commit 302949e2940a9da3f6364a1574619e621b7e1e71
Author: Marcus Shawcroft <marcus.shawcroft@arm.com>
Date:   Fri Mar 7 14:05:20 2014 +0000

    [PATCH] [AArch64] Optional trapping exceptions support.
    
    Trapping exceptions in AArch64 are optional.  The relevant exception
    control bits in FPCR are are defined as RES0 hence the absence of
    support can be detected by reading back the FPCR and comparing with
    the desired value.

--- glibc-2.17-c758a686/ports/sysdeps/aarch64/fpu/feenablxcpt.c
+++ glibc-2.17-c758a686/ports/sysdeps/aarch64/fpu/feenablxcpt.c
@@ -35,5 +35,18 @@ feenableexcept (int excepts)
 
   _FPU_SETCW (fpcr);
 
+  /* Trapping exceptions are optional in AArch64 the relevant enable
+     bits in FPCR are RES0 hence the absence of support can be
+     detected by reading back the FPCR and comparing with the required
+     value.  */
+  if (excepts)
+    {
+      fpu_control_t updated_fpcr;
+
+      _FPU_GETCW (updated_fpcr);
+      if (((updated_fpcr >> FE_EXCEPT_SHIFT) & excepts) != excepts)
+	return -1;
+    }
+
   return original_excepts;
 }
--- glibc-2.17-c758a686/ports/sysdeps/aarch64/fpu/fesetenv.c
+++ glibc-2.17-c758a686/ports/sysdeps/aarch64/fpu/fesetenv.c
@@ -24,6 +24,7 @@ fesetenv (const fenv_t *envp)
 {
   fpu_control_t fpcr;
   fpu_fpsr_t fpsr;
+  fpu_control_t updated_fpcr;
 
   _FPU_GETCW (fpcr);
   _FPU_GETFPSR (fpsr);
@@ -51,6 +52,15 @@ fesetenv (const fenv_t *envp)
 
   _FPU_SETCW (fpcr);
 
+  /* Trapping exceptions are optional in AArch64 the relevant enable
+     bits in FPCR are RES0 hence the absence of support can be
+     detected by reading back the FPCR and comparing with the required
+     value.  */
+
+  _FPU_GETCW (updated_fpcr);
+  if ((updated_fpcr & fpcr) != fpcr)
+    return 1;
+
   return 0;
 }
 
commit 423a7160af7fcffc61aac5e2e36d0b6b5b083214
Author: Wilco <wdijkstr@arm.com>
Date:   Thu Apr 17 09:39:27 2014 +0100

    Add fenv test support for targets which don't have FP traps.

(removed unnecessary code to limit it to test-fenv.c --kyle)

--- glibc-2.17-c758a686/math/test-fenv.c
+++ glibc-2.17-c758a686/math/test-fenv.c
@@ -233,14 +234,9 @@ feenv_nomask_test (const char *flag_name, int fe_exc)
 #if defined FE_NOMASK_ENV
   int status;
   pid_t pid;
-  fenv_t saved;
 
-  fegetenv (&saved);
-  errno = 0;
-  fesetenv (FE_NOMASK_ENV);
-  status = errno;
-  fesetenv (&saved);
-  if (status == ENOSYS)
+  if (1
+      && fesetenv (FE_NOMASK_ENV) != 0)
     {
       printf ("Test: not testing FE_NOMASK_ENV, it isn't implemented.\n");
       return;
@@ -349,7 +345,13 @@ feexcp_nomask_test (const char *flag_name, int fe_exc)
   int status;
   pid_t pid;
 
-  printf ("Test: after fedisableexcept (%s) processes will abort\n",
+  if (1 && feenableexcept (fe_exc) == -1)
+    {
+      printf ("Test: not testing feenableexcept, it isn't implemented.\n");
+      return;
+    }
+
+  printf ("Test: after feenableexcept (%s) processes will abort\n",
 	  flag_name);
   printf ("      when feraiseexcept (%s) is called.\n", flag_name);
   pid = fork ();
@@ -470,7 +472,6 @@ feenable_test (const char *flag_name, int fe_exc)
 {
   int excepts;
 
-
   printf ("Tests for feenableexcepts etc. with flag %s\n", flag_name);
 
   /* First disable all exceptions.  */
@@ -488,8 +489,12 @@ feenable_test (const char *flag_name, int fe_exc)
 	      flag_name, excepts);
       ++count_errors;
     }
-
   excepts = feenableexcept (fe_exc);
+  if (1 && excepts == -1)
+    {
+      printf ("Test: not testing feenableexcept, it isn't implemented.\n");
+      return;
+    }
   if (excepts == -1)
     {
       printf ("Test: feenableexcept (%s) failed\n", flag_name);