[Bug target/54457] New: [x32] Fail to combine 64bit index + constant

[hjl.tools at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54457

             Bug #: 54457
           Summary: [x32] Fail to combine 64bit index + constant
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
        AssignedTo: unassig...@gcc.gnu.org
        ReportedBy: hjl.to...@gmail.com
                CC: ubiz...@gmail.com


[hjl@gnu-ivb-1 pr54445]$ cat z.i
extern char array[40];

char
foo (long long int position) {
  return array[position + 1];
}
[hjl@gnu-ivb-1 pr54445]$
/export/build/gnu/gcc-x32/build-x86_64-linux/prev-gcc/xgcc
-B/export/build/gnu/gcc-x32/build-x86_64-linux/prev-gcc/ -Wall -O2 -std=gnu11
-mx32 -S z.i -da
[hjl@gnu-ivb-1 pr54445]$ cat z.s
    .file    "z.i"
    .text
    .p2align 4,,15
    .globl    foo
    .type    foo, @function
foo:
.LFB0:
    .cfi_startproc
    addq    $1, %rdi
    movzbl    array(%edi), %eax
    ret
    .cfi_endproc
.LFE0:
    .size    foo, .-foo
    .ident    "GCC: (GNU) 4.8.0 20120901 (experimental)"
    .section    .note.GNU-stack,"",@progbits
[hjl@gnu-ivb-1 pr54445]$ 

combine fails on:

Trying 6 -> 8:
Failed to match this instruction:
(set (reg:QI 66)
    (mem/j:QI (plus:SI (subreg:SI (plus:DI (reg/v:DI 62 [ position ])
                    (const_int 1 [0x1])) 0)
            (symbol_ref:SI ("array") [flags 0x40]  <var_decl 0x7ffff19ad260
arra
y>)) [0 array S1 A8]))

This should be a valid address.