[gcc(refs/vendors/ibm/heads/perf)] tree-optimization/93508 - make VN translate through _chk and valueize length

[Jiu Fu Guo]

https://gcc.gnu.org/g:e431546ff9f1367538ed1307a1c98fa32fec7a8a

commit e431546ff9f1367538ed1307a1c98fa32fec7a8a
Author: Richard Biener <rguenther@suse.de>
Date:   Thu Feb 27 13:46:34 2020 +0100

    tree-optimization/93508 - make VN translate through _chk and valueize length
    
    Value-numbering failed to handle __builtin_{memcpy,memset,...}_chk
    variants when removing abstraction and also failed to use the
    value-numbering lattice when requiring the length argument of the
    call to be constant.
    
    2020-02-27  Richard Biener  <rguenther@suse.de>
    
            PR tree-optimization/93508
            * tree-ssa-sccvn.c (vn_reference_lookup_3): Handle _CHK like
            non-_CHK variants.  Valueize their length arguments.
    
            * gcc.dg/tree-ssa/ssa-fre-85.c: New testcase.

Diff:
---
 gcc/ChangeLog                              |  6 ++++++
 gcc/testsuite/ChangeLog                    |  5 +++++
 gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-87.c | 13 +++++++++++++
 gcc/tree-ssa-sccvn.c                       | 19 +++++++++++++++----
 4 files changed, 39 insertions(+), 4 deletions(-)

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 97419847b62..8c9b7906772 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2020-02-27  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/93508
+	* tree-ssa-sccvn.c (vn_reference_lookup_3): Handle _CHK like
+	non-_CHK variants.  Valueize their length arguments.
+
 2020-02-27  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/93953
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index fa18a159687..6b7b0a2f3d4 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2020-02-27  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/93508
+	* gcc.dg/tree-ssa/ssa-fre-85.c: New testcase.
+
 2020-02-27  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/93953
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-87.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-87.c
new file mode 100644
index 00000000000..6dace16ecbd
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-87.c
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-fre1" } */
+
+unsigned int foo(unsigned int x, int *p)
+{
+  unsigned int src = x;
+  unsigned int dst;
+  *p = sizeof (unsigned int);
+  __builtin___memcpy_chk (&dst, &src, *p, 16);
+  return dst;
+}
+
+/* { dg-final { scan-tree-dump "return x" "fre1" } } */
diff --git a/gcc/tree-ssa-sccvn.c b/gcc/tree-ssa-sccvn.c
index 0487f59f13f..e260ca4eed1 100644
--- a/gcc/tree-ssa-sccvn.c
+++ b/gcc/tree-ssa-sccvn.c
@@ -2537,7 +2537,8 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *data_,
      from that definition.
      1) Memset.  */
   if (is_gimple_reg_type (vr->type)
-      && gimple_call_builtin_p (def_stmt, BUILT_IN_MEMSET)
+      && (gimple_call_builtin_p (def_stmt, BUILT_IN_MEMSET)
+	  || gimple_call_builtin_p (def_stmt, BUILT_IN_MEMSET_CHK))
       && (integer_zerop (gimple_call_arg (def_stmt, 1))
 	  || ((TREE_CODE (gimple_call_arg (def_stmt, 1)) == INTEGER_CST
 	       || (INTEGRAL_TYPE_P (vr->type) && known_eq (ref->size, 8)))
@@ -2548,7 +2549,9 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *data_,
 	      && ref->size.is_constant (&sizei)
 	      && (offseti % BITS_PER_UNIT == 0
 		  || TREE_CODE (gimple_call_arg (def_stmt, 1)) == INTEGER_CST)))
-      && poly_int_tree_p (gimple_call_arg (def_stmt, 2))
+      && (poly_int_tree_p (gimple_call_arg (def_stmt, 2))
+	  || (TREE_CODE (gimple_call_arg (def_stmt, 2)) == SSA_NAME
+	      && poly_int_tree_p (SSA_VAL (gimple_call_arg (def_stmt, 2)))))
       && (TREE_CODE (gimple_call_arg (def_stmt, 0)) == ADDR_EXPR
 	  || TREE_CODE (gimple_call_arg (def_stmt, 0)) == SSA_NAME))
     {
@@ -2609,6 +2612,8 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *data_,
 	return (void *)-1;
       tree len = gimple_call_arg (def_stmt, 2);
       HOST_WIDE_INT leni, offset2i;
+      if (TREE_CODE (len) == SSA_NAME)
+	len = SSA_VAL (len);
       /* Sometimes the above trickery is smarter than alias analysis.  Take
          advantage of that.  */
       if (!ranges_maybe_overlap_p (offset, maxsize, offset2,
@@ -3149,13 +3154,19 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *data_,
 	   && is_gimple_reg_type (vr->type)
 	   /* ???  Handle BCOPY as well.  */
 	   && (gimple_call_builtin_p (def_stmt, BUILT_IN_MEMCPY)
+	       || gimple_call_builtin_p (def_stmt, BUILT_IN_MEMCPY_CHK)
 	       || gimple_call_builtin_p (def_stmt, BUILT_IN_MEMPCPY)
-	       || gimple_call_builtin_p (def_stmt, BUILT_IN_MEMMOVE))
+	       || gimple_call_builtin_p (def_stmt, BUILT_IN_MEMPCPY_CHK)
+	       || gimple_call_builtin_p (def_stmt, BUILT_IN_MEMMOVE)
+	       || gimple_call_builtin_p (def_stmt, BUILT_IN_MEMMOVE_CHK))
 	   && (TREE_CODE (gimple_call_arg (def_stmt, 0)) == ADDR_EXPR
 	       || TREE_CODE (gimple_call_arg (def_stmt, 0)) == SSA_NAME)
 	   && (TREE_CODE (gimple_call_arg (def_stmt, 1)) == ADDR_EXPR
 	       || TREE_CODE (gimple_call_arg (def_stmt, 1)) == SSA_NAME)
-	   && poly_int_tree_p (gimple_call_arg (def_stmt, 2), &copy_size)
+	   && (poly_int_tree_p (gimple_call_arg (def_stmt, 2), &copy_size)
+	       || (TREE_CODE (gimple_call_arg (def_stmt, 2)) == SSA_NAME
+		   && poly_int_tree_p (SSA_VAL (gimple_call_arg (def_stmt, 2)),
+				       &copy_size)))
 	   /* Handling this is more complicated, give up for now.  */
 	   && data->partial_defs.is_empty ())
     {