diff mbox

[RFC,IPA-VRP] Add support for IPA VRP in ipa-cp/ipa-prop

Message ID 578E9B16.2080100@linaro.org
State Superseded
Headers show

Commit Message

Kugan Vivekanandarajah July 19, 2016, 9:26 p.m. UTC
Hi Martin,


On 19/07/16 18:22, kugan wrote:
> Hi Martin,

>

> Thanks for the review.  I have revised the patch based on the review.

> Please see the comments below.

>


Maybe it is better to separate value range and alignment summary 
writing/reading to different functions. Here is another updated version 
which does this.
This should be more readable and easy to maintain. Bootstrapped (LTO and 
normal) and regression tested on x86-64-linux. There are few test-case 
regressions which I am looking int:

Tests that now fail, but worked before:

27_io/basic_istream/get/char/1.cc execution test
g++.dg/ipa/pure-const-3.C  -std=gnu++11  scan-tree-dump optimized "barvar"
g++.dg/ipa/pure-const-3.C  -std=gnu++14  scan-tree-dump optimized "barvar"
g++.dg/ipa/pure-const-3.C  -std=gnu++98  scan-tree-dump optimized "barvar"
gcc.dg/guality/pr54519-1.c   -O2 -flto -fuse-linker-plugin 
-fno-fat-lto-objects  line 20 y == 25
gcc.dg/guality/pr54519-1.c   -O2 -flto -fuse-linker-plugin 
-fno-fat-lto-objects  line 23 y == 117
gcc.dg/torture/ftrapv-1.c   -O2 -flto -fuse-linker-plugin 
-fno-fat-lto-objects  execution test

New tests that FAIL:

gcc.dg/guality/pr54519-1.c   -O2 -flto -fuse-linker-plugin 
-fno-fat-lto-objects  line 20 z == 6
gcc.dg/guality/pr54519-1.c   -O2 -flto -fuse-linker-plugin 
-fno-fat-lto-objects  line 23 z == 8
gcc.dg/tree-ssa/pr22117.c scan-tree-dump-times evrp "Folding predicate 
r_.* != 0B to 0" 1

I will send the patch with testcase fix and Changelog based on the 
preference.


Thanks,
Kugan
diff mbox

Patch

From 7fe2e29a6ade143c6826a5738e1430fcbe09b05e Mon Sep 17 00:00:00 2001
From: Kugan Vivekanandarajah <kugan.vivekanandarajah@linaro.org>
Date: Tue, 21 Jun 2016 12:43:01 +1000
Subject: [PATCH 5/6] Add ipa vrp

---
 gcc/common.opt                  |   4 +
 gcc/ipa-cp.c                    | 237 +++++++++++++++++++++++++++++++++++++++-
 gcc/ipa-prop.c                  | 214 ++++++++++++++++++++++++++++++++----
 gcc/ipa-prop.h                  |  17 +++
 gcc/testsuite/gcc.dg/ipa/vrp1.c |  32 ++++++
 gcc/testsuite/gcc.dg/ipa/vrp2.c |  35 ++++++
 gcc/testsuite/gcc.dg/ipa/vrp3.c |  30 +++++
 7 files changed, 548 insertions(+), 21 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/ipa/vrp1.c
 create mode 100644 gcc/testsuite/gcc.dg/ipa/vrp2.c
 create mode 100644 gcc/testsuite/gcc.dg/ipa/vrp3.c

diff --git a/gcc/common.opt b/gcc/common.opt
index 29d0e4d..7e3ab5f 100644
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -2475,6 +2475,10 @@  ftree-evrp
 Common Report Var(flag_tree_early_vrp) Init(1) Optimization
 Perform Early Value Range Propagation on trees.
 
