[PATCH, i386, Pointer Bounds Checker 30/x] Size relocation

Ilya Enkovich enkovich.gnu@gmail.com
Tue Sep 16 09:37:00 GMT 2014


2014-09-16 13:08 GMT+04:00 Uros Bizjak <ubizjak@gmail.com>:
> Hello!
>
>> This patch adds size relocation support for i386 target.  Relocation is used to compute bounds for static objects with incomplete type.
>>
>> Thanks,
>> Ilya
>> --
>> gcc/
>>
>> 2014-06-11  Ilya Enkovich  <ilya.enkovich@intel.com>
>>
>>         * config/i386/i386.md (UNSPEC_SIZEOF): New.
>>         (move_size_reloc_si): New.
>>         (move_size_reloc_di): New.
>>         * config/i386/predicates.md (symbol_operand): New.
>>
>>
>> diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
>> index 32db2c6..5fd556b 100644
>> --- a/gcc/config/i386/i386.md
>> +++ b/gcc/config/i386/i386.md
>> @@ -79,6 +79,7 @@
>>    UNSPEC_PLTOFF
>>    UNSPEC_MACHOPIC_OFFSET
>>    UNSPEC_PCREL
>> +  UNSPEC_SIZEOF
>>
>>    ;; Prologue support
>>    UNSPEC_STACK_ALLOC
>> @@ -18340,6 +18341,32 @@
>>    "bndstx\t{%2, %3|%3, %2}"
>>    [(set_attr "type" "mpxst")])
>>
>> +(define_insn "move_size_reloc_si"
>> +  [(set (match_operand:SI 0 "register_operand" "=r")
>> +       (unspec:SI
>> +        [(match_operand:SI 1 "symbol_operand")]
>> +        UNSPEC_SIZEOF))]
>> +  "TARGET_MPX"
>> +  "mov{l}\t{%1@SIZE, %0|%0, %1@SIZE}"
>> +  [(set_attr "type" "imov")
>> +   (set_attr "mode" "SI")])
>> +
>> +(define_insn "move_size_reloc_di"
>> +  [(set (match_operand:DI 0 "register_operand" "=r")
>> +       (unspec:DI
>> +        [(match_operand:DI 1 "symbol_operand")]
>> +        UNSPEC_SIZEOF))]
>> +  "TARGET_64BIT && TARGET_MPX"
>> +{
>> +  if (ix86_cmodel == CM_MEDIUM || ix86_cmodel == CM_LARGE
>> +      || ix86_cmodel == CM_MEDIUM_PIC || ix86_cmodel == CM_LARGE_PIC)
>> +    return "movabs{q}\t{%1@SIZE, %0|%0, %1@SIZE}";
>
> Can x86_64_immediate_operand predicate be used here?

I think it cannot be used because of TLS symbols not counting as immediate.

Thanks,
Ilya

>
>> +  else
>> +    return "mov{l}\t{%1@SIZE, %k0|%k0, %1@SIZE}";
>> +}
>> +  [(set_attr "type" "imov")
>> +   (set_attr "mode" "DI")])
>> +
>>  (include "mmx.md")
>>  (include "sse.md")
>>  (include "sync.md")
>> diff --git a/gcc/config/i386/predicates.md b/gcc/config/i386/predicates.md
>> index a738033..e4c5d21 100644
>> --- a/gcc/config/i386/predicates.md
>> +++ b/gcc/config/i386/predicates.md
>> @@ -119,6 +119,10 @@
>>         (match_test "TARGET_64BIT")
>>         (match_test "REGNO (op) > BX_REG")))
>>
>> +;; Return true if VALUE is symbol reference
>> +(define_predicate "symbol_operand"
>> +  (match_code "symbol_ref"))
>> +
>>  ;; Return true if VALUE can be stored in a sign extended immediate field.
>>  (define_predicate "x86_64_immediate_operand"
>>    (match_code "const_int,symbol_ref,label_ref,const")
>
> Uros.



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