From: Daniel Arndt <daniel.arndt@iwr.uni-heidelberg.de>
Date: Sat, 26 Jan 2019 15:13:16 +0000 (+0100)
Subject: Don't use __builtin_expect in Utilities::pow
X-Git-Tag: v9.1.0-rc1~400^2
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d10fed17a8ab6fc7b7634a8727e2944dbc74f2aa;p=dealii.git

Don't use __builtin_expect in Utilities::pow
---

diff --git a/include/deal.II/base/utilities.h b/include/deal.II/base/utilities.h
index f2a1cb6b6e..f49c302132 100644
--- a/include/deal.II/base/utilities.h
+++ b/include/deal.II/base/utilities.h
@@ -404,9 +404,10 @@ namespace Utilities
   constexpr unsigned int
   pow(const unsigned int base, const int iexp)
   {
-#ifdef DEAL_II_WITH_CXX14
-#  ifdef DEAL_II_HAVE_CXX14_CONSTEXPR_CAN_CALL_NONCONSTEXPR
-#    if defined(DEAL_II_HAVE_BUILTIN_EXPECT) && defined(__INTEL_COMPILER)
+#if defined(DEBUG) && defined(DEAL_II_WITH_CXX14) && \
+  defined(DEAL_II_HAVE_CXX14_CONSTEXPR_CAN_CALL_NONCONSTEXPR)
+    // Up to __builtin_expect this is the same code as in the 'Assert' macro.
+    // The call to __builtin_expect turns out to be problematic.
     if (!(iexp >= 0))
       ::dealii::deal_II_exceptions::internals::issue_error_noreturn(
         ::dealii::deal_II_exceptions::internals::abort_or_throw_on_exception,
@@ -416,10 +417,6 @@ namespace Utilities
         "iexp>=0",
         "ExcMessage(\"The exponent must not be negative!\")",
         ExcMessage("The exponent must not be negative!"));
-#    else
-    Assert(iexp >= 0, ExcMessage("The exponent must not be negative!"));
-#    endif
-#  endif
 #endif
     // The "exponentiation by squaring" algorithm used below has to be
     // compressed to one statement due to C++11's restrictions on constexpr