+fipa-vrp
+Common Report Var(flag_ipa_vrp) Init(1) Optimization
+Perform IPA Value Range Propagation.
+
 fsplit-paths
 Common Report Var(flag_split_paths) Init(0) Optimization
 Split paths leading to loop backedges.
diff --git a/gcc/ipa-cp.c b/gcc/ipa-cp.c
index 4b7f6bb..760e9da 100644
--- a/gcc/ipa-cp.c
+++ b/gcc/ipa-cp.c
@@ -120,6 +120,7 @@  along with GCC; see the file COPYING3.  If not see
 #include "params.h"
 #include "ipa-inline.h"
 #include "ipa-utils.h"
+#include "tree-vrp.h"
 
 template <typename valtype> class ipcp_value;
 
@@ -266,6 +267,25 @@  private:
   bool meet_with_1 (unsigned new_align, unsigned new_misalign);
 };
 
+/* Lattice of value ranges.  */
+
+class ipcp_vr_lattice
+{
+public:
+  value_range m_vr;
+
+  inline bool bottom_p () const;
+  inline bool top_p () const;
+  inline bool set_to_bottom ();
+  bool meet_with (const value_range *p_vr);
+  bool meet_with (const ipcp_vr_lattice &other);
+  void init () { m_vr.type = VR_UNDEFINED; }
+  void print (FILE * f);
+
+private:
+  bool meet_with_1 (const value_range *other_vr);
+};
+
 /* Structure containing lattices for a parameter itself and for pieces of
    aggregates that are passed in the parameter or by a reference in a parameter
    plus some other useful flags.  */
@@ -281,6 +301,8 @@  public:
   ipcp_agg_lattice *aggs;
   /* Lattice describing known alignment.  */
   ipcp_alignment_lattice alignment;
+  /* Lattice describing value range.  */
+  ipcp_vr_lattice m_value_range;
   /* Number of aggregate lattices */
   int aggs_count;
   /* True if aggregate data were passed by reference (as opposed to by
@@ -348,6 +370,16 @@  ipa_get_poly_ctx_lat (struct ipa_node_params *info, int i)
   return &plats->ctxlat;
 }
 
+/* Return the lattice corresponding to the value range of the Ith formal
+   parameter of the function described by INFO.  */
+
+static inline ipcp_vr_lattice *
+ipa_get_vr_lat (struct ipa_node_params *info, int i)
+{
+  struct ipcp_param_lattices *plats = ipa_get_parm_lattices (info, i);
+  return &plats->m_value_range;
+}
+
 /* Return whether LAT is a lattice with a single constant and without an
    undefined value.  */
 
@@ -458,6 +490,14 @@  ipcp_alignment_lattice::print (FILE * f)
     fprintf (f, "         Alignment %u, misalignment %u\n", align, misalign);
 }
 
+/* Print value range lattice to F.  */
+
+void
+ipcp_vr_lattice::print (FILE * f)
+{
+  dump_value_range (f, &m_vr);
+}
+
 /* Print all ipcp_lattices of all functions to F.  */
 
 static void
@@ -484,6 +524,9 @@  print_all_lattices (FILE * f, bool dump_sources, bool dump_benefits)
 	  fprintf (f, "         ctxs: ");
 	  plats->ctxlat.print (f, dump_sources, dump_benefits);
 	  plats->alignment.print (f);
+	  fprintf (f, "         ");
+	  plats->m_value_range.print (f);
+	  fprintf (f, "\n");
 	  if (plats->virt_call)
 	    fprintf (f, "        virt_call flag set\n");
 
@@ -828,6 +871,77 @@  ipcp_alignment_lattice::set_to_bottom ()
   return true;
 }
 
