344 lines
12 KiB
C
344 lines
12 KiB
C
|
/* Machine-dependent software floating-point definitions. PPC version.
|
||
|
|
Copyright (C) 1997 Free Software Foundation, Inc.
|
||
|
|
This file is part of the GNU C Library.
|
||
|
|
|
||
|
|
The GNU C Library is free software; you can redistribute it and/or
|
||
|
|
modify it under the terms of the GNU Library General Public License as
|
||
|
|
published by the Free Software Foundation; either version 2 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
|
||
|
|
Library General Public License for more details.
|
||
|
|
|
||
|
|
You should have received a copy of the GNU Library General Public
|
||
|
|
License along with the GNU C Library; see the file COPYING.LIB. If
|
||
|
|
not, write to the Free Software Foundation, Inc.,
|
||
|
|
59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
|
||
|
|
|
||
|
|
Actually, this is a PPC (32bit) version, written based on the
|
||
|
|
i386, sparc, and sparc64 versions, by me,
|
||
|
|
Peter Maydell (pmaydell@chiark.greenend.org.uk).
|
||
|
|
Comments are by and large also mine, although they may be inaccurate.
|
||
|
|
|
||
|
|
In picking out asm fragments I've gone with the lowest common
|
||
|
|
denominator, which also happens to be the hardware I have :->
|
||
|
|
That is, a SPARC without hardware multiply and divide.
|
||
|
|
*/
|
||
|
|
|
||
|
|
/* basic word size definitions */
|
||
|
|
#define _FP_W_TYPE_SIZE 32
|
||
|
|
#define _FP_W_TYPE unsigned int
|
||
|
|
#define _FP_WS_TYPE signed int
|
||
|
|
#define _FP_I_TYPE int
|
||
|
|
|
||
|
|
#define __ll_B ((UWtype) 1 << (W_TYPE_SIZE / 2))
|
||
|
|
#define __ll_lowpart(t) ((UWtype) (t) & (__ll_B - 1))
|
||
|
|
#define __ll_highpart(t) ((UWtype) (t) >> (W_TYPE_SIZE / 2))
|
||
|
|
|
||
|
|
/* You can optionally code some things like addition in asm. For
|
||
|
|
* example, i386 defines __FP_FRAC_ADD_2 as asm. If you don't
|
||
|
|
* then you get a fragment of C code [if you change an #ifdef 0
|
||
|
|
* in op-2.h] or a call to add_ssaaaa (see below).
|
||
|
|
* Good places to look for asm fragments to use are gcc and glibc.
|
||
|
|
* gcc's longlong.h is useful.
|
||
|
|
*/
|
||
|
|
|
||
|
|
/* We need to know how to multiply and divide. If the host word size
|
||
|
|
* is >= 2*fracbits you can use FP_MUL_MEAT_n_imm(t,R,X,Y) which
|
||
|
|
* codes the multiply with whatever gcc does to 'a * b'.
|
||
|
|
* _FP_MUL_MEAT_n_wide(t,R,X,Y,f) is used when you have an asm
|
||
|
|
* function that can multiply two 1W values and get a 2W result.
|
||
|
|
* Otherwise you're stuck with _FP_MUL_MEAT_n_hard(t,R,X,Y) which
|
||
|
|
* does bitshifting to avoid overflow.
|
||
|
|
* For division there is FP_DIV_MEAT_n_imm(t,R,X,Y,f) for word size
|
||
|
|
* >= 2*fracbits, where f is either _FP_DIV_HELP_imm or
|
||
|
|
* _FP_DIV_HELP_ldiv (see op-1.h).
|
||
|
|
* _FP_DIV_MEAT_udiv() is if you have asm to do 2W/1W => (1W, 1W).
|
||
|
|
* [GCC and glibc have longlong.h which has the asm macro udiv_qrnnd
|
||
|
|
* to do this.]
|
||
|
|
* In general, 'n' is the number of words required to hold the type,
|
||
|
|
* and 't' is either S, D or Q for single/double/quad.
