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[Bug tree-optimization/22000] [4.0/4.1 Regression] Read from volatile member of struct is optimized away
- From: "mmitchel at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 23 Jun 2005 15:11:52 -0000
- Subject: [Bug tree-optimization/22000] [4.0/4.1 Regression] Read from volatile member of struct is optimized away
- References: <20050610135925.22000.rpedersen@atmel.com>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Additional Comments From mmitchel at gcc dot gnu dot org 2005-06-23 15:11 -------
I somewhat suspect this hunk of code in c-typeck.c:build_component_ref:
if (TREE_THIS_VOLATILE (datum) || TREE_THIS_VOLATILE (subdatum))
TREE_THIS_VOLATILE (ref) = 1;
I don't see anything that sets TREE_SIDE_EFFECTS.
However, from tree.h:
If this bit is set in an expression, so is TREE_SIDE_EFFECTS. */
#define TREE_THIS_VOLATILE(NODE) ((NODE)->common.volatile_flag)
However, I'm having a hard time getting good connectivity back to my build
machine to experiment with this.
Joseph, any ideas about this?
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What |Removed |Added
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CC| |joseph at codesourcery dot
| |com
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22000