+/* Meet the current value of the lattice with described by OTHER
+   lattice.  */
+
+bool
+ipcp_vr_lattice::meet_with (const ipcp_vr_lattice &other)
+{
+  return meet_with_1 (&other.m_vr);
+}
+
+/* Meet the current value of the lattice with value ranfge described by VR
+   lattice.  */
+
+bool
+ipcp_vr_lattice::meet_with (const value_range *p_vr)
+{
+  return meet_with_1 (p_vr);
+}
+
+/* Meet the current value of the lattice with value ranfge described by
+   OTHER_VR lattice.  */
+
+bool
+ipcp_vr_lattice::meet_with_1 (const value_range *other_vr)
+{
+  tree min = m_vr.min, max = m_vr.max;
+  value_range_type type = m_vr.type;
+
+  if (bottom_p ())
+    return false;
+
+  if (other_vr->type == VR_VARYING)
+    return set_to_bottom ();
+
+  vrp_meet (&m_vr, other_vr);
+  if (type != m_vr.type
+      || min != m_vr.min
+      || max != m_vr.max)
+    return true;
+  else
+    return false;
+}
+
+/* Return true if value range information in the lattice is yet unknown.  */
+
+bool
+ipcp_vr_lattice::top_p () const
+{
+  return m_vr.type == VR_UNDEFINED;
+}
+
+/* Return true if value range information in the lattice is known to be
+   unusable.  */
+
+bool
+ipcp_vr_lattice::bottom_p () const
+{
+  return m_vr.type == VR_VARYING;
+}
+
+/* Set value range information in the lattice to bottom.  Return true if it
+   previously was in a different state.  */
+
+bool
+ipcp_vr_lattice::set_to_bottom ()
+{
+  if (m_vr.type == VR_VARYING)
+    return false;
+  m_vr.type = VR_VARYING;
+  return true;
+}
+
 /* Meet the current value of the lattice with alignment described by NEW_ALIGN
    and NEW_MISALIGN, assuming that we know the current value is neither TOP nor
    BOTTOM.  Return true if the value of lattice has changed.  */
@@ -915,6 +1029,7 @@  set_all_contains_variable (struct ipcp_param_lattices *plats)
   ret |= plats->ctxlat.set_contains_variable ();
   ret |= set_agg_lats_contain_variable (plats);
   ret |= plats->alignment.set_to_bottom ();
+  ret |= plats->m_value_range.set_to_bottom ();
   return ret;
 }
 
@@ -985,6 +1100,12 @@  initialize_node_lattices (struct cgraph_node *node)
 	disable = true;
     }
 
+  for (i = 0; i < ipa_get_param_count (info) ; i++)
+    {
+      struct ipcp_param_lattices *plats = ipa_get_parm_lattices (info, i);
+      plats->m_value_range.init ();
+    }
+
   if (disable || variable)
     {
       for (i = 0; i < ipa_get_param_count (info) ; i++)
@@ -996,6 +1117,7 @@  initialize_node_lattices (struct cgraph_node *node)
 	      plats->ctxlat.set_to_bottom ();
 	      set_agg_lats_to_bottom (plats);
 	      plats->alignment.set_to_bottom ();
+	      plats->m_value_range.set_to_bottom ();
 	    }
 	  else
 	    set_all_contains_variable (plats);
@@ -1614,7 +1736,49 @@  propagate_alignment_accross_jump_function (cgraph_edge *cs,
     }
 }
 
-/* If DEST_PLATS already has aggregate items, check that aggs_by_ref matches
+/* Propagate value range across jump function JFUNC that is associated with
+   edge CS and update DEST_PLATS accordingly.  */
+
+static bool
+propagate_vr_accross_jump_function (cgraph_edge *cs,
+				    ipa_jump_func *jfunc,
+				    struct ipcp_param_lattices *dest_plats)
+{
+  struct ipcp_param_lattices *src_lats;
+  ipcp_vr_lattice *dest_lat = &dest_plats->m_value_range;
+
+  if (dest_lat->bottom_p ())
+    return false;
+
+  if (jfunc->type == IPA_JF_PASS_THROUGH)
+    {
+      struct ipa_node_params *caller_info = IPA_NODE_REF (cs->caller);
+      int src_idx = ipa_get_jf_pass_through_formal_id (jfunc);
+      src_lats = ipa_get_parm_lattices (caller_info, src_idx);
+
+      if (ipa_get_jf_pass_through_operation (jfunc) == NOP_EXPR)
+	return dest_lat->meet_with (src_lats->m_value_range);
+    }
+  else if (jfunc->type == IPA_JF_CONST)
+    {
+      tree val = ipa_get_jf_constant (jfunc);
+      if (TREE_CODE (val) == INTEGER_CST)
+	{
+	  jfunc->vr_known = true;
+	  jfunc->m_vr.type = VR_RANGE;
+	  jfunc->m_vr.min = val;
+	  jfunc->m_vr.max = val;
+	  return dest_lat->meet_with (&jfunc->m_vr);
+	}
+    }
+
+  if (jfunc->vr_known)
+    return dest_lat->meet_with (&jfunc->m_vr);
+  else
+    return dest_lat->set_to_bottom ();
+}
+
+/* If DEST_PLATS alvrhas aggregate items, check that aggs_by_ref matches
    NEW_AGGS_BY_REF and if not, mark all aggs as bottoms and return true (in all
    other cases, return false).  If there are no aggregate items, set
    aggs_by_ref to NEW_AGGS_BY_REF.  */
@@ -1963,6 +2127,7 @@  propagate_constants_accross_call (struct cgraph_edge *cs)
 							 &dest_plats->alignment);
 	  ret |= propagate_aggs_accross_jump_function (cs, jump_func,
 						       dest_plats);
+	  ret |= propagate_vr_accross_jump_function (cs, jump_func, dest_plats);
 	}
     }
   for (; i < parms_count; i++)
@@ -4585,6 +4750,74 @@  ipcp_store_alignment_results (void)
   }
 }
 
