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From: Joseph Myers <>
Subject: [gcc r13-2689] float.h: Do not define INFINITY for C2x when infinities not supported
Date: Thu, 15 Sep 2022 20:11:28 +0000 (GMT)	[thread overview]
Message-ID: <> (raw)

commit r13-2689-g6248f4ff67502c88d92f55fa5ea5996937220e5c
Author: Joseph Myers <>
Date:   Thu Sep 15 20:10:42 2022 +0000

    float.h: Do not define INFINITY for C2x when infinities not supported
    C2x has changed the rules for defining INFINITY in <float.h> so it is
    no longer defined when float does not support infinities, instead of
    being defined to an expression that overflows at translation time.
    Thus, make the definition conditional on __FLT_HAS_INFINITY__ (this is
    already inside a C2x-conditional part of <float.h>, because previous C
    standard versions only had this macro in <math.h>).
    Bootstrapped with no regressions for x86_64-pc-linux-gnu.  Also did a
    spot test of the case of no infinities supported by building cc1 for
    vax-netbsdelf and testing compiling the new c2x-float-11.c test with
            * ginclude/float.h (INFINITY): Define only if
            * gcc.dg/c2x-float-2.c: Require inff effective-target.
            * gcc.dg/c2x-float-11.c: New test.

 gcc/ginclude/float.h                | 4 +++-
 gcc/testsuite/gcc.dg/c2x-float-11.c | 9 +++++++++
 gcc/testsuite/gcc.dg/c2x-float-2.c  | 4 ++--
 3 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/gcc/ginclude/float.h b/gcc/ginclude/float.h
index 9d368c4afa5..afe4a712878 100644
--- a/gcc/ginclude/float.h
+++ b/gcc/ginclude/float.h
@@ -257,9 +257,11 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 #define DBL_IS_IEC_60559	__DBL_IS_IEC_60559__
 #define LDBL_IS_IEC_60559	__LDBL_IS_IEC_60559__
-/* Infinity in type float, or overflow if infinity not supported.  */
+/* Infinity in type float; not defined if infinity not supported.  */
 #undef INFINITY
 #define INFINITY	(__builtin_inff ())
 /* Quiet NaN, if supported for float.  */
diff --git a/gcc/testsuite/gcc.dg/c2x-float-11.c b/gcc/testsuite/gcc.dg/c2x-float-11.c
new file mode 100644
index 00000000000..0e2f3c0c97a
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/c2x-float-11.c
@@ -0,0 +1,9 @@
+/* Test INFINITY macro.  Test when infinities not supported.  */
+/* { dg-do compile { target { ! inff } } } */
+/* { dg-options "-std=c2x" } */
+#include <float.h>
+#ifdef INFINITY
+#error "INFINITY defined"
diff --git a/gcc/testsuite/gcc.dg/c2x-float-2.c b/gcc/testsuite/gcc.dg/c2x-float-2.c
index 4f669fd39bc..61a77f6f2db 100644
--- a/gcc/testsuite/gcc.dg/c2x-float-2.c
+++ b/gcc/testsuite/gcc.dg/c2x-float-2.c
@@ -1,8 +1,8 @@
-/* Test INFINITY macro.  Generic test even if infinities not
-   supported.  */
+/* Test INFINITY macro.  Generic test.  */
 /* { dg-do run } */
 /* { dg-options "-std=c2x -w" } */
 /* { dg-add-options ieee } */
+/* { dg-require-effective-target inff } */
 #include <float.h>

                 reply	other threads:[~2022-09-15 20:11 UTC|newest]

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