[Bug middle-end/36194] [4.2/4.3 Regression] Truncation optimization in combine can remove necessary truncations

[nemet at gcc dot gnu dot org]

------- Comment #5 from nemet at gcc dot gnu dot org  2008-05-19 23:30 -------
Subject: Bug 36194

Author: nemet
Date: Mon May 19 23:29:29 2008
New Revision: 135592

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=135592
Log:
        PR middle-end/36194
        * combine.c (check_conversion): Rename to check_promoted_subreg. 
        Don't call record_truncated_value from here. 
        (record_truncated_value): Turn it into a for_each_rtx callback. 
        (record_truncated_values): New function. 
        (combine_instructions): Call note_uses with 
        record_truncated_values.  Change name of check_conversion to 
        check_promoted_subreg. 

testsuite/

        * gcc.dg/pr36194.c: New test.

Added:
    branches/gcc-4_3-branch/gcc/testsuite/gcc.dg/pr36194.c
Modified:
    branches/gcc-4_3-branch/gcc/ChangeLog
    branches/gcc-4_3-branch/gcc/combine.c
    branches/gcc-4_3-branch/gcc/testsuite/ChangeLog


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36194