|
||
|
|
* -- PMM
|
||
|
|
*/
|
||
|
|
/* Example: SPARC64:
|
||
|
|
* #define _FP_MUL_MEAT_S(R,X,Y) _FP_MUL_MEAT_1_imm(S,R,X,Y)
|
||
|
|
* #define _FP_MUL_MEAT_D(R,X,Y) _FP_MUL_MEAT_1_wide(D,R,X,Y,umul_ppmm)
|
||
|
|
* #define _FP_MUL_MEAT_Q(R,X,Y) _FP_MUL_MEAT_2_wide(Q,R,X,Y,umul_ppmm)
|
||
|
|
*
|
||
|
|
* #define _FP_DIV_MEAT_S(R,X,Y) _FP_DIV_MEAT_1_imm(S,R,X,Y,_FP_DIV_HELP_imm)
|
||
|
|
* #define _FP_DIV_MEAT_D(R,X,Y) _FP_DIV_MEAT_1_udiv(D,R,X,Y)
|
||
|
|
* #define _FP_DIV_MEAT_Q(R,X,Y) _FP_DIV_MEAT_2_udiv_64(Q,R,X,Y)
|
||
|
|
*
|
||
|
|
* Example: i386:
|
||
|
|
* #define _FP_MUL_MEAT_S(R,X,Y) _FP_MUL_MEAT_1_wide(S,R,X,Y,_i386_mul_32_64)
|
||
|
|
* #define _FP_MUL_MEAT_D(R,X,Y) _FP_MUL_MEAT_2_wide(D,R,X,Y,_i386_mul_32_64)
|
||
|
|
*
|
||
|
|
* #define _FP_DIV_MEAT_S(R,X,Y) _FP_DIV_MEAT_1_udiv(S,R,X,Y,_i386_div_64_32)
|
||
|
|
* #define _FP_DIV_MEAT_D(R,X,Y) _FP_DIV_MEAT_2_udiv_64(D,R,X,Y)
|
||
|
|
*/
|
||
|
|
|
||
|
|
#define _FP_MUL_MEAT_S(R,X,Y) _FP_MUL_MEAT_1_wide(_FP_WFRACBITS_S,R,X,Y,umul_ppmm)
|
||
|
|
#define _FP_MUL_MEAT_D(R,X,Y) _FP_MUL_MEAT_2_wide(_FP_WFRACBITS_D,R,X,Y,umul_ppmm)
|
||
|
|
|
||
|
|
#define _FP_DIV_MEAT_S(R,X,Y) _FP_DIV_MEAT_1_udiv_norm(S,R,X,Y)
|
||
|
|
#define _FP_DIV_MEAT_D(R,X,Y) _FP_DIV_MEAT_2_udiv(D,R,X,Y)
|
||
|
|
|
||
|
|
/* These macros define what NaN looks like. They're supposed to expand to
|
||
|
|
* a comma-separated set of 32bit unsigned ints that encode NaN.
