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Diffstat (limited to 'REORG.TODO/sysdeps/alpha/fpu/fpu_control.h')
| -rw-r--r-- | REORG.TODO/sysdeps/alpha/fpu/fpu_control.h | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/alpha/fpu/fpu_control.h b/REORG.TODO/sysdeps/alpha/fpu/fpu_control.h new file mode 100644 index 0000000000..fbb55e5461 --- /dev/null +++ b/REORG.TODO/sysdeps/alpha/fpu/fpu_control.h @@ -0,0 +1,105 @@ +/* FPU control word bits. Alpha-mapped-to-Intel version. + Copyright (C) 1996-2017 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Olaf Flebbe. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library. If not, see + <http://www.gnu.org/licenses/>. */ + +#ifndef _ALPHA_FPU_CONTROL_H +#define _ALPHA_FPU_CONTROL_H + +/* + * Since many programs seem to hardcode the values passed to __setfpucw() + * (rather than using the manifest constants) we emulate the x87 interface + * here (at least where this makes sense). + * + * 15-13 12 11-10 9-8 7-6 5 4 3 2 1 0 + * | reserved | IC | RC | PC | reserved | PM | UM | OM | ZM | DM | IM + * + * IM: Invalid operation mask + * DM: Denormalized operand mask + * ZM: Zero-divide mask + * OM: Overflow mask + * UM: Underflow mask + * PM: Precision (inexact result) mask + * + * Mask bit is 1 means no interrupt. + * + * PC: Precision control + * 11 - round to extended precision + * 10 - round to double precision + * 00 - round to single precision + * + * RC: Rounding control + * 00 - rounding to nearest + * 01 - rounding down (toward - infinity) + * 10 - rounding up (toward + infinity) + * 11 - rounding toward zero + * + * IC: Infinity control + * That is for 8087 and 80287 only. + * + * The hardware default is 0x037f. I choose 0x1372. + */ + +#include <features.h> + +/* masking of interrupts */ +#define _FPU_MASK_IM 0x01 +#define _FPU_MASK_DM 0x02 +#define _FPU_MASK_ZM 0x04 +#define _FPU_MASK_OM 0x08 +#define _FPU_MASK_UM 0x10 +#define _FPU_MASK_PM 0x20 + +/* precision control -- without effect on Alpha */ +#define _FPU_EXTENDED 0x300 /* RECOMMENDED */ +#define _FPU_DOUBLE 0x200 +#define _FPU_SINGLE 0x0 /* DO NOT USE */ + +/* + * rounding control---notice that on the Alpha this affects only + * instructions with the dynamic rounding mode qualifier (/d). + */ +#define _FPU_RC_NEAREST 0x000 /* RECOMMENDED */ +#define _FPU_RC_DOWN 0x400 +#define _FPU_RC_UP 0x800 +#define _FPU_RC_ZERO 0xC00 + +#define _FPU_RESERVED 0xF0C0 /* Reserved bits in cw */ + + +/* Now two recommended cw */ + +/* Linux default: + - extended precision + - rounding to positive infinity. There is no /p instruction + qualifier. By setting the dynamic rounding mode to +infinity, + one can use /d to get round to +infinity with no extra overhead + (so long as the default isn't changed, of course...) + - no exceptions enabled. */ + +#define _FPU_DEFAULT 0x137f + +/* IEEE: same as above. */ +#define _FPU_IEEE 0x137f + +/* Type of the control word. */ +typedef unsigned int fpu_control_t; + +/* Default control word set at startup. */ +extern fpu_control_t __fpu_control; + +#endif /* _ALPHA_FPU_CONTROL */ |