[Bug rtl-optimization/61702] New: thumb1_reorg crashes

["manjian2006 at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61702

            Bug ID: 61702
           Summary: thumb1_reorg crashes
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: blocker
          Priority: P3
         Component: rtl-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: manjian2006 at gmail dot com

Compiling the attached source will result in the crash.
arm-linux-androideabi-g++ -c -fpic -ffunction-sections -funwind-tables
-fstack-protector -Wno-psabi -march=armv5te -mtune=xscale -msoft-float
-fno-exceptions -fno-rtti -mthumb -fomit-frame-pointer -fno-strict-aliasing
-finline-limit=64 -gdwarf-2 -funwind-tables -fno-pic -fPIC -fno-stack-protector
-fvisibility=hidden -gdwarf-2 -funwind-tables -fno-pic -fPIC
-fno-stack-protector -fvisibility=hidden -fvisibility-inlines-hidden
-Wa,--noexecstack -O0 -g -Wreturn-type -Wuninitialized  /tmp/1.cpp

/media/linzj/normal/home/linzj/src/u3/shell-git/core/WebCore/bindings/v8/V8DOMWrapper.h:
In static member function 'static v8::Handle<v8::Object>
WebCore::V8DOMWrapper::getWrapper(WebCore::Node*)':
/media/linzj/normal/home/linzj/src/u3/shell-git/core/WebCore/bindings/v8/V8DOMWrapper.h:136:9:
internal compiler error: Segmentation fault
         }
         ^
0x94564f crash_signal
    ../../building/gcc/toplev.c:337
0xb523a8 thumb1_reorg
    ../../building/gcc/config/arm/arm.c:16728
0xb523a8 arm_reorg
    ../../building/gcc/config/arm/arm.c:16981
0x8fc039 rest_of_handle_machine_reorg
    ../../building/gcc/reorg.c:3936
0x8fc039 execute
    ../../building/gcc/reorg.c:3966
Please submit a full bug report,



As far as I debug, I find out:
      /* Find the last cbranchsi4_insn in basic block BB.  */
      if (INSN_CODE (insn) != CODE_FOR_cbranchsi4_insn)
    continue;

      /* Get the register with which we are comparing.  */
=>      pat = PATTERN (insn);
      op0 = XEXP (XEXP (SET_SRC (pat), 0), 0);

pat is NULL.