From be25493251c014a696b62834b0e63b155d8fe353 Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Fri, 27 Jun 2014 14:52:13 +0000 Subject: Fix yn overflow handling in non-default rounding modes (bug 16561, bug 16562). This patch fixes bugs 16561 and 16562, bad results of yn in overflow cases in non-default rounding modes, both because an intermediate overflow in the recurrence does not get detected if the result is not an infinity and because an overflowing result may occur in the wrong sign. The fix is to set FE_TONEAREST mode internally for the parts of the function where such overflows can occur (which includes the call to y1 - where yn is used to compute a Bessel function of order -1, negating the result of y1 isn't correct for overflowing results in directed rounding modes) and then compute an overflowing value in the original rounding mode if the to-nearest result was an infinity. Tested x86_64 and x86 and ulps updated accordingly. Also tested for mips64 and powerpc32 to test the ldbl-128 and ldbl-128ibm changes. (The tests for these bugs were added in my previous y1 patch, so the only thing this patch has to do with the testsuite is enable yn testing in all rounding modes.) [BZ #16561] [BZ #16562] * sysdeps/ieee754/dbl-64/e_jn.c: Include . (__ieee754_yn): Set FE_TONEAREST mode internally and then recompute overflowing results in original rounding mode. * sysdeps/ieee754/flt-32/e_jnf.c: Include . (__ieee754_ynf): Set FE_TONEAREST mode internally and then recompute overflowing results in original rounding mode. * sysdeps/ieee754/ldbl-128/e_jnl.c: Include . (__ieee754_ynl): Set FE_TONEAREST mode internally and then recompute overflowing results in original rounding mode. * sysdeps/ieee754/ldbl-128ibm/e_jnl.c: Include . (__ieee754_ynl): Set FE_TONEAREST mode internally and then recompute overflowing results in original rounding mode. * sysdeps/ieee754/ldbl-96/e_jnl.c: Include . (__ieee754_ynl): Set FE_TONEAREST mode internally and then recompute overflowing results in original rounding mode. * sysdeps/i386/fpu/fenv_private.h [!__SSE2_MATH__] (libc_feholdsetround_ctx): New macro. * math/libm-test.inc (yn_test): Use ALL_RM_TEST. * sysdeps/i386/fpu/libm-test-ulps: Update. * sysdeps/x86_64/fpu/libm-test-ulps : Likewise. --- sysdeps/i386/fpu/fenv_private.h | 1 + sysdeps/i386/fpu/libm-test-ulps | 24 ++++++++++++++++++++++++ 2 files changed, 25 insertions(+) (limited to 'sysdeps/i386') diff --git a/sysdeps/i386/fpu/fenv_private.h b/sysdeps/i386/fpu/fenv_private.h index 3998387c57..e20e1f1662 100644 --- a/sysdeps/i386/fpu/fenv_private.h +++ b/sysdeps/i386/fpu/fenv_private.h @@ -482,6 +482,7 @@ libc_feupdateenv_387_ctx (struct rm_ctx *ctx) #else # define libc_feholdexcept_setround_ctx libc_feholdexcept_setround_387_ctx # define libc_feupdateenv_ctx libc_feupdateenv_387_ctx +# define libc_feholdsetround_ctx libc_feholdsetround_387_ctx # define libc_feresetround_ctx libc_feresetround_387_ctx #endif /* __SSE2_MATH__ */ diff --git a/sysdeps/i386/fpu/libm-test-ulps b/sysdeps/i386/fpu/libm-test-ulps index 7cf958608d..be0e7c3668 100644 --- a/sysdeps/i386/fpu/libm-test-ulps +++ b/sysdeps/i386/fpu/libm-test-ulps @@ -1931,4 +1931,28 @@ ifloat: 3 ildouble: 4 ldouble: 4 +Function: "yn_downward": +double: 2 +float: 2 +idouble: 2 +ifloat: 2 +ildouble: 5 +ldouble: 5 + +Function: "yn_towardzero": +double: 2 +float: 3 +idouble: 2 +ifloat: 3 +ildouble: 5 +ldouble: 5 + +Function: "yn_upward": +double: 2 +float: 3 +idouble: 2 +ifloat: 3 +ildouble: 4 +ldouble: 4 + # end of automatic generation -- cgit 1.4.1