From: Jason Merrill <jason@redhat.com>
Date: Wed, 26 Nov 2014 18:20:18 +0000 (-0500)
Subject: constexpr.c (cxx_eval_constant_expression): Avoid multiple evaluation.
X-Git-Tag: releases/gcc-5.1.0~2798
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=cabaf50ac511cdedd2710faf87c126996483c3e5;p=thirdparty%2Fgcc.git

constexpr.c (cxx_eval_constant_expression): Avoid multiple evaluation.

	* constexpr.c (cxx_eval_constant_expression) [SAVE_EXPR]: Avoid
	multiple evaluation.

From-SVN: r218093
---

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index e961169fea33..32092c418a15 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,8 @@
 2014-11-26  Jason Merrill  <jason@redhat.com>
 
+	* constexpr.c (cxx_eval_constant_expression) [SAVE_EXPR]: Avoid
+	multiple evaluation.
+
 	* constexpr.c (cxx_eval_call_expression): Don't talk about
 	flowing off the end if we're already non-constant.
 
diff --git a/gcc/cp/constexpr.c b/gcc/cp/constexpr.c
index 111ea5b1a010..ef9ef70d6e0b 100644
--- a/gcc/cp/constexpr.c
+++ b/gcc/cp/constexpr.c
@@ -2974,11 +2974,22 @@ cxx_eval_constant_expression (const constexpr_ctx *ctx, tree t,
       *jump_target = t;
       break;
 
+    case SAVE_EXPR:
+      /* Avoid evaluating a SAVE_EXPR more than once.  */
+      if (tree *p = ctx->values->get (t))
+	r = *p;
+      else
+	{
+	  r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), addr,
+					    non_constant_p, overflow_p);
+	  ctx->values->put (t, r);
+	}
+      break;
+
     case NON_LVALUE_EXPR:
     case TRY_CATCH_EXPR:
     case CLEANUP_POINT_EXPR:
     case MUST_NOT_THROW_EXPR:
-    case SAVE_EXPR:
     case EXPR_STMT:
     case EH_SPEC_BLOCK:
       r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0),