From: Jonathan Wakely <jwakely@redhat.com>
Date: Tue, 28 Jun 2022 08:17:06 +0000 (+0100)
Subject: libstdc++: testsuite: Guard use of C99 std::log2
X-Git-Tag: releases/gcc-12.2.0~104
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c19fe8ad4e2816b181e5d5d3757f1ad59c86cdca;p=thirdparty%2Fgcc.git

libstdc++: testsuite: Guard use of C99 std::log2

This prevents the test from failing if the only thing not supported is
the text printed to the log about the size of the floating-point type.

libstdc++-v3/ChangeLog:

	* testsuite/20_util/from_chars/4.cc: Only use log2 if C99 math
	functions are available.

(cherry picked from commit 30aea28bd30027e0a6be8e3077828256779954b3)
---

diff --git a/libstdc++-v3/testsuite/20_util/from_chars/4.cc b/libstdc++-v3/testsuite/20_util/from_chars/4.cc
index dcd9f97c9467..c27df4ffa5e5 100644
--- a/libstdc++-v3/testsuite/20_util/from_chars/4.cc
+++ b/libstdc++-v3/testsuite/20_util/from_chars/4.cc
@@ -300,9 +300,11 @@ test_max_mantissa()
 
   if (Float_limits::is_iec559 && Float_limits::digits < UInt_limits::digits)
   {
+#ifdef _GLIBCXX_USE_C99_MATH_TR1
     std::printf("Testing %d-bit float, using %zu-bit integer\n",
 	Float_limits::digits + (int)std::log2(Float_limits::max_exponent) + 1,
 	sizeof(UIntT) * __CHAR_BIT__);
+#endif
 
     std::from_chars_result res;
     FloatT flt;