From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 16 Apr 2005 15:20:36 -0700 Subject: Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip! --- arch/arm26/nwfpe/fpa11_cprt.c | 289 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 289 insertions(+) create mode 100644 arch/arm26/nwfpe/fpa11_cprt.c (limited to 'arch/arm26/nwfpe/fpa11_cprt.c') diff --git a/arch/arm26/nwfpe/fpa11_cprt.c b/arch/arm26/nwfpe/fpa11_cprt.c new file mode 100644 index 00000000000..a201076c1f1 --- /dev/null +++ b/arch