[PATCH, i386, Pointer Bounds Checker 32/x] Pointer Bounds Checker hooks for i386 target

[Ilya Enkovich <enkovich dot gnu at gmail dot com>]

Hi,

This patch adds i386 target hooks for Pointer Bounds Checker.

Bootstrapped and tested on linux-x86_64.

Thanks,
Ilya
--
gcc/

2014-06-11  Ilya Enkovich  <ilya.enkovich@intel.com>

	* config/i386/i386.c: Include tree-iterator.h.
	(ix86_function_value_bounds): New.
	(ix86_builtin_mpx_function): New.
	(ix86_load_bounds): New.
	(ix86_store_bounds): New.
	(ix86_load_returned_bounds): New.
	(ix86_store_returned_bounds): New.
	(ix86_fn_abi_va_list_bounds_size): New.
	(ix86_mpx_bound_mode): New.
	(ix86_make_bounds_constant): New.
	(ix86_initialize_bounds):
	(TARGET_LOAD_BOUNDS_FOR_ARG): New.
	(TARGET_STORE_BOUNDS_FOR_ARG): New.
	(TARGET_LOAD_RETURNED_BOUNDS): New.
	(TARGET_STORE_RETURNED_BOUNDS): New.
	(TARGET_CHKP_BOUND_MODE): New.
	(TARGET_BUILTIN_CHKP_FUNCTION): New.
	(TARGET_FN_ABI_VA_LIST_BOUNDS_SIZE): New.
	(TARGET_CHKP_FUNCTION_VALUE_BOUNDS): New.
	(TARGET_CHKP_MAKE_BOUNDS_CONSTANT): New.
	(TARGET_CHKP_INITIALIZE_BOUNDS): New.


diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index ac79231..dac83d0 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -81,6 +81,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "context.h"
 #include "pass_manager.h"
 #include "target-globals.h"
+#include "tree-iterator.h"
 #include "tree-chkp.h"
 #include "rtl-chkp.h"
 
@@ -7971,6 +7972,39 @@ ix86_function_value (const_tree valtype, const_tree fntype_or_decl,
   return ix86_function_value_1 (valtype, fntype_or_decl, orig_mode, mode);
 }
 
+static rtx
+ix86_function_value_bounds (const_tree valtype,
+			    const_tree fntype_or_decl ATTRIBUTE_UNUSED,
+			    bool outgoing ATTRIBUTE_UNUSED)
+{
+  rtx res = NULL_RTX;
+
+  if (BOUNDED_TYPE_P (valtype))
+    res = gen_rtx_REG (BNDmode, FIRST_BND_REG);
+  else if (chkp_type_has_pointer (valtype))
+    {
+      bitmap slots = chkp_find_bound_slots (valtype);
+      rtx bounds[2];
+      bitmap_iterator bi;
+      unsigned i, bnd_no = 0;
+
+      EXECUTE_IF_SET_IN_BITMAP (slots, 0, i, bi)
+	{
+	  rtx reg = gen_rtx_REG (BNDmode, FIRST_BND_REG + bnd_no);
+	  rtx offs = GEN_INT (i * POINTER_SIZE / BITS_PER_UNIT);
+	  gcc_assert (bnd_no < 2);
+	  bounds[bnd_no++] = gen_rtx_EXPR_LIST (VOIDmode, reg, offs);
+	}
+
+      res = gen_rtx_PARALLEL (VOIDmode, gen_rtvec_v (bnd_no, bounds));
+      BITMAP_FREE (slots);
+    }
+  else
+    res = NULL_RTX;
+
+  return res;
+}
+
 /* Pointer function arguments and return values are promoted to
    word_mode.  */
 
@@ -36620,6 +36654,173 @@ static tree ix86_get_builtin (enum ix86_builtins code)
     return NULL_TREE;
 }
 