|
||
|
|
*/
|
||
|
|
#define _FP_NANFRAC_S ((_FP_QNANBIT_S << 1) - 1)
|
||
|
|
#define _FP_NANFRAC_D ((_FP_QNANBIT_D << 1) - 1), -1
|
||
|
|
#define _FP_NANFRAC_Q ((_FP_QNANBIT_Q << 1) - 1), -1, -1, -1
|
||
|
|
#define _FP_NANSIGN_S 0
|
||
|
|
#define _FP_NANSIGN_D 0
|
||
|
|
#define _FP_NANSIGN_Q 0
|
||
|
|
|
||
|
|
#define _FP_KEEPNANFRACP 1
|
||
|
|
|
||
|
|
#ifdef FP_EX_BOOKE_E500_SPE
|
||
|
|
#define FP_EX_INEXACT (1 << 21)
|
||
|
|
#define FP_EX_INVALID (1 << 20)
|
||
|
|
#define FP_EX_DIVZERO (1 << 19)
|
||
|
|
#define FP_EX_UNDERFLOW (1 << 18)
|
||
|
|
#define FP_EX_OVERFLOW (1 << 17)
|
||
|
|
#define FP_INHIBIT_RESULTS 0
|
||
|
|
|
||
|
|
#define __FPU_FPSCR (current->thread.spefscr)
|
||
|
|
#define __FPU_ENABLED_EXC \
|
||
|
|
({ \
|
||
|
|
(__FPU_FPSCR >> 2) & 0x1f; \
|
||
|
|
})
|
||
|
|
#else
|
||
|
|
/* Exception flags. We use the bit positions of the appropriate bits
|
||
|
|
in the FPSCR, which also correspond to the FE_* bits. This makes
|
||
|
|
everything easier ;-). */
|
||
|
|
#define FP_EX_INVALID (1 << (31 - 2))
|
||
|
|
#define FP_EX_INVALID_SNAN EFLAG_VXSNAN
|
||
|
|
#define FP_EX_INVALID_ISI EFLAG_VXISI
|
||
|
|
#define FP_EX_INVALID_IDI EFLAG_VXIDI
|
||
|
|
#define FP_EX_INVALID_ZDZ EFLAG_VXZDZ
|
||
|
|
#define FP_EX_INVALID_IMZ EFLAG_VXIMZ
|
||
|
|
#define FP_EX_OVERFLOW (1 << (31 - 3))
|
||
|
|
#define FP_EX_UNDERFLOW (1 << (31 - 4))
|
||
|
|
#define FP_EX_DIVZERO (1 << (31 - 5))
|
||
|
|
#define FP_EX_INEXACT (1 << (31 - 6))
|
||
|
|
|
||
|
|
#define __FPU_FPSCR (current->thread.fp_state.fpscr)
|
||
|
|
|
||
|
|
/* We only actually write to the destination register
|
||
|
|
* if exceptions signalled (if any) will not trap.
|
||
|
|
*/
|
||
|
|
#define __FPU_ENABLED_EXC \
|
||
|
|
({ \
|
||
|
|
(__FPU_FPSCR >> 3) & 0x1f; \
|
||
|
|
})
|
||
|
|
|
||
|
|
#endif
|
||
|
|
|
||
|
|
/*
|
||
|
|
* If one NaN is signaling and the other is not,
|
||
|
|
* we choose that one, otherwise we choose X.
|
||
|
|
*/
|
||
|
|
#define _FP_CHOOSENAN(fs, wc, R, X, Y, OP) \
|
||
|
|
do { \
|
||
|
|
if ((_FP_FRAC_HIGH_RAW_##fs(Y) & _FP_QNANBIT_##fs) \
|
||
|
|
&& !(_FP_FRAC_HIGH_RAW_##fs(X) & _FP_QNANBIT_##fs)) \
|
||
|
|
{ \
|
||
|
|
R##_s = X##_s; \
|
||
|
|
_FP_FRAC_COPY_##wc(R,X); \
|
||
|
|
} \
|
||
|
|
else \
|
||
|
|
{ \
|
||
|
|
R##_s = Y##_s; \
|
||
|
|
_FP_FRAC_COPY_##wc(R,Y); \
|
||
|
|
} \
|
||
|
|
R##_c = FP_CLS_NAN; \
|
||
|
|
} while (0)
|
||
|
|
|
||
|
|
|
||
|
|
#include <linux/kernel.h>
|
||
|
|
#include <linux/sched.h>
|
||
|
|
|
||
|
|
#define __FPU_TRAP_P(bits) \
|
||
|
|
((__FPU_ENABLED_EXC & (bits)) != 0)
|
||
|
|
|
||
|
|
#define __FP_PACK_S(val,X) \
|
||
|
|
({ int __exc = _FP_PACK_CANONICAL(S,1,X); \
|
||
|
|
if(!__exc || !__FPU_TRAP_P(__exc)) \
|
||
|
|
_FP_PACK_RAW_1_P(S,val,X); \
|
||
|
|
__exc; \
|
||
|
|
})
|
||
|
|
|
||
|
|
#define __FP_PACK_D(val,X) \
|
||
|
|
