[Bug target/32437] [4.3 Regression] MIPS: FAIL in gcc.dg/cleanup-[8|9|10|11].c

["daney at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org>]

------- Comment #4 from daney at gcc dot gnu dot org  2007-06-22 08:38 -------
Looking at the rtl dumps of unwind-dw2.c compiled with -O1 I find:

In unwind-dw2.c.135r.subreg (_Unwind_Resume):
.
.
.
(insn 72 71 73 6 ../../../trunk/libgcc/../gcc/unwind.inc:216 (parallel [
            (unspec [
                    (reg:SI 223)
                ] 7)
            (clobber (scratch:SI))
        ]) 349 {eh_set_lr_si} (nil))

.
.
.

And in unwind-dw2.c.137r.cse1 (_Unwind_Resume):
.
.
.
DCE: Deleting insn 72
deleting insn with uid = 72.
.
.
.

The insn eh_set_lr_si (see the patch) only clobbers a scratch register, and
since we cannot split it to say we set the return address until after reload, I
don't know how to keep it from being deleted unless we say it is volatile.

I am a bit surprised that the very first thing I tried worked, but after more
thought I cannot come up with anything else.

The patch fixes all c++ and libstdc++ testsuite regressions caused by the
dateflow merge (on mipsel-linux), so I would like to commit it.

Thoughts?


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32437