1 /* FPU control word definitions. PowerPC version. 2 Copyright (C) 1996-2022 Free Software Foundation, Inc. 3 This file is part of the GNU C Library. 4 5 The GNU C Library is free software; you can redistribute it and/or 6 modify it under the terms of the GNU Lesser General Public 7 License as published by the Free Software Foundation; either 8 version 2.1 of the License, or (at your option) any later version. 9 10 The GNU C Library is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 Lesser General Public License for more details. 14 15 You should have received a copy of the GNU Lesser General Public 16 License along with the GNU C Library; if not, see 17 <https://www.gnu.org/licenses/>. */ 18 19 #ifndef _FPU_CONTROL_H 20 #define _FPU_CONTROL_H 21 22 #if defined __SPE__ || (defined __NO_FPRS__ && !defined _SOFT_FLOAT) 23 # error "SPE/e500 is no longer supported" 24 #endif 25 26 #ifdef _SOFT_FLOAT 27 28 # define _FPU_RESERVED 0xffffffff 29 # define _FPU_DEFAULT 0x00000000 /* Default value. */ 30 typedef unsigned int fpu_control_t; 31 # define _FPU_GETCW(cw) (cw) = 0 32 # define _FPU_SETCW(cw) (void) (cw) 33 extern fpu_control_t __fpu_control; 34 35 #else /* PowerPC 6xx floating-point. */ 36 37 /* rounding control */ 38 # define _FPU_RC_NEAREST 0x00 /* RECOMMENDED */ 39 # define _FPU_RC_DOWN 0x03 40 # define _FPU_RC_UP 0x02 41 # define _FPU_RC_ZERO 0x01 42 43 # define _FPU_MASK_RC (_FPU_RC_NEAREST|_FPU_RC_DOWN|_FPU_RC_UP|_FPU_RC_ZERO) 44 45 # define _FPU_MASK_NI 0x04 /* non-ieee mode */ 46 47 /* masking of interrupts */ 48 # define _FPU_MASK_ZM 0x10 /* zero divide */ 49 # define _FPU_MASK_OM 0x40 /* overflow */ 50 # define _FPU_MASK_UM 0x20 /* underflow */ 51 # define _FPU_MASK_XM 0x08 /* inexact */ 52 # define _FPU_MASK_IM 0x80 /* invalid operation */ 53 54 # define _FPU_RESERVED 0xffffff00 /* These bits are reserved are not changed. */ 55 56 /* The fdlibm code requires no interrupts for exceptions. */ 57 # define _FPU_DEFAULT 0x00000000 /* Default value. */ 58 59 /* IEEE: same as above, but (some) exceptions; 60 we leave the 'inexact' exception off. 61 */ 62 # define _FPU_IEEE 0x000000f0 63 64 /* Type of the control word. */ 65 typedef unsigned int fpu_control_t; 66 67 /* Macros for accessing the hardware control word. */ 68 # define _FPU_GETCW(cw) \ 69 ({union { double __d; unsigned long long __ll; } __u; \ 70 __asm__ __volatile__("mffs %0" : "=f" (__u.__d)); \ 71 (cw) = (fpu_control_t) __u.__ll; \ 72 (fpu_control_t) __u.__ll; \ 73 }) 74 75 # define _FPU_GET_RC_ISA300() \ 76 ({union { double __d; unsigned long long __ll; } __u; \ 77 __asm__ __volatile__( \ 78 ".machine push; .machine \"power9\"; mffsl %0; .machine pop" \ 79 : "=f" (__u.__d)); \ 80 (fpu_control_t) (__u.__ll & _FPU_MASK_RC); \ 81 }) 82 83 # ifdef _ARCH_PWR9 84 # define _FPU_GET_RC() _FPU_GET_RC_ISA300() 85 # elif defined __BUILTIN_CPU_SUPPORTS__ 86 # define _FPU_GET_RC() \ 87 ({fpu_control_t __rc; \ 88 __rc = __glibc_likely (__builtin_cpu_supports ("arch_3_00")) \ 89 ? _FPU_GET_RC_ISA300 () \ 90 : _FPU_GETCW (__rc) & _FPU_MASK_RC; \ 91 __rc; \ 92 }) 93 # else 94 # define _FPU_GET_RC() \ 95 ({fpu_control_t __rc = _FPU_GETCW (__rc) & _FPU_MASK_RC; \ 96 __rc; \ 97 }) 98 # endif 99 100 # define _FPU_SETCW(cw) \ 101 { union { double __d; unsigned long long __ll; } __u; \ 102 register double __fr; \ 103 __u.__ll = 0xfff80000LL << 32; /* This is a QNaN. */ \ 104 __u.__ll |= (cw) & 0xffffffffLL; \ 105 __fr = __u.__d; \ 106 __asm__ __volatile__("mtfsf 255,%0" : : "f" (__fr)); \ 107 } 108 109 /* Default control word set at startup. */ 110 extern fpu_control_t __fpu_control; 111 112 #endif /* PowerPC 6xx floating-point. */ 113 114 #endif /* _FPU_CONTROL_H */ 115