[PATCH] testsuite: Fix up gcc.dg/pr126464.c test [PR126464]

On Tue, Aug 04, 2026 at 02:13:19PM +0200, Torbjorn SVENSSON wrote:
> This causes regression on most (all?) arm-none-eabi targets.
> /build/gcc_src/gcc/testsuite/gcc.dg/pr126464.c:56:3: warning: floating constant exceeds range of 'long double' [-Woverflow]

This patch guards it with preprocessor tests whether such floating point
constants are representable.

Tested on x86_64-linux, ok for trunk?

2026-08-04  Jakub Jelinek  <[email protected]>

	PR tree-optimization/126464
	* gcc.dg/pr126464.c: Guard uses of 1e300 with
	__DBL_MAX_10_EXP__ >= 301 and uses of 1e4000L with
	__LDBL_MAX_10_EXP__ >= 4001.

--- gcc/testsuite/gcc.dg/pr126464.c.jj	2026-07-30 09:56:33.400729346 +0200
+++ gcc/testsuite/gcc.dg/pr126464.c	2026-08-04 17:31:18.458149999 +0200
@@ -47,15 +47,19 @@ qux (long double x)
 int
 main ()
 {
+#if __DBL_MAX_10_EXP__ >= 301
   if (!__builtin_isinf ((double) 1e300)
       && __builtin_isinf ((float) 1e300)
       && (foo (-1e300) != -5e299
 	  || baz (1e300) != 5e299))
     __builtin_abort ();
+#endif
 
+#if __LDBL_MAX_10_EXP__ >= 4001
   if (!__builtin_isinf ((long double) 1e4000L)
       && __builtin_isinf ((double) 1e4000L)
       && (bar (1e4000L) != 5e3999L
 	  || qux (-1e4000L) != -5e3999L))
     __builtin_abort ();
+#endif
 }


	Jakub