Use C2x return value from getpayload of non-NaN (bug 26073).

In TS 18661-1, getpayload had an unspecified return value for a
non-NaN argument, while C2x requires the return value -1 in that case.

This patch implements the return value of -1.  I don't think this is
worth having a new symbol version that's an alias of the old one,
although occasionally we do that in such cases where the new function
semantics are a refinement of the old ones (to avoid programs relying
on the new semantics running on older glibc versions but not behaving
as intended).

Tested for x86_64 and x86; also ran math/ tests for aarch64 and
powerpc.

1 files changed, 3 insertions, 0 deletions

diff --git a/sysdeps/ieee754/flt-32/s_getpayloadf.c b/sysdeps/ieee754/flt-32/s_getpayloadf.c
index e1d22473ff..1baad4847e 100644
--- a/sysdeps/ieee754/flt-32/s_getpayloadf.c
+++ b/sysdeps/ieee754/flt-32/s_getpayloadf.c
@@ -27,6 +27,9 @@ __getpayloadf (const float *x)
 {
   uint32_t ix;
   GET_FLOAT_WORD (ix, *x);
+  if ((ix & 0x7f800000) != 0x7f800000
+      || (ix & 0x7fffff) == 0)
+    return -1;
   ix &= 0x3fffff;
   if (FIX_INT_FP_CONVERT_ZERO && ix == 0)
     return 0.0f;