+/* Look up all VR information that we have discovered and copy it over
+   to the transformation summary.  */
+
+static void
+ipcp_store_vr_results (void)
+{
+  cgraph_node *node;
+
+  FOR_EACH_FUNCTION_WITH_GIMPLE_BODY (node)
+  {
+    ipa_node_params *info = IPA_NODE_REF (node);
+    bool found_useful_result = false;
+
+    if (!opt_for_fn (node->decl, flag_ipa_vrp))
+      {
+	if (dump_file)
+	  fprintf (dump_file, "Not considering %s for VR discovery "
+		   "and propagate; -fipa-ipa-vrp: disabled.\n",
+		   node->name ());
+	continue;
+      }
+
+   if (info->ipcp_orig_node)
+      info = IPA_NODE_REF (info->ipcp_orig_node);
+
+   unsigned count = ipa_get_param_count (info);
+   for (unsigned i = 0; i < count ; i++)
+     {
+       ipcp_param_lattices *plats = ipa_get_parm_lattices (info, i);
+       if (!plats->m_value_range.bottom_p ()
+	   && !plats->m_value_range.top_p ())
+	 {
+	   found_useful_result = true;
+	   break;
+	 }
+     }
+   if (!found_useful_result)
+     continue;
+
+   ipcp_grow_transformations_if_necessary ();
+   ipcp_transformation_summary *ts = ipcp_get_transformation_summary (node);
+   vec_safe_reserve_exact (ts->m_vr, count);
+
+   for (unsigned i = 0; i < count ; i++)
+     {
+       ipcp_param_lattices *plats = ipa_get_parm_lattices (info, i);
+       ipa_vr vr;
+
+       if (!plats->m_value_range.bottom_p ()
+	   && !plats->m_value_range.top_p ())
+	 {
+	   vr.known = true;
+	   vr.type = plats->m_value_range.m_vr.type;
+	   vr.min = plats->m_value_range.m_vr.min;
+	   vr.max = plats->m_value_range.m_vr.max;
+	 }
+       else
+	 {
+	   vr.known = false;
+	   vr.type = VR_VARYING;
+	   vr.min = NULL_TREE;
+	   vr.max = NULL_TREE;
+	 }
+       ts->m_vr->quick_push (vr);
+     }
+  }
+}
+
 /* The IPCP driver.  */
 
 static unsigned int
@@ -4618,6 +4851,8 @@  ipcp_driver (void)
   ipcp_decision_stage (&topo);
   /* Store results of alignment propagation. */
   ipcp_store_alignment_results ();
+  /* Store results of value range propagation.  */
+  ipcp_store_vr_results ();
 
   /* Free all IPCP structures.  */
   free_toporder_info (&topo);
diff --git a/gcc/ipa-prop.c b/gcc/ipa-prop.c
index 132b622..de47d3b 100644
--- a/gcc/ipa-prop.c
+++ b/gcc/ipa-prop.c
@@ -41,6 +41,7 @@  along with GCC; see the file COPYING3.  If not see
 #include "gimplify-me.h"
 #include "gimple-walk.h"
 #include "symbol-summary.h"
+#include "tree-vrp.h"
 #include "ipa-prop.h"
 #include "tree-cfg.h"
 #include "tree-dfa.h"
@@ -302,6 +303,19 @@  ipa_print_node_jump_functions_for_edge (FILE *f, struct cgraph_edge *cs)
 	}
       else
 	fprintf (f, "         Unknown alignment\n");
+
+      if (jump_func->vr_known)
+	{
+	  fprintf (f, "         VR  ");
+	  fprintf (f, "%s[",
+		   (jump_func->m_vr.type == VR_ANTI_RANGE) ? "~" : "");
+	  print_generic_expr (f, jump_func->m_vr.min, 0);
+	  fprintf (f, ", ");
+	  print_generic_expr (f, jump_func->m_vr.max, 0);
+	  fprintf (f, "]\n");
+	}
+      else
+	fprintf (f, "         Unknown VR\n");
     }
 }
 
