From 6c4ee1aba17f1e71b9ec856479260de9d362fdb6 Mon Sep 17 00:00:00 2001
From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date: Wed, 9 Mar 2022 15:36:53 -0300
Subject: stdlib: Fix macro expansion producing 'defined' has undefined
 behavior

The FPIOCONST_HAVE_EXTENDED_RANGE is defined as:

  #define FPIOCONST_HAVE_EXTENDED_RANGE \
    ((!defined __NO_LONG_DOUBLE_MATH && __LDBL_MAX_EXP__ > 1024) \
    || __HAVE_DISTINCT_FLOAT128)

Which is undefined behavior accordingly to C Standard (Preprocessing
directives, p4).

Checked on x86_64-linux-gnu.
---
 stdlib/fpioconst.h | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

(limited to 'stdlib')

diff --git a/stdlib/fpioconst.h b/stdlib/fpioconst.h
index 1e01999941..3e185f5751 100644
--- a/stdlib/fpioconst.h
+++ b/stdlib/fpioconst.h
@@ -52,9 +52,12 @@
    - LDBL_MIN_EXP + 2)).  When _Float128 is enabled in libm and it is
    ABI-distinct from long double (e.g. on powerpc64le), we also need powers
    of 10 up to floor (log_2 (FLT128_MANT_DIG - FLT128_MIN_EXP + 2)).  */
-#define FPIOCONST_HAVE_EXTENDED_RANGE \
-  ((!defined __NO_LONG_DOUBLE_MATH && __LDBL_MAX_EXP__ > 1024) \
-   || __HAVE_DISTINCT_FLOAT128)
+#if (!defined __NO_LONG_DOUBLE_MATH && __LDBL_MAX_EXP__ > 1024) \
+    || __HAVE_DISTINCT_FLOAT128
+# define FPIOCONST_HAVE_EXTENDED_RANGE 1
+#else
+# define FPIOCONST_HAVE_EXTENDED_RANGE 0
+#endif
 
 #if FPIOCONST_HAVE_EXTENDED_RANGE
 # define FPIOCONST_POW10_ARRAY_SIZE	15
-- 
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