do { \
|
||
|
|
_FP_PACK_CANONICAL(D, 2, X); \
|
||
|
|
if (!FP_CUR_EXCEPTIONS || !__FPU_TRAP_P(FP_CUR_EXCEPTIONS)) \
|
||
|
|
_FP_PACK_RAW_2_P(D, val, X); \
|
||
|
|
} while (0)
|
||
|
|
|
||
|
|
#define __FP_PACK_DS(val,X) \
|
||
|
|
do { \
|
||
|
|
FP_DECL_S(__X); \
|
||
|
|
FP_CONV(S, D, 1, 2, __X, X); \
|
||
|
|
_FP_PACK_CANONICAL(S, 1, __X); \
|
||
|
|
if (!FP_CUR_EXCEPTIONS || !__FPU_TRAP_P(FP_CUR_EXCEPTIONS)) { \
|
||
|
|
_FP_UNPACK_CANONICAL(S, 1, __X); \
|
||
|
|
FP_CONV(D, S, 2, 1, X, __X); \
|
||
|
|
_FP_PACK_CANONICAL(D, 2, X); \
|
||
|
|
if (!FP_CUR_EXCEPTIONS || !__FPU_TRAP_P(FP_CUR_EXCEPTIONS)) \
|
||
|
|
_FP_PACK_RAW_2_P(D, val, X); \
|
||
|
|
} \
|
||
|
|
} while (0)
|
||
|
|
|
||
|
|
/* Obtain the current rounding mode. */
|
||
|
|
#define FP_ROUNDMODE \
|
||
|
|
({ \
|
||
|
|
__FPU_FPSCR & 0x3; \
|
||
|
|
})
|
||
|
|
|
||
|
|
/* the asm fragments go here: all these are taken from glibc-2.0.5's
|
||
|
|
* stdlib/longlong.h
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <linux/types.h>
|
||
|
|
#include <asm/byteorder.h>
|
||
|
|
|
||
|
|
/* add_ssaaaa is used in op-2.h and should be equivalent to
|
||
|
|
* #define add_ssaaaa(sh,sl,ah,al,bh,bl) (sh = ah+bh+ (( sl = al+bl) < al))
|
||
|
|
* add_ssaaaa(high_sum, low_sum, high_addend_1, low_addend_1,
|
||
|
|
* high_addend_2, low_addend_2) adds two UWtype integers, composed by
|
||
|
|
* HIGH_ADDEND_1 and LOW_ADDEND_1, and HIGH_ADDEND_2 and LOW_ADDEND_2
|
||
|
|
* respectively. The result is placed in HIGH_SUM and LOW_SUM. Overflow
|
||
|
|
* (i.e. carry out) is not stored anywhere, and is lost.
|
||
|
|
*/
|
||
|
|
#define add_ssaaaa(sh, sl, ah, al, bh, bl) \
|
||
|
|
do { \
|
||
|
|
if (__builtin_constant_p (bh) && (bh) == 0) \
|
||
|
|
__asm__ ("add%I4c %1,%3,%4\n\taddze %0,%2" \
|
||
|
|
: "=r" (sh), "=&r" (sl) : "r" (ah), "%r" (al), "rI" (bl));\
|
||
|
|
else if (__builtin_constant_p (bh) && (bh) == ~(USItype) 0) \
|
||
|
|
__asm__ ("add%I4c %1,%3,%4\n\taddme %0,%2" \
|
||
|
|
: "=r" (sh), "=&r" (sl) : "r" (ah), "%r" (al), "rI" (bl));\
|
||
|
|
else \
|
||
|
|
__asm__ ("add%I5c %1,%4,%5\n\tadde %0,%2,%3" \
|
||
|
|
: "=r" (sh), "=&r" (sl) \
|
||
|
|
: "%r" (ah), "r" (bh), "%r" (al), "rI" (bl)); \
|
||
|
|
} while (0)
|
||
|
|
|
||
|
|
/* sub_ddmmss is used in op-2.h and udivmodti4.c and should be equivalent to
|
||
|
|
* #define sub_ddmmss(sh, sl, ah, al, bh, bl) (sh = ah-bh - ((sl = al-bl) > al))
|
||
|
|
* sub_ddmmss(high_difference, low_difference, high_minuend, low_minuend,
|
||
|
|
* high_subtrahend, low_subtrahend) subtracts two two-word UWtype integers,
|
||
|
|
* composed by HIGH_MINUEND_1 and LOW_MINUEND_1, and HIGH_SUBTRAHEND_2 and
|
||
|
|
* LOW_SUBTRAHEND_2 respectively. The result is placed in HIGH_DIFFERENCE
|
||
|
|
* and LOW_DIFFERENCE. Overflow (i.e. carry out) is not stored anywhere,
|
||
|
|
* and is lost.