@@ -381,6 +395,7 @@  ipa_set_jf_unknown (struct ipa_jump_func *jfunc)
 {
   jfunc->type = IPA_JF_UNKNOWN;
   jfunc->alignment.known = false;
+  jfunc->vr_known = false;
 }
 
 /* Set JFUNC to be a copy of another jmp (to be used by jump function
@@ -1670,9 +1685,25 @@  ipa_compute_jump_functions_for_edge (struct ipa_func_body_info *fbi,
 	    }
 	  else
 	    gcc_assert (!jfunc->alignment.known);
+	  gcc_assert (!jfunc->vr_known);
 	}
       else
-	gcc_assert (!jfunc->alignment.known);
+	{
+	  wide_int min, max;
+	  value_range_type type;
+	  if (TREE_CODE (arg) == SSA_NAME
+	      && (type = get_range_info (arg, &min, &max))
+	      && (type == VR_RANGE || type == VR_ANTI_RANGE))
+	    {
+	      jfunc->vr_known = true;
+	      jfunc->m_vr.type = type;
+	      jfunc->m_vr.min = wide_int_to_tree (TREE_TYPE (arg), min);
+	      jfunc->m_vr.max = wide_int_to_tree (TREE_TYPE (arg), max);
+	    }
+	  else
+	    gcc_assert (!jfunc->vr_known);
+	  gcc_assert (!jfunc->alignment.known);
+	}
 
       if (is_gimple_ip_invariant (arg)
 	  || (TREE_CODE (arg) == VAR_DECL
@@ -3679,16 +3710,28 @@  ipa_node_params_t::duplicate(cgraph_node *src, cgraph_node *dst,
 
   ipcp_transformation_summary *src_trans = ipcp_get_transformation_summary (src);
 
-  if (src_trans && vec_safe_length (src_trans->alignments) > 0)
+  if (src_trans)
     {
       ipcp_grow_transformations_if_necessary ();
       src_trans = ipcp_get_transformation_summary (src);
       const vec<ipa_alignment, va_gc> *src_alignments = src_trans->alignments;
+      const vec<ipa_vr, va_gc> *src_vr = src_trans->m_vr;
       vec<ipa_alignment, va_gc> *&dst_alignments
 	= ipcp_get_transformation_summary (dst)->alignments;
-      vec_safe_reserve_exact (dst_alignments, src_alignments->length ());
-      for (unsigned i = 0; i < src_alignments->length (); ++i)
-	dst_alignments->quick_push ((*src_alignments)[i]);
+      vec<ipa_vr, va_gc> *&dst_vr
+	= ipcp_get_transformation_summary (dst)->m_vr;
+      if (vec_safe_length (src_trans->alignments) > 0)
+	{
+	  vec_safe_reserve_exact (dst_alignments, src_alignments->length ());
+	  for (unsigned i = 0; i < src_alignments->length (); ++i)
+	    dst_alignments->quick_push ((*src_alignments)[i]);
+	}
+      if (vec_safe_length (src_trans->m_vr) > 0)
+	{
+	  vec_safe_reserve_exact (dst_vr, src_vr->length ());
+	  for (unsigned i = 0; i < src_vr->length (); ++i)
+	    dst_vr->quick_push ((*src_vr)[i]);
+	}
     }
 }
 
@@ -4609,6 +4652,15 @@  ipa_write_jump_function (struct output_block *ob,
       streamer_write_uhwi (ob, jump_func->alignment.align);
       streamer_write_uhwi (ob, jump_func->alignment.misalign);
     }
+  bp_pack_value (&bp, jump_func->vr_known, 1);
+  streamer_write_bitpack (&bp);
+  if (jump_func->vr_known)
+    {
+      streamer_write_enum (ob->main_stream, value_rang_type,
+			   VR_LAST, jump_func->m_vr.type);
+      stream_write_tree (ob, jump_func->m_vr.min, true);
+      stream_write_tree (ob, jump_func->m_vr.max, true);
+    }
 }
 
