[Bug target/26636] New: use of r1-r3 across __sdivsi3_4 call

["rmansfield at qnx dot com" <gcc-bugzilla@gcc.gnu.org>]

[rmansfield@bender rmansfield]$
/home/rmansfield/crosstool/gcc-4.0-20060309-glibc-2.3.6/sh4-unknown-linux-gnu/bin/sh4-unknown-linux-gnu-gcc
-v -o t.s -S -m4 -O2 t.c
Using built-in specs.
Target: sh4-unknown-linux-gnu
Configured with:
/home/rmansfield/crosstool-0.42/build/sh4-unknown-linux-gnu/gcc-4.0-20060309-glibc-2.3.6/gcc-4.0-20060309/configure
--target=sh4-unknown-linux-gnu --host=i686-host_pc-linux-gnu
--prefix=/home/rmansfield/crosstool/gcc-4.0-20060309-glibc-2.3.6/sh4-unknown-linux-gnu
--with-multilib-list=m4,m4-nofpu
--with-headers=/home/rmansfield/crosstool/gcc-4.0-20060309-glibc-2.3.6/sh4-unknown-linux-gnu/sh4-unknown-linux-gnu/include
--with-local-prefix=/home/rmansfield/crosstool/gcc-4.0-20060309-glibc-2.3.6/sh4-unknown-linux-gnu/sh4-unknown-linux-gnu
--disable-nls --enable-threads=posix --enable-symvers=gnu --enable-__cxa_atexit
--enable-languages=c --enable-shared --enable-c99 --enable-long-long
Thread model: posix
gcc version 4.0.3


        mov.l   .L66,r0
        mov     r11,r1
        mov.w   .L65,r12
        add     #64,r1          ; use here
        mov     r3,r8
        mov     #30,r13
        jsr     @r0             ; call to __sdivsi3_4
        nop
        sts     fpul,r2
        add     #-124,r8
        mov     #120,r0
        add     r3,r12
        mov.l   r0,@(8,r14)
        mov     #31,r7
        mov.l   r2,@(56,r1)     ; kaboom

...

.L66:
        .long   __sdivsi3_i4


Then in the plt stub r1 gets clobbered.

0x804041c <_sdivsi3_i4>:        mov.l   0x8040424 <_sdivsi3_i4+8>,r1    !
0x80418a0
0x804041e <_sdivsi3_i4+2>:      mov.l   @r1,r1
0x8040420 <_sdivsi3_i4+4>:      jmp     @r1

/home/rmansfield/crosstool/gcc-4.1.0-glibc-2.3.6/sh4-unknown-linux-gnu/bin/sh4-unknown-linux-gnu-gcc
-v -o t.s -S -m4 -O2 t.c 
Using built-in specs.
Target: sh4-unknown-linux-gnu
Configured with:
/home/rmansfield/crosstool-0.42/build/sh4-unknown-linux-gnu/gcc-4.1.0-glibc-2.3.6/gcc-4.1.0/configure
--target=sh4-unknown-linux-gnu --host=i686-host_pc-linux-gnu
--prefix=/home/rmansfield/crosstool/gcc-4.1.0-glibc-2.3.6/sh4-unknown-linux-gnu
--with-multilib-list=m4,m4-nofpu
--with-headers=/home/rmansfield/crosstool/gcc-4.1.0-glibc-2.3.6/sh4-unknown-linux-gnu/sh4-unknown-linux-gnu/include
--with-local-prefix=/home/rmansfield/crosstool/gcc-4.1.0-glibc-2.3.6/sh4-unknown-linux-gnu/sh4-unknown-linux-gnu
--disable-nls --enable-threads=posix --enable-symvers=gnu --enable-__cxa_atexit
--enable-languages=c --enable-shared --enable-c99 --enable-long-long
Thread model: posix
gcc version 4.1.0


gcc 4.1 generates the following code:

        mov.l   .L57,r0
        jsr     @r0
        nop
        sts     fpul,r4
.L8:
        mov.w   .L55,r8
        mov     r9,r1
        mov.w   .L56,r12
        add     #64,r1
        add     r10,r8
        mov.l   r4,@(56,r1)

...
.L57:
        .long   __sdivsi3_i4


I think this hasn't been previously observed because the .hidden directive in
lib1funcs.asm makes each shared library get its own private __sdivsi3_i4 that
it can call directly and no registers end up being clobbered. But shouldn't
(clobber (reg:SI R1_REG)) in 
"divsi3" prevent the use of R1-R3 across the __sdivsi3 call?


-- 
           Summary: use of r1-r3 across __sdivsi3_4 call
           Product: gcc
           Version: 4.0.3
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: rmansfield at qnx dot com
 GCC build triplet: i686-host_pc-linux-gnu
  GCC host triplet: i686-host_pc-linux-gnu
GCC target triplet: sh4-unknown-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26636