|
||
|
|
*/
|
||
|
|
#define sub_ddmmss(sh, sl, ah, al, bh, bl) \
|
||
|
|
do { \
|
||
|
|
if (__builtin_constant_p (ah) && (ah) == 0) \
|
||
|
|
__asm__ ("subf%I3c %1,%4,%3\n\tsubfze %0,%2" \
|
||
|
|
: "=r" (sh), "=&r" (sl) : "r" (bh), "rI" (al), "r" (bl));\
|
||
|
|
else if (__builtin_constant_p (ah) && (ah) == ~(USItype) 0) \
|
||
|
|
__asm__ ("subf%I3c %1,%4,%3\n\tsubfme %0,%2" \
|
||
|
|
: "=r" (sh), "=&r" (sl) : "r" (bh), "rI" (al), "r" (bl));\
|
||
|
|
else if (__builtin_constant_p (bh) && (bh) == 0) \
|
||
|
|
__asm__ ("subf%I3c %1,%4,%3\n\taddme %0,%2" \
|
||
|
|
: "=r" (sh), "=&r" (sl) : "r" (ah), "rI" (al), "r" (bl));\
|
||
|
|
else if (__builtin_constant_p (bh) && (bh) == ~(USItype) 0) \
|
||
|
|
__asm__ ("subf%I3c %1,%4,%3\n\taddze %0,%2" \
|
||
|
|
: "=r" (sh), "=&r" (sl) : "r" (ah), "rI" (al), "r" (bl));\
|
||
|
|
else \
|
||
|
|
__asm__ ("subf%I4c %1,%5,%4\n\tsubfe %0,%3,%2" \
|
||
|
|
: "=r" (sh), "=&r" (sl) \
|
||
|
|
: "r" (ah), "r" (bh), "rI" (al), "r" (bl)); \
|
||
|
|
} while (0)
|
||
|
|
|
||
|
|
/* asm fragments for mul and div */
|
||
|
|
|
||
|
|
/* umul_ppmm(high_prod, low_prod, multipler, multiplicand) multiplies two
|
||
|
|
* UWtype integers MULTIPLER and MULTIPLICAND, and generates a two UWtype
|
||
|
|
* word product in HIGH_PROD and LOW_PROD.
|
||
|
|
*/
|
||
|
|
#define umul_ppmm(ph, pl, m0, m1) \
|
||
|
|
do { \
|
||
|
|
USItype __m0 = (m0), __m1 = (m1); \
|
||
|
|
__asm__ ("mulhwu %0,%1,%2" : "=r" (ph) : "%r" (m0), "r" (m1)); \
|
||
|
|
(pl) = __m0 * __m1; \
|
||
|
|
} while (0)
|
||
|
|
|
||
|
|
/* udiv_qrnnd(quotient, remainder, high_numerator, low_numerator,
|
||
|
|
* denominator) divides a UDWtype, composed by the UWtype integers
|
||
|
|
* HIGH_NUMERATOR and LOW_NUMERATOR, by DENOMINATOR and places the quotient
|
||
|
|
* in QUOTIENT and the remainder in REMAINDER. HIGH_NUMERATOR must be less
|
||
|
|
* than DENOMINATOR for correct operation. If, in addition, the most
|
||
|
|
* significant bit of DENOMINATOR must be 1, then the pre-processor symbol
|
||
|
|
* UDIV_NEEDS_NORMALIZATION is defined to 1.