 /* Read in jump function JUMP_FUNC from IB.  */
@@ -4685,6 +4737,19 @@  ipa_read_jump_function (struct lto_input_block *ib,
     }
   else
     jump_func->alignment.known = false;
+  struct bitpack_d vr_bp = streamer_read_bitpack (ib);
+  bool vr_known = bp_unpack_value (&vr_bp, 1);
+  if (vr_known)
+    {
+      jump_func->vr_known = true;
+      jump_func->m_vr.type = streamer_read_enum (ib,
+						 value_range_type,
+						 VR_LAST);
+      jump_func->m_vr.min = stream_read_tree (ib, data_in);
+      jump_func->m_vr.max = stream_read_tree (ib, data_in);
+    }
+  else
+    jump_func->vr_known = false;
 }
 
 /* Stream out parts of cgraph_indirect_call_info corresponding to CS that are
@@ -5027,29 +5092,59 @@  write_ipcp_transformation_info (output_block *ob, cgraph_node *node)
     }
 
   ipcp_transformation_summary *ts = ipcp_get_transformation_summary (node);
-  if (ts && vec_safe_length (ts->alignments) > 0)
+  if (ts)
     {
-      count = ts->alignments->length ();
-
-      streamer_write_uhwi (ob, count);
-      for (unsigned i = 0; i < count; ++i)
+      if (vec_safe_length (ts->alignments) > 0)
 	{
-	  ipa_alignment *parm_al = &(*ts->alignments)[i];
+	  count = ts->alignments->length ();
+	  streamer_write_uhwi (ob, count);
+	  for (unsigned i = 0; i < count; ++i)
+	    {
+	      struct bitpack_d bp;
+	      ipa_alignment *parm_al = &(*ts->alignments)[i];
+	      bp = bitpack_create (ob->main_stream);
+	      bp_pack_value (&bp, parm_al->known, 1);
+	      streamer_write_bitpack (&bp);
+	      if (parm_al->known)
+		{
+		  streamer_write_uhwi (ob, parm_al->align);
+		  streamer_write_hwi_in_range (ob->main_stream, 0,
+					       parm_al->align,
+					       parm_al->misalign);
+		}
+	    }
+	}
+      else
+	streamer_write_uhwi (ob, 0);
 
-	  struct bitpack_d bp;
-	  bp = bitpack_create (ob->main_stream);
-	  bp_pack_value (&bp, parm_al->known, 1);
-	  streamer_write_bitpack (&bp);
-	  if (parm_al->known)
+      if (vec_safe_length (ts->m_vr) > 0)
+	{
+	  count = ts->m_vr->length ();
+	  streamer_write_uhwi (ob, count);
+	  for (unsigned i = 0; i < count; ++i)
 	    {
-	      streamer_write_uhwi (ob, parm_al->align);
-	      streamer_write_hwi_in_range (ob->main_stream, 0, parm_al->align,
-					   parm_al->misalign);
+	      struct bitpack_d bp;
+	      ipa_vr *parm_vr = &(*ts->m_vr)[i];
+	      bp = bitpack_create (ob->main_stream);
+	      bp_pack_value (&bp, parm_vr->known, 1);
+	      streamer_write_bitpack (&bp);
+	      if (parm_vr->known)
+		{
+		  streamer_write_enum (ob->main_stream, value_rang_type,
+				       VR_LAST, parm_vr->type);
+		  stream_write_tree (ob, parm_vr->min, true);
+		  stream_write_tree (ob, parm_vr->max, true);
+		}
 	    }
 	}
+      else
+	streamer_write_uhwi (ob, 0);
     }
   else
-    streamer_write_uhwi (ob, 0);
+    {
+      streamer_write_uhwi (ob, 0);
+      streamer_write_uhwi (ob, 0);
+    }
 }
 
