[PR 82808] Use result types for arithmetic jump functions

[Martin Jambor]

On Tue, Nov 28 2017, Martin Jambor wrote:
>
...
>
> Done, this is what I have just committed.  I will prepare a conservative
> fix for gcc 7 with only the expr_type_first_operand_type_p part.
>

The following is what I have committed to the gcc-7-branch after a round
of bootstrap and testing on an x86_64-linux.

Thanks,

Martin


2017-11-29  Martin Jambor  <mjambor@suse.cz>

	PR ipa/82808
	* tree.c (expr_type_first_operand_type_p): New function.
	* tree.h (expr_type_first_operand_type_p): Declare it.
	* ipa-cp.c (ipa_get_jf_pass_through_result): Use it.

testsuite/
	* gcc.dg/ipa/pr82808.c: New test.
---
 gcc/ipa-cp.c                       | 26 +++++++++++-----------
 gcc/testsuite/gcc.dg/ipa/pr82808.c | 27 +++++++++++++++++++++++
 gcc/tree.c                         | 44 ++++++++++++++++++++++++++++++++++++++
 gcc/tree.h                         |  1 +
 4 files changed, 85 insertions(+), 13 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/ipa/pr82808.c

diff --git a/gcc/ipa-cp.c b/gcc/ipa-cp.c
index fa3d5fd7548..716c8cc3a1f 100644
--- a/gcc/ipa-cp.c
+++ b/gcc/ipa-cp.c
@@ -1224,20 +1224,20 @@ ipa_get_jf_pass_through_result (struct ipa_jump_func *jfunc, tree input)
   if (!is_gimple_ip_invariant (input))
     return NULL_TREE;
 
-  if (TREE_CODE_CLASS (ipa_get_jf_pass_through_operation (jfunc))
-      == tcc_unary)
-    res = fold_unary (ipa_get_jf_pass_through_operation (jfunc),
-		      TREE_TYPE (input), input);
+  tree_code opcode = ipa_get_jf_pass_through_operation (jfunc);
+  if (TREE_CODE_CLASS (opcode) == tcc_comparison)
+    restype = boolean_type_node;
+  else if (expr_type_first_operand_type_p (opcode))
+    restype = TREE_TYPE (input);
   else
-    {
-      if (TREE_CODE_CLASS (ipa_get_jf_pass_through_operation (jfunc))
-	  == tcc_comparison)
-	restype = boolean_type_node;
-      else
-	restype = TREE_TYPE (input);
-      res = fold_binary (ipa_get_jf_pass_through_operation (jfunc), restype,
-			 input, ipa_get_jf_pass_through_operand (jfunc));
-    }
+    return NULL_TREE;
+
+  if (TREE_CODE_CLASS (opcode) == tcc_unary)
+    res = fold_unary (opcode, restype, input);
+  else
+    res = fold_binary (opcode, restype, input,
+		       ipa_get_jf_pass_through_operand (jfunc));
+
   if (res && !is_gimple_ip_invariant (res))
     return NULL_TREE;
 
diff --git a/gcc/testsuite/gcc.dg/ipa/pr82808.c b/gcc/testsuite/gcc.dg/ipa/pr82808.c
new file mode 100644
index 00000000000..9c95d0b6ed7
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/ipa/pr82808.c
@@ -0,0 +1,27 @@
+/* { dg-options "-O2" } */
+/* { dg-do run } */
+
+static void __attribute__((noinline))
+foo (double *a, double x)
+{
+  *a = x;
+}
+
+static double  __attribute__((noinline))
+f_c1 (int m, double *a)
+{
+  foo (a, m);
+  return *a;
+}
+
+int
+main (){
+  double data;
+  double ret = 0 ;
+
+  if ((ret = f_c1 (2, &data)) != 2)
+    {
+      __builtin_abort ();
+    }
+  return 0;
+}
diff --git a/gcc/tree.c b/gcc/tree.c
index 69425ab59ee..698213c3501 100644
--- a/gcc/tree.c
+++ b/gcc/tree.c
@@ -14515,6 +14515,50 @@ get_nonnull_args (const_tree fntype)
   return argmap;
 }
 
+/* Return true if an expression with CODE has to have the same result type as
+   its first operand.  */
+
+bool
+expr_type_first_operand_type_p (tree_code code)
+{
+  switch (code)
+    {
+    case NEGATE_EXPR:
+    case ABS_EXPR:
+    case BIT_NOT_EXPR:
+    case PAREN_EXPR:
+    case CONJ_EXPR:
+
+    case PLUS_EXPR:
+    case MINUS_EXPR:
+    case MULT_EXPR:
+    case TRUNC_DIV_EXPR:
+    case CEIL_DIV_EXPR:
+    case FLOOR_DIV_EXPR:
+    case ROUND_DIV_EXPR:
+    case TRUNC_MOD_EXPR:
+    case CEIL_MOD_EXPR:
+    case FLOOR_MOD_EXPR:
+    case ROUND_MOD_EXPR:
+    case RDIV_EXPR:
+    case EXACT_DIV_EXPR:
+    case MIN_EXPR:
+    case MAX_EXPR:
+    case BIT_IOR_EXPR:
+    case BIT_XOR_EXPR:
+    case BIT_AND_EXPR:
+
+    case LSHIFT_EXPR:
+    case RSHIFT_EXPR:
+    case LROTATE_EXPR:
+    case RROTATE_EXPR:
+      return true;
+
+    default:
+      return false;
+    }
+}
+
 #if CHECKING_P
 
 namespace selftest {
diff --git a/gcc/tree.h b/gcc/tree.h
index 375edcd4ba6..f20b77f17e4 100644
--- a/gcc/tree.h
+++ b/gcc/tree.h
@@ -5471,6 +5471,7 @@ extern void gt_pch_nx (tree &, gt_pointer_operator, void *);
 
 extern bool nonnull_arg_p (const_tree);
 extern bool is_redundant_typedef (const_tree);
+extern bool expr_type_first_operand_type_p (tree_code);
 
 extern location_t
 set_source_range (tree expr, location_t start, location_t finish);
-- 
2.15.0