+/* Return function decl for target specific builtin
+   for given MPX builtin passed i FCODE.  */
+static tree
+ix86_builtin_mpx_function (unsigned fcode)
+{
+  switch (fcode)
+    {
+    case BUILT_IN_CHKP_BNDMK:
+      return ix86_builtins[IX86_BUILTIN_BNDMK];
+
+    case BUILT_IN_CHKP_BNDSTX:
+      return ix86_builtins[IX86_BUILTIN_BNDSTX];
+
+    case BUILT_IN_CHKP_BNDLDX:
+      return ix86_builtins[IX86_BUILTIN_BNDLDX];
+
+    case BUILT_IN_CHKP_BNDCL:
+      return ix86_builtins[IX86_BUILTIN_BNDCL];
+
+    case BUILT_IN_CHKP_BNDCU:
+      return ix86_builtins[IX86_BUILTIN_BNDCU];
+
+    case BUILT_IN_CHKP_BNDRET:
+      return ix86_builtins[IX86_BUILTIN_BNDRET];
+
+    case BUILT_IN_CHKP_INTERSECT:
+      return ix86_builtins[IX86_BUILTIN_BNDINT];
+
+    case BUILT_IN_CHKP_NARROW:
+      return ix86_builtins[IX86_BUILTIN_BNDNARROW];
+
+    case BUILT_IN_CHKP_SIZEOF:
+      return ix86_builtins[IX86_BUILTIN_SIZEOF];
+
+    case BUILT_IN_CHKP_EXTRACT_LOWER:
+      return ix86_builtins[IX86_BUILTIN_BNDLOWER];
+
+    case BUILT_IN_CHKP_EXTRACT_UPPER:
+      return ix86_builtins[IX86_BUILTIN_BNDUPPER];
+
+    default:
+      return NULL_TREE;
+    }
+
+  gcc_unreachable ();
+}
+
+/* Load bounds PTR pointer value loaded from SLOT.
+   if SLOT is a register then load bounds associated
+   with special address identified by BND.
+
+   Return loaded bounds.  */
+static rtx
+ix86_load_bounds (rtx slot, rtx ptr, rtx bnd)
+{
+  rtx addr = NULL;
+  rtx reg;
+
+  if (!ptr)
+    {
+      gcc_assert (MEM_P (slot));
+      ptr = copy_to_mode_reg (Pmode, slot);
+    }
+
+  if (!slot || REG_P (slot))
+    {
+      if (slot)
+	ptr = slot;
+
+      gcc_assert (CONST_INT_P (bnd));
+
+      /* Here we have the case when more than four pointers are
+	 passed in registers.  In this case we are out of bound
+	 registers and have to use bndldx to load bound.  RA,
+	 RA - 8, etc. are used for address translation in bndldx.  */
+      addr = plus_constant (Pmode, arg_pointer_rtx, -(INTVAL (bnd) + 1) * 8);
+    }
+  else if (MEM_P (slot))
+    {
+      addr = XEXP (slot, 0);
+      addr = force_reg (Pmode, addr);
+    }
+  else
+    gcc_unreachable ();
+
+  ptr = force_reg (Pmode, ptr);
+  /* If ptr was a register originally then it may have
+     mode other than Pmode.  We need to extend in such