 /* Stream in the aggregate value replacement chain for NODE from IB.  */
@@ -5102,6 +5197,30 @@  read_ipcp_transformation_info (lto_input_block *ib, cgraph_node *node,
 	    }
 	}
     }
+
+  count = streamer_read_uhwi (ib);
+  if (count > 0)
+    {
+      ipcp_grow_transformations_if_necessary ();
+
+      ipcp_transformation_summary *ts = ipcp_get_transformation_summary (node);
+      vec_safe_grow_cleared (ts->m_vr, count);
+      for (i = 0; i < count; i++)
+	{
+	  ipa_vr *parm_vr;
+	  parm_vr = &(*ts->m_vr)[i];
+	  struct bitpack_d bp;
+	  bp = streamer_read_bitpack (ib);
+	  parm_vr->known = bp_unpack_value (&bp, 1);
+	  if (parm_vr->known)
+	    {
+	      parm_vr->type = streamer_read_enum (ib, value_range_type,
+						  VR_LAST);
+	      parm_vr->min = stream_read_tree (ib, data_in);
+	      parm_vr->max = stream_read_tree (ib, data_in);
+	    }
+	}
+    }
 }
 
 /* Write all aggregate replacement for nodes in set.  */
@@ -5404,6 +5523,60 @@  ipcp_update_alignments (struct cgraph_node *node)
     }
 }
 
+
+/* Update value range of formal parameters as described in
+   ipcp_transformation_summary.  */
+
+static void
+ipcp_update_vr (struct cgraph_node *node)
+{
+  tree fndecl = node->decl;
+  tree parm = DECL_ARGUMENTS (fndecl);
+  tree next_parm = parm;
+  ipcp_transformation_summary *ts = ipcp_get_transformation_summary (node);
+  if (!ts || vec_safe_length (ts->m_vr) == 0)
+    return;
+  const vec<ipa_vr, va_gc> &vr = *ts->m_vr;
+  unsigned count = vr.length ();
+
+  for (unsigned i = 0; i < count; ++i, parm = next_parm)
+    {
+      if (node->clone.combined_args_to_skip
+	  && bitmap_bit_p (node->clone.combined_args_to_skip, i))
+	continue;
+      gcc_checking_assert (parm);
+      next_parm = DECL_CHAIN (parm);
+      tree ddef = ssa_default_def (DECL_STRUCT_FUNCTION (node->decl), parm);
+
+      if (!ddef || !is_gimple_reg (parm))
+	continue;
+
+      if (cgraph_local_p (node)
+	  && vr[i].known
+	  && INTEGRAL_TYPE_P (TREE_TYPE (ddef))
+	  && !POINTER_TYPE_P (TREE_TYPE (ddef))
+	  && (vr[i].type == VR_RANGE || vr[i].type == VR_ANTI_RANGE)
+	  && TREE_CODE (vr[i].min) == INTEGER_CST
+	  && TREE_CODE (vr[i].max) == INTEGER_CST)
+	{
+	  if (dump_file)
+	    {
+	      fprintf (dump_file, "Setting value range of param %u ", i);
+	      fprintf (dump_file, "%s[",
+		       (vr[i].type == VR_ANTI_RANGE) ? "~" : "");
+	      print_generic_expr (dump_file, vr[i].min, 0);
+	      fprintf (dump_file, ", ");
+	      print_generic_expr (dump_file, vr[i].max, 0);
+	      fprintf (dump_file, "]\n");
+	    }
+	  set_range_info (ddef, vr[i].type,
+			  wide_int_to_tree (TREE_TYPE (ddef), vr[i].min),
+			  wide_int_to_tree (TREE_TYPE (ddef), vr[i].max));
+
+	}
+    }
+}
+
 /* IPCP transformation phase doing propagation of aggregate values.  */
 
 unsigned int
@@ -5423,6 +5596,7 @@  ipcp_transform_function (struct cgraph_node *node)
 	     node->name (), node->order);
 
   ipcp_update_alignments (node);
+  ipcp_update_vr (node);
   aggval = ipa_get_agg_replacements_for_node (node);
   if (!aggval)
       return 0;
diff --git a/gcc/ipa-prop.h b/gcc/ipa-prop.h
index e32d078..82c1086 100644
--- a/gcc/ipa-prop.h
+++ b/gcc/ipa-prop.h
@@ -154,6 +154,17 @@  struct GTY(()) ipa_alignment
   unsigned misalign;
 };
 