|
||
|
|
*/
|
||
|
|
#define udiv_qrnnd(q, r, n1, n0, d) \
|
||
|
|
do { \
|
||
|
|
UWtype __d1, __d0, __q1, __q0; \
|
||
|
|
UWtype __r1, __r0, __m; \
|
||
|
|
__d1 = __ll_highpart (d); \
|
||
|
|
__d0 = __ll_lowpart (d); \
|
||
|
|
\
|
||
|
|
__r1 = (n1) % __d1; \
|
||
|
|
__q1 = (n1) / __d1; \
|
||
|
|
__m = (UWtype) __q1 * __d0; \
|
||
|
|
__r1 = __r1 * __ll_B | __ll_highpart (n0); \
|
||
|
|
if (__r1 < __m) \
|
||
|
|
{ \
|
||
|
|
__q1--, __r1 += (d); \
|
||
|
|
if (__r1 >= (d)) /* i.e. we didn't get carry when adding to __r1 */\
|
||
|
|
if (__r1 < __m) \
|
||
|
|
__q1--, __r1 += (d); \
|
||
|
|
} \
|
||
|
|
__r1 -= __m; \
|
||
|
|
\
|
||
|
|
__r0 = __r1 % __d1; \
|
||
|
|
__q0 = __r1 / __d1; \
|
||
|
|
__m = (UWtype) __q0 * __d0; \
|
||
|
|
__r0 = __r0 * __ll_B | __ll_lowpart (n0); \
|
||
|
|
if (__r0 < __m) \
|
||
|
|
{ \
|
||
|
|
__q0--, __r0 += (d); \
|
||
|
|
if (__r0 >= (d)) \
|
||
|
|
if (__r0 < __m) \
|
||
|
|
__q0--, __r0 += (d); \
|
||
|
|
} \
|
||
|
|
__r0 -= __m; \
|
||
|
|
\
|
||
|
|
(q) = (UWtype) __q1 * __ll_B | __q0; \
|
||
|
|
(r) = __r0; \
|
||
|
|
} while (0)
|
||
|
|
|
||
|
|
#define UDIV_NEEDS_NORMALIZATION 1
|
||
|
|
|
||
|
|
#define abort() \
|
||
|
|
return 0
|
||
|
|
|
||
|
|
#ifdef __BIG_ENDIAN
|
||
|
|
#define __BYTE_ORDER __BIG_ENDIAN
|
||
|
|
#else
|
||
|
|
#define __BYTE_ORDER __LITTLE_ENDIAN
|
||
|
|
#endif
|
||
|
|
|
||
|
|
/* Exception flags. */
|
||
|
|
#define EFLAG_INVALID (1 << (31 - 2))
|
||
|
|
#define EFLAG_OVERFLOW (1 << (31 - 3))
|
||
|
|
#define EFLAG_UNDERFLOW (1 << (31 - 4))
|
||
|
|
#define EFLAG_DIVZERO (1 << (31 - 5))
|
||
|
|
#define EFLAG_INEXACT (1 << (31 - 6))
|
||
|
|
|
||
|
|
#define EFLAG_VXSNAN (1 << (31 - 7))
|
||
|
|
#define EFLAG_VXISI (1 << (31 - 8))
|
||
|
|
#define EFLAG_VXIDI (1 << (31 - 9))
|
||
|
|
#define EFLAG_VXZDZ (1 << (31 - 10))
|
||
|
|
#define EFLAG_VXIMZ (1 << (31 - 11))
|
||
|
|
#define EFLAG_VXVC (1 << (31 - 12))
|
||
|
|
#define EFLAG_VXSOFT (1 << (31 - 21))
|
||
|
|
#define EFLAG_VXSQRT (1 << (31 - 22))
|
||
|
|
#define EFLAG_VXCVI (1 << (31 - 23))
|