+     case because bndldx may work only with Pmode regs.  */
+  if (GET_MODE (ptr) != Pmode)
+    {
+      rtx ext = gen_rtx_ZERO_EXTEND (Pmode, ptr);
+      ptr = gen_reg_rtx (Pmode);
+      emit_move_insn (ptr, ext);
+    }
+
+  reg = gen_reg_rtx (BNDmode);
+  emit_insn (TARGET_64BIT
+	     ? gen_bnd64_ldx (reg, addr, ptr)
+	     : gen_bnd32_ldx (reg, addr, ptr));
+
+  return reg;
+}
+
+/* Store bounds BOUNDS for PTR pointer value stored in
+   specified ADDR.  If ADDR is a register then TO identifies
+   which special address to use for bounds store.  */
+static void
+ix86_store_bounds (rtx ptr, rtx addr, rtx bounds, rtx to)
+{
+  if (!ptr)
+    {
+      gcc_assert (MEM_P (addr));
+      ptr = copy_to_mode_reg (Pmode, addr);
+    }
+
+  if (!addr || REG_P (addr))
+    {
+      gcc_assert (CONST_INT_P (to));
+      addr = plus_constant (Pmode, stack_pointer_rtx, -(INTVAL (to) + 1) * 8);
+    }
+  else if (MEM_P (addr))
+    addr = XEXP (addr, 0);
+  else
+    gcc_unreachable ();
+
+  /* Should we also ignore integer modes of incorrect size?.  */
+  ptr = force_reg (Pmode, ptr);
+  addr = force_reg (Pmode, addr);
+
+  /* Avoid registers which connot be used as index.  */
+  if (!index_register_operand (ptr, Pmode))
+    {
+      rtx temp = gen_reg_rtx (Pmode);
+      emit_move_insn (temp, ptr);
+      ptr = temp;
+    }
+
+  gcc_assert (POINTER_BOUNDS_MODE_P (GET_MODE (bounds)));
+  bounds = force_reg (GET_MODE (bounds), bounds);
+
+  emit_insn (TARGET_64BIT
+	     ? gen_bnd64_stx (addr, ptr, bounds)
+	     : gen_bnd32_stx (addr, ptr, bounds));
+}
+
+/* Load and return bounds returned by function in SLOT.  */
+static rtx
+ix86_load_returned_bounds (rtx slot)
+{
+  rtx res;
+
+  gcc_assert (REG_P (slot));
+  res = gen_reg_rtx (BNDmode);
+  emit_move_insn (res, slot);
+
+  return res;
+}
+
+/* Store BOUNDS returned by function into SLOT.  */
+static void
+ix86_store_returned_bounds (rtx slot, rtx bounds)
+{
+  gcc_assert (REG_P (slot));
+  emit_move_insn (slot, bounds);
+}
+
 /* Returns a function decl for a vectorized version of the builtin function
    with builtin function code FN and the result vector type TYPE, or NULL_TREE
    if it is not available.  */
@@ -45796,6 +45997,22 @@ ix86_fn_abi_va_list (tree fndecl)
     return sysv_va_list_type_node;
 }
 
