Test cpow in all rounding modes.

This patch enables testing of cpow in all rounding modes using
ALL_RM_TEST.  There were two reasons this was previously deferred:

* MPC has complicated rounding-mode-dependent rules for the signs of
  exact zero real or imaginary parts in the result of mpc_pow.  Annex
  G does not impose any such requirements and I don't think glibc
  should try to implement any particular logic here.  This patch adds
  support for gen-auto-libm-tests passing the IGNORE_ZERO_INF_SIGN
  flag to libm-test.inc.

* Error accumulations in some tests in non-default rounding modes
  exceed the maximum error permitted in libm-test.inc.  This patch
  marks the problem tests with xfail-rounding.  (It might be possible
  to reduce the accumulations a bit by using round-to-nearest when
  cpow calls clog, but I don't think there's much point; the
  implementation approach for cpow is fundamentally deficient, as
  discussed in the existing bug for cpow inaccuracy which can
  reasonably be considered to cover these less-inaccurate cases as
  well.  It's possible that the test "cpow 2 0 10 0" will also need
  xfail-rounding on some platforms.)

Tested x86_64 and x86 and ulps updated accordingly.

	* math/gen-auto-libm-tests.c: Document use of
	ignore-zero-inf-sign.
	(input_flag_type): Add value flag_ignore_zero_inf_sign.
	(input_flags): Add ignore-zero-inf-sign.
	(output_for_one_input_case): Handle flag_ignore_zero_inf_sign.
	* math/gen-libm-test.pl (generate_testfile): Handle
	ignore-zero-inf-sign.
	* math/auto-libm-test-in: Mark some cpow tests with
	ignore-zero-inf-sign and some with xfail-rounding.
	* math/auto-libm-test-out: Regenerated.
	* math/libm-test.inc (cpow_test): Use ALL_RM_TEST.
	* sysdeps/i386/fpu/libm-test-ulps: Update.
	* sysdeps/x86_64/fpu/libm-test-ulps: Likewise.

2 files changed, 96 insertions, 0 deletions

diff --git a/sysdeps/i386/fpu/libm-test-ulps b/sysdeps/i386/fpu/libm-test-ulps
index eb934e36c4..8d9c83d0ca 100644
--- a/sysdeps/i386/fpu/libm-test-ulps
+++ b/sysdeps/i386/fpu/libm-test-ulps
@@ -916,6 +916,54 @@ ifloat: 1
 ildouble: 4
 ldouble: 4
 
+Function: Real part of "cpow_downward":
+double: 5
+float: 8
+idouble: 5
+ifloat: 8
+ildouble: 7
+ldouble: 7
+
+Function: Imaginary part of "cpow_downward":
+double: 1
+float: 1
+idouble: 1
+ifloat: 1
+ildouble: 2
+ldouble: 2
+
+Function: Real part of "cpow_towardzero":
+double: 5
+float: 8
+idouble: 5
+ifloat: 8
+ildouble: 7
+ldouble: 7
+
+Function: Imaginary part of "cpow_towardzero":
+double: 1
+float: 1
+idouble: 1
+ifloat: 1
+ildouble: 1
+ldouble: 1
+
+Function: Real part of "cpow_upward":
+double: 4
+float: 1
+idouble: 4
+ifloat: 1
+ildouble: 2
+ldouble: 2
+
+Function: Imaginary part of "cpow_upward":
+double: 1
+float: 1
+idouble: 1
+ifloat: 1
+ildouble: 2
+ldouble: 2
+
 Function: Real part of "csin":
 double: 1
 float: 1
diff --git a/sysdeps/x86_64/fpu/libm-test-ulps b/sysdeps/x86_64/fpu/libm-test-ulps
index 8edd40b640..5469887099 100644
--- a/sysdeps/x86_64/fpu/libm-test-ulps
+++ b/sysdeps/x86_64/fpu/libm-test-ulps
@@ -959,6 +959,54 @@ ifloat: 2
 ildouble: 4
 ldouble: 4
 
+Function: Real part of "cpow_downward":
+double: 4
+float: 8
+idouble: 4
+ifloat: 8
+ildouble: 7
+ldouble: 7
+
+Function: Imaginary part of "cpow_downward":
+double: 2
+float: 2
+idouble: 2
+ifloat: 2
+ildouble: 2
+ldouble: 2
+
+Function: Real part of "cpow_towardzero":
+double: 4
+float: 8
+idouble: 4
+ifloat: 8
+ildouble: 7
+ldouble: 7
+
+Function: Imaginary part of "cpow_towardzero":
+double: 2
+float: 2
+idouble: 2
+ifloat: 2
+ildouble: 1
+ldouble: 1
+
+Function: Real part of "cpow_upward":
+double: 4
+float: 1
+idouble: 4
+ifloat: 1
+ildouble: 2
+ldouble: 2
+
+Function: Imaginary part of "cpow_upward":
+double: 1
+float: 2
+idouble: 1
+ifloat: 2
+ildouble: 2
+ldouble: 2
+
 Function: Real part of "csin":
 double: 1
 float: 1