diff options
Diffstat (limited to 'sysdeps/alpha/fpu/s_ceil.c')
| -rw-r--r-- | sysdeps/alpha/fpu/s_ceil.c | 36 |
1 files changed, 16 insertions, 20 deletions
diff --git a/sysdeps/alpha/fpu/s_ceil.c b/sysdeps/alpha/fpu/s_ceil.c index 23491db5ac..f30db008ce 100644 --- a/sysdeps/alpha/fpu/s_ceil.c +++ b/sysdeps/alpha/fpu/s_ceil.c @@ -1,4 +1,4 @@ -/* Copyright (C) 1998 Free Software Foundation, Inc. +/* Copyright (C) 1998, 2000 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Richard Henderson. @@ -19,34 +19,30 @@ #include <math.h> +/* Use the -inf rounding mode conversion instructions to implement + ceil, via something akin to -floor(-x). This is much faster than + playing with the fpcr to achieve +inf rounding mode. */ + double __ceil (double x) { - if (x != 0 && fabs (x) < 9007199254740992.0) /* 1 << DBL_MANT_DIG */ + if (isless (fabs (x), 9007199254740992.0)) /* 1 << DBL_MANT_DIG */ { - double tmp1; - unsigned long fpcr0, fpcr1; - unsigned long pinf = 3UL << 58; - - /* Set round to +inf. */ - __asm __volatile("excb; mf_fpcr %0" : "=f"(fpcr0)); - __asm __volatile("mt_fpcr %0; excb" : : "f"(fpcr0 | pinf)); + double tmp1, new_x; - /* Calculate! */ + new_x = -x; + __asm ( #ifdef _IEEE_FP_INEXACT - __asm("cvttq/svid %2,%1\n\tcvtqt/suid %1,%0" - : "=f"(x), "=&f"(tmp1) - : "f"(x)); + "cvttq/svim %2,%1\n\t" #else - __asm("cvttq/svd %2,%1\n\tcvtqt/d %1,%0" - : "=f"(x), "=&f"(tmp1) - : "f"(x)); + "cvttq/svm %2,%1\n\t" #endif + "cvtqt/m %1,%0\n\t" + : "=f"(new_x), "=&f"(tmp1) + : "f"(new_x)); - /* Reset rounding mode, while retaining new exception bits. */ - __asm __volatile("excb; mf_fpcr %0" : "=f"(fpcr1)); - fpcr0 = (fpcr0 & pinf) | (fpcr1 & ~pinf); - __asm __volatile("mt_fpcr %0; excb" : : "f"(fpcr0)); + /* Fix up the negation we did above, as well as handling -0 properly. */ + x = copysign(new_x, x); } return x; } |