+/* Info about value ranges.  */
+
+struct GTY(()) ipa_vr
+{
+  /* The data fields below are valid only if known is true.  */
+  bool known;
+  enum value_range_type type;
+  tree min;
+  tree max;
+};
+
 /* A jump function for a callsite represents the values passed as actual
    arguments of the callsite. See enum jump_func_type for the various
    types of jump functions supported.  */
@@ -166,6 +177,10 @@  struct GTY (()) ipa_jump_func
   /* Information about alignment of pointers. */
   struct ipa_alignment alignment;
 
+  /* Information about value range.  */
+  bool vr_known;
+  value_range m_vr;
+
   enum jump_func_type type;
   /* Represents a value of a jump function.  pass_through is used only in jump
      function context.  constant represents the actual constant in constant jump
@@ -482,6 +497,8 @@  struct GTY(()) ipcp_transformation_summary
   ipa_agg_replacement_value *agg_values;
   /* Alignment information for pointers.  */
   vec<ipa_alignment, va_gc> *alignments;
+  /* Value range information.  */
+  vec<ipa_vr, va_gc> *m_vr;
 };
 
 void ipa_set_node_agg_value_chain (struct cgraph_node *node,
diff --git a/gcc/testsuite/gcc.dg/ipa/vrp1.c b/gcc/testsuite/gcc.dg/ipa/vrp1.c
new file mode 100644
index 0000000..72a3139
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/ipa/vrp1.c
@@ -0,0 +1,32 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-ipa-cp-details" } */
+
+static __attribute__((noinline, noclone))
+int foo (int i)
+{
+  if (i < 5)
+    __builtin_abort ();
+  return 0;
+}
+
+static __attribute__((noinline, noclone))
+int bar (int j)
+{
+  if (j > 8)
+    return foo (j + 2);
+  else if (j > 2)
+    return foo (j + 3);
+
+  return 0;
+}
+
+int main ()
+{
+  for (unsigned int i =0; i < 1000; ++i)
+    bar (i);
+
+  return 0;
+}
+
+/* { dg-final { scan-ipa-dump "Setting value range of param 0 \\\[6," "cp" } } */
+/* { dg-final { scan-ipa-dump "Setting value range of param 0 \\\[0, 999\\\]" "cp" } } */
diff --git a/gcc/testsuite/gcc.dg/ipa/vrp2.c b/gcc/testsuite/gcc.dg/ipa/vrp2.c
new file mode 100644
index 0000000..c720e5c
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/ipa/vrp2.c
@@ -0,0 +1,35 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-ipa-cp-details" } */
+
+static __attribute__((noinline, noclone))
+int foo (int i)
+{
+  if (i < 4)
+    __builtin_abort ();
+  return 0;
+}
+
+static __attribute__((noinline, noclone))
+int bar (int j)
+{
+  if (j > 8)
+    return foo (j + 2);
+  else if (j > 2)
+    return foo (j + 3);
+
+  return 0;
+}
+
+int main ()
+{
+  foo (100);
+  for (unsigned int i = 0; i < 12; ++i)
+    {
+      bar (i);
+    }
+  foo (4);
+  return 0;
+}
+
+/* { dg-final { scan-ipa-dump "Setting value range of param 0 \\\[4," "cp" } } */
+/* { dg-final { scan-ipa-dump "Setting value range of param 0 \\\[0, 11\\\]" "cp" } } */
diff --git a/gcc/testsuite/gcc.dg/ipa/vrp3.c b/gcc/testsuite/gcc.dg/ipa/vrp3.c
new file mode 100644
index 0000000..fb5d54a
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/ipa/vrp3.c
@@ -0,0 +1,30 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-ipa-cp-details" } */
+
+volatile int cond;
+
+static __attribute__((noinline, noclone))
+int foo (int i)
+{
+  if (i < 5)
+    __builtin_abort ();
+  return 0;
+}
+
+static __attribute__((noinline, noclone))
+int bar (int j)
+{
+  if (cond)
+    foo (j);
+  return 0;
+}
+
+int main ()
+{
+  for (unsigned int i = 0; i < 10; ++i)
+    bar (i);
+
+  return 0;
+}
+
+/* { dg-final { scan-ipa-dump-times "Setting value range of param 0 \\\[0, 9\\\]" 2 "cp" } } */
-- 
1.9.1