From: Richard Biener <rguenther@suse.de>
Date: Fri, 22 Jan 2021 09:34:42 +0000 (+0100)
Subject: tree-optimization/98786 - fix issue with phiopt and abnormals
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=fd61ca67f97acc5462d02676380af92329c37bb2;p=gcc.git

tree-optimization/98786 - fix issue with phiopt and abnormals

This fixes factor_out_conditional_conversion to avoid creating overlapping
lifetimes for abnormals.  It also makes sure we do deal with a conditional
conversion (at least for one PHI arg def) - for the testcase that wasn't the case.

2021-01-22  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/98786
	* tree-ssa-phiopt.c (factor_out_conditional_conversion): Avoid
	adding new uses of abnormals.  Verify we deal with a conditional
	conversion.

	* gcc.dg/torture/pr98786.c: New testcase.
---

diff --git a/gcc/testsuite/gcc.dg/torture/pr98786.c b/gcc/testsuite/gcc.dg/torture/pr98786.c
new file mode 100644
index 00000000000..ea364717af2
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr98786.c
@@ -0,0 +1,23 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-fno-tree-dce" } */
+
+void
+func_30 (void);
+
+int __attribute__ ((pure, returns_twice))
+func_38 (int g_15, int p_39)
+{
+  return !!g_15 ? p_39 : 0;
+}
+
+void
+func_26 (int func_26___trans_tmp_1)
+{
+  long int l_37 = 0;
+  int __trans_tmp_1;
+
+  func_26___trans_tmp_1 = func_38 (func_26___trans_tmp_1, 1);
+  __trans_tmp_1 = func_38 (func_26___trans_tmp_1, l_37);
+  l_37 = 1;
+  func_30 ();
+}
diff --git a/gcc/tree-ssa-phiopt.c b/gcc/tree-ssa-phiopt.c
index bbc78af6996..ddd9d531b13 100644
--- a/gcc/tree-ssa-phiopt.c
+++ b/gcc/tree-ssa-phiopt.c
@@ -474,6 +474,9 @@ factor_out_conditional_conversion (edge e0, edge e1, gphi *phi,
       if (!is_gimple_reg_type (TREE_TYPE (new_arg0)))
 	return NULL;
     }
+  if (TREE_CODE (new_arg0) == SSA_NAME
+      && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (new_arg0))
+    return NULL;
 
   if (TREE_CODE (arg1) == SSA_NAME)
     {
@@ -484,13 +487,25 @@ factor_out_conditional_conversion (edge e0, edge e1, gphi *phi,
 	  || gimple_assign_rhs_code (arg1_def_stmt) != convert_code)
 	return NULL;
 
+      /* Either arg1_def_stmt or arg0_def_stmt should be conditional.  */
+      if (dominated_by_p (CDI_DOMINATORS, gimple_bb (phi), gimple_bb (arg0_def_stmt))
+	  && dominated_by_p (CDI_DOMINATORS,
+			     gimple_bb (phi), gimple_bb (arg1_def_stmt)))
+	return NULL;
+
       /* Use the RHS as new_arg1.  */
       new_arg1 = gimple_assign_rhs1 (arg1_def_stmt);
       if (convert_code == VIEW_CONVERT_EXPR)
 	new_arg1 = TREE_OPERAND (new_arg1, 0);
+      if (TREE_CODE (new_arg1) == SSA_NAME
+	  && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (new_arg1))
+	return NULL;
     }
   else
     {
+      /* arg0_def_stmt should be conditional.  */
+      if (dominated_by_p (CDI_DOMINATORS, gimple_bb (phi), gimple_bb (arg0_def_stmt)))
+	return NULL;
       /* If arg1 is an INTEGER_CST, fold it to new type.  */
       if (INTEGRAL_TYPE_P (TREE_TYPE (new_arg0))
 	  && int_fits_type_p (arg1, TREE_TYPE (new_arg0)))