Volatile const members of a struct are not generating a load when read while
volatile non-const members are loaded (volatile const objects outside of a
structure do generate a load when read). const members of a volatile struct
generate two loads when read (strange code being produced in this case). This
has been seen in 3.3.3 (for x86 and m68k targets) and 3.4.4 (for m68k targets,
untested on x86). The attached test.cpp file when compiled gcc -c -save-temps
test.cpp on 3.3.3 under cygwin (x86 target) produces the attached test.s
output. Multiple stores on volatile const members of structs get optimized
away as well (this is not demonstrated in the attached test code). Note that
when the test code is compiled as C rather than C++, correct code gets
produced.
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Summary: volatile const members of structures not treated as
volatile
Product: gcc
Version: 3.4.4
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: c++
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: Steve at Zook dot com
CC: gcc-bugs at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23702
