[Bug optimization/14119] New: libjava Array_3 test fails at -O1

["amodra at bigpond dot net dot au" <gcc-bugzilla at gcc dot gnu dot org>]

I've been working on the hammer branch, and noticed the libjava Array_3 test
failing there but passing on mainline.  After looking in vain for the patch that
cured the problem on mainline, I realized the pass on mainline was because the
test has changed.  Mainline runs libjava tests at -O0 and -O3, hammer-3_3-branch
runs them at -O0 and -O1.  Running mainline (and gcc-3.4) tests at -O1 exhibits
the same failure:

LD_LIBRARY_PATH=../.libs:../../../gcc ./Array_3.exe
Exception in thread "main" java.lang.RuntimeException: test failed:4
[snip rest of output]

This appears to be a combine problem.

Array_3.java.19.life:

(insn 216 215 220 30
/src/gcc-current/libjava/testsuite/libjava.lang/Array_3.java:66 (set (reg/v:DI
119 [ ok ])
        (const_int 0 [0x0])) 324 {*movdi_internal64} (nil)
    (nil))

(note 220 216 222 30
("/src/gcc-current/libjava/testsuite/libjava.lang/Array_3.java") 69)

(note 222 220 225 30
("/src/gcc-current/libjava/testsuite/libjava.lang/Array_3.java") 70)

(insn 225 222 363 30
/src/gcc-current/libjava/testsuite/libjava.lang/Array_3.java:70 (set:DI (reg:DI
164 [ <variable>.length ])
        (zero_extend:DI (mem/s/j:SI (plus:DI (reg/v:DI 119 [ ok ])
                    (const_int 8 [0x8])) [0 <variable>.length+0 S4 A64]))) 12
{*rs6000.md:372} (insn_list 216 (nil))
    (expr_list:REG_UNUSED (reg:DI 164 [ <variable>.length ])
        (expr_list:REG_EH_REGION (const_int 7 [0x7])
            (nil))))


Array_3.java.20.combine:

(note 216 215 220 30 NOTE_INSN_DELETED)

(note 220 216 222 30
("/src/gcc-current/libjava/testsuite/libjava.lang/Array_3.java") 69)

(note 222 220 225 30
("/src/gcc-current/libjava/testsuite/libjava.lang/Array_3.java") 70)

(insn 225 222 421 30
/src/gcc-current/libjava/testsuite/libjava.lang/Array_3.java:70 (set (reg/v:DI
119 [ ok ])
        (const_int 0 [0x0])) 324 {*movdi_internal64} (nil)
    (nil))

-- 
           Summary: libjava Array_3 test fails at -O1
           Product: gcc
           Version: 3.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: amodra at bigpond dot net dot au
                CC: gcc-bugs at gcc dot gnu dot org
GCC target triplet: powerpc64-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14119