[Bug c/48385] New: x86-64: Tail call recursion optimization with -mcmodel=large can generate invalid assembly (immediate operand illegal with absolute jump)

["martin at decky dot cz" <gcc-bugzilla@gcc.gnu.org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48385

           Summary: x86-64: Tail call recursion optimization with
                    -mcmodel=large can generate invalid assembly
                    (immediate operand illegal with absolute jump)
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: major
          Priority: P3
         Component: c
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: martin@decky.cz


Created attachment 23836
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=23836
Compiler result using -save-temps

When using -mcmodel=large and -O3, a tail call to an extern function can
generate an invalid assembly like in the following example:

    jmp *$memsetb

The correct assembly output should be perhaps:

    jmp *memsetb

The problem can be worked around by adding the "-fno-optimize-sibling-calls"
option to the compiler command line.


Output of /usr/local/cross/amd64/bin/amd64-linux-gnu-gcc -v:

Using built-in specs.
COLLECT_GCC=/usr/local/cross/amd64/bin/amd64-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/usr/local/cross/amd64/libexec/gcc/amd64-linux-gnu/4.6.0/lto-wrapper
Target: amd64-linux-gnu
Configured with: /root/install/cross/amd64/gcc-4.6.0/configure
--target=amd64-linux-gnu --prefix=/usr/local/cross/amd64
--program-prefix=amd64-linux-gnu- --with-gnu-as --with-gnu-ld --disable-nls
--disable-threads --enable-languages=c,objc,c++,obj-c++ --disable-multilib
--disable-libgcj --without-headers --disable-shared --enable-lto
Thread model: single
gcc version 4.6.0 (GCC)


Command line that triggered the bug:

/usr/local/cross/amd64/bin/amd64-linux-gnu-gcc -DKERNEL -DRELEASE=0.4.3
"-DNAME=Sashimi" -D__64_BITS__ -D__LE__ -Igeneric/include -O3 -imacros
../config.h -fexec-charset=UTF-8 -fwide-exec-charset=UTF-32LE
-finput-charset=UTF-8 -ffreestanding -fno-builtin -nostdlib -nostdinc -Wall
-Wextra -Wno-unused-parameter -Wmissing-prototypes
-Werror-implicit-function-declaration -Wwrite-strings -pipe -Werror -m64
-mcmodel=large -mno-red-zone -fno-unwind-tables -fno-omit-frame-pointer
-march=opteron -Itest/  -mno-sse -mno-sse2  -c -o genarch/src/mm/page_pt.o
genarch/src/mm/page_pt.c


Compiler output:

{standard input}: Assembler messages:
{standard input}:722: Error: immediate operand illegal with absolute jump