+/* This function returns size of bounds for the calling abi
+   specific va_list node.  */
+
+static tree
+ix86_fn_abi_va_list_bounds_size (tree fndecl)
+{
+  if (!TARGET_64BIT)
+    return integer_zero_node;
+  gcc_assert (fndecl != NULL_TREE);
+
+  if (ix86_function_abi ((const_tree) fndecl) == MS_ABI)
+    return integer_zero_node;
+  else
+    return TYPE_SIZE (sysv_va_list_type_node);
+}
+
 /* Returns the canonical va_list type specified by TYPE. If there
    is no valid TYPE provided, it return NULL_TREE.  */
 
@@ -47246,6 +47463,61 @@ ix86_atomic_assign_expand_fenv (tree *hold, tree *clear, tree *update)
 		    atomic_feraiseexcept_call);
 }
 
+static enum machine_mode
+ix86_mpx_bound_mode ()
+{
+  /* Do not support pointer checker if MPX
+     is not enabled.  */
+  if (!TARGET_MPX)
+    {
+      if (flag_check_pointer_bounds)
+	warning (0, "Pointer Checker requires MPX support on this target."
+		 " Use -mmpx options to enable MPX.");
+      return VOIDmode;
+    }
+
+  return BNDmode;
+}
+
+static tree
+ix86_make_bounds_constant (HOST_WIDE_INT lb, HOST_WIDE_INT ub)
+{
+  tree low = lb ? build_minus_one_cst (pointer_sized_int_node)
+    : build_zero_cst (pointer_sized_int_node);
+  tree high = ub ? build_zero_cst (pointer_sized_int_node)
+    : build_minus_one_cst (pointer_sized_int_node);
+
+  /* This function is supposed to be used to create zero and
+     none bounds only.  */
+  gcc_assert (lb == 0 || lb == -1);
+  gcc_assert (ub == 0 || ub == -1);
+
+  return build_complex (NULL, low, high);
+}
+
+static int
+ix86_initialize_bounds (tree var, tree lb, tree ub, tree *stmts)
+{
+  tree size_ptr = build_pointer_type (size_type_node);
+  tree lhs, modify, var_p;
+
+  ub = build1 (BIT_NOT_EXPR, size_type_node, ub);
+  var_p = build1 (CONVERT_EXPR, size_ptr,
+		  build_fold_addr_expr (var));
+
+  lhs = build1 (INDIRECT_REF, size_type_node, var_p);
+  modify = build2 (MODIFY_EXPR, TREE_TYPE (lhs), lhs, lb);
+  append_to_statement_list (modify, stmts);
+
+  lhs = build1 (INDIRECT_REF, size_type_node,
+		build2 (POINTER_PLUS_EXPR, size_ptr, var_p,
+			TYPE_SIZE_UNIT (size_type_node)));
+  modify = build2 (MODIFY_EXPR, TREE_TYPE (lhs), lhs, ub);
+  append_to_statement_list (modify, stmts);
+
+  return 2;
+}
+
 /* Initialize the GCC target structure.  */
 #undef TARGET_RETURN_IN_MEMORY
 #define TARGET_RETURN_IN_MEMORY ix86_return_in_memory
@@ -47642,6 +47914,36 @@ ix86_atomic_assign_expand_fenv (tree *hold, tree *clear, tree *update)
 #define TARGET_FLOAT_EXCEPTIONS_ROUNDING_SUPPORTED_P \
   ix86_float_exceptions_rounding_supported_p
 
+#undef TARGET_LOAD_BOUNDS_FOR_ARG
+#define TARGET_LOAD_BOUNDS_FOR_ARG ix86_load_bounds
+
+#undef TARGET_STORE_BOUNDS_FOR_ARG
+#define TARGET_STORE_BOUNDS_FOR_ARG ix86_store_bounds
+
+#undef TARGET_LOAD_RETURNED_BOUNDS
+#define TARGET_LOAD_RETURNED_BOUNDS ix86_load_returned_bounds
+
+#undef TARGET_STORE_RETURNED_BOUNDS
+#define TARGET_STORE_RETURNED_BOUNDS ix86_store_returned_bounds
+
+#undef TARGET_CHKP_BOUND_MODE
+#define TARGET_CHKP_BOUND_MODE ix86_mpx_bound_mode
+
+#undef TARGET_BUILTIN_CHKP_FUNCTION
+#define TARGET_BUILTIN_CHKP_FUNCTION ix86_builtin_mpx_function
+
+#undef TARGET_FN_ABI_VA_LIST_BOUNDS_SIZE
+#define TARGET_FN_ABI_VA_LIST_BOUNDS_SIZE ix86_fn_abi_va_list_bounds_size
+
+#undef TARGET_CHKP_FUNCTION_VALUE_BOUNDS
+#define TARGET_CHKP_FUNCTION_VALUE_BOUNDS ix86_function_value_bounds
+
+#undef TARGET_CHKP_MAKE_BOUNDS_CONSTANT
+#define TARGET_CHKP_MAKE_BOUNDS_CONSTANT ix86_make_bounds_constant
+
+#undef TARGET_CHKP_INITIALIZE_BOUNDS
+#define TARGET_CHKP_INITIALIZE_BOUNDS ix86_initialize_bounds
+
 struct gcc_target targetm = TARGET_INITIALIZER;
 
 #include "gt-i386.h"