Bug 42993 - [4.5 Regression] simplify-rtx.c:244: Conditional jump or move depends on uninitialised value(s)
Summary: [4.5 Regression] simplify-rtx.c:244: Conditional jump or move depends on unin...
Status: RESOLVED DUPLICATE of bug 42991
Alias: None
Product: gcc
Classification: Unclassified
Component: middle-end (show other bugs)
Version: 4.5.0
: P3 normal
Target Milestone: 4.5.0
Assignee: Not yet assigned to anyone
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2010-02-07 14:31 UTC by David Binderman
Modified: 2010-02-07 18:13 UTC (History)
2 users (show)

See Also:
Host: x86_64-suse-linux
Target:
Build:
Known to work:
Known to fail:
Last reconfirmed:

Attachments
C (150.56 KB, text/plain)
2010-02-07 14:33 UTC, David Binderman 		Details
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Description David Binderman 2010-02-07 14:31:55 UTC 
I just tried to compile the Linux kernel 2.6.33-rc6 under valgrind
with the C compiler version 4.5 snapshot 20100128 and valgrind said

==2968== Conditional jump or move depends on uninitialised value(s)
==2968==    at 0x7A6925: delegitimize_mem_from_attrs (simplify-rtx.c:244)
==2968==    by 0x961517: ix86_delegitimize_address (i386.c:10883)
==2968==    by 0x93E5F6: emit_note_insn_var_location (var-tracking.c:6515)
==2968==    by 0xCB84D7: htab_traverse_noresize (hashtab.c:753)
==2968==    by 0x941376: emit_notes_for_changes (var-tracking.c:6741)
==2968==    by 0x946A67: vt_emit_notes (var-tracking.c:7106)
==2968==    by 0x94A602: variable_tracking_main (var-tracking.c:7637)
==2968==    by 0x722ECA: execute_one_pass (passes.c:1561)
==2968==    by 0x723154: execute_pass_list (passes.c:1616)
==2968==    by 0x723166: execute_pass_list (passes.c:1617)
==2968==    by 0x723166: execute_pass_list (passes.c:1617)
==2968==    by 0x818C94: tree_rest_of_compilation (tree-optimize.c:413)
==2968==

Line 244 of simplify-rtx.c is

            if (bitsize != GET_MODE_BITSIZE (mode)
                || (bitpos % BITS_PER_UNIT)
                || (toffset && !host_integerp (toffset, 0)))
              decl = NULL;

Preprocessed source code attached. Flags -Os -g required.
Comment 1 David Binderman 2010-02-07 14:33:34 UTC 
Created attachment 19818 [details]
C
Comment 2 Richard Biener 2010-02-07 14:47:08 UTC 
Probably the same issue as PR42991.
Comment 3 Richard Biener 2010-02-07 15:29:02 UTC 
The fix for 42991 also fixes this bug.

*** This bug has been marked as a duplicate of 42991 ***
Comment 4 David Binderman 2010-02-07 18:13:34 UTC 
(In reply to comment #2)
> Probably the same issue as PR42991.

Does fixing 42991 also fix this problem ?

I suspect it might be worth checking this.