[Bug target/44490] New: X86 memory mismatch stall

[hjl dot tools at gmail dot com]

Since x86 zero extends when passing argument,
we get memory mismatch stall:

[...@gnu-6 899]$ cat call-1.c
short
__attribute__((noinline))
foo (short x, short y, short z)
{
   return x + y + z;
}

short
bar (short z, short x, short y)
{
  return foo (x, y, z);
}
[...@gnu-6 899]$ gcc -O2 -m32 call-1.c -S
[...@gnu-6 899]$ cat call-1.s
        .file   "call-1.c"
        .text
        .p2align 4,,15
.globl foo
        .type   foo, @function
foo:
        pushl   %ebp
        movl    %esp, %ebp
        movzwl  12(%ebp), %eax << 2bytes
        addw    8(%ebp), %ax
        addw    16(%ebp), %ax
        popl    %ebp
        ret
        .size   foo, .-foo
        .p2align 4,,15
.globl bar
        .type   bar, @function
bar:
        pushl   %ebp
        movl    %esp, %ebp
        movswl  12(%ebp), %eax
        movswl  16(%ebp), %edx
        movswl  8(%ebp), %ecx
        movl    %eax, 8(%ebp) << 4bytes
        movl    %edx, 12(%ebp)
        movl    %ecx, 16(%ebp)
        popl    %ebp
        jmp     foo


-- 
           Summary: X86 memory mismatch stall
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: hjl dot tools at gmail dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44490