, not simplify_gen_relational, if
        we're only interested in constant comparisons and will ignore
        non-constant results.

The testcase is only miscompiled by the stage2 compiler.  Thus, it
doesn't show the bug directly.