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


On 01 Oct 19:57, Uros Bizjak wrote:
> On Wed, Oct 1, 2014 at 7:02 PM, Ilya Enkovich <enkovich.gnu@gmail.com> wrote:
> > 2014-10-01 19:17 GMT+04:00 Uros Bizjak <ubizjak@gmail.com>:
> >> On Wed, Oct 1, 2014 at 4:10 PM, Ilya Enkovich <enkovich.gnu@gmail.com> wrote:
> >>
> >>>> +;; Return true if size of VALUE can be stored in a sign
> >>>> +;; extended immediate field.
> >>>> +(define_predicate "x86_64_immediate_size_operand"
> >>>> +  (match_code "symbol_ref")
> >>>> +{
> >>>> +  if (!TARGET_64BIT)
> >>>> +    return true;
> >>>> +
> >>>> +  /* For 64 bit target we may assume size of object fits
> >>>> +     immediate only when code model guarantees that.  */
> >>>> +  return (ix86_cmodel == CM_SMALL || ix86_cmodel == CM_KERNEL);
> >>>> +})
> >>>> +
> >>>
> >>> This predicate causes bootstrap error:
> >>> predicates.md:362:38: error: unused parameter 'op' [-Werror=unused-parameter]
> >>
> >> Huh? How is this predicate different from e.g.
> >>
> >> (define_predicate "compare_operator"
> >>   (match_code "compare"))
> >>
> >> ?
> >>
> >> Can you please show generated code from gcc/insn-preds.c?
> >>
> >> Uros.
> >
> > It is different because it has a code block which is used to generate
> > additional function. Here is what generated for the predicate:
> >
> > static inline int
> > x86_64_immediate_size_operand_1 (rtx op, enum machine_mode mode
> > ATTRIBUTE_UNUSED)
> > {
> >   if (!TARGET_64BIT)
> >     return true;
> >
> >   /* For 64 bit target we may assume size of object fits
> >      immediate only when code model guarantees that.  */
> >   return (ix86_cmodel == CM_SMALL || ix86_cmodel == CM_KERNEL);
> > }
> >
> > int
> > x86_64_immediate_size_operand (rtx op, enum machine_mode mode ATTRIBUTE_UNUSED)
> > {
> >   return ((GET_CODE (op) == SYMBOL_REF) && (
> > (x86_64_immediate_size_operand_1 (op, mode)))) && (
> > (mode == VOIDmode || GET_MODE (op) == mode));
> > }
> 
> Well,
> 
> --cut here--
> (define_predicate "x86_64_immediate_size_operand"
>   (and (match_code "symbol_ref")
>        (ior (not (match_test "TARGET_64BIT"))
>             (and (match_test ("ix86_cmodel == CM_SMALL"))
>              (match_test ("ix86_cmodel == CM_KERNEL"))))))
> --cut here--
> 
> Uros.

Thanks for a workaround.  Below is a modified version passing bootstrap.

Ilya
--
2014-10-01  Ilya Enkovich  <ilya.enkovich@intel.com>

	* config/i386/i386.md (UNSPEC_SIZEOF): New.
	(move_size_reloc_<mode>): New.
	* config/i386/predicates.md (symbol_operand): New.
	(x86_64_immediate_size_operand): New.


diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index 65990b1..1901023 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
@@ -18789,6 +18790,21 @@
   "bndstx\t{%2, %3|%3, %2}"
   [(set_attr "type" "mpxst")])
 
+(define_insn "move_size_reloc_<mode>"
+  [(set (match_operand:SWI48 0 "register_operand" "=r")
+       (unspec:SWI48
+        [(match_operand:SWI48 1 "symbol_operand")]
+        UNSPEC_SIZEOF))]
+  "TARGET_MPX"
+{
+  if (x86_64_immediate_size_operand (operands[1], VOIDmode))
+    return "mov{l}\t{%1@SIZE, %k0|%k0, %1@SIZE}";
+  else
+    return "movabs{q}\t{%1@SIZE, %0|%0, %1@SIZE}";
+}
+  [(set_attr "type" "imov")
+   (set_attr "mode" "<MODE>")])
+
 (include "mmx.md")
 (include "sse.md")
 (include "sync.md")
diff --git a/gcc/config/i386/predicates.md b/gcc/config/i386/predicates.md
index fea7754..1875339 100644
--- a/gcc/config/i386/predicates.md
+++ b/gcc/config/i386/predicates.md
@@ -124,6 +124,10 @@
        (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")
@@ -336,6 +340,14 @@
   return false;
 })
 
+;; Return true if size of VALUE can be stored in a sign
+;; extended immediate field.
+(define_predicate "x86_64_immediate_size_operand"
+  (and (match_code "symbol_ref")
+       (ior (not (match_test "TARGET_64BIT"))
+	    (ior (match_test ("ix86_cmodel == CM_SMALL"))
+		 (match_test ("ix86_cmodel == CM_KERNEL"))))))
+
 ;; Return true if OP is general operand representable on x86_64.
 (define_predicate "x86_64_general_operand"
   (if_then_else (match_test "TARGET_64BIT")


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