[Bug tree-optimization/56139] New: unmodified static data could go in .rodata, not .data

[amker.cheng at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56139

             Bug #: 56139
           Summary: unmodified static data could go in .rodata, not .data
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: amker.cheng@gmail.com


For below program:

static int x[] = {1, 2, 3, 4};

void bar (int x);
int func(int i)
{
    int * const p = (int * const)&x;
    bar(p[i]);

    return 0;
}

build with:
arm-none-eabi-gcc -mthumb -mcpu=cortex-m0 -Os ...

The generated assembly code is:
    .text
    .align    1
    .global    func
    .code    16
    .thumb_func
    .type    func, %function
func:
    push    {r3, lr}
    ldr    r3, .L2
    lsl    r0, r0, #2
    ldr    r0, [r0, r3]
    bl    bar
    @ sp needed for prologue
    mov    r0, #0
    pop    {r3, pc}
.L3:
    .align    2
.L2:
    .word    .LANCHOR0
    .size    func, .-func
    .data
    .align    2
    .set    .LANCHOR0,. + 0
    .type    x, %object
    .size    x, 16
x:
    .word    1
    .word    2
    .word    3
    .word    4

while GCC 4.6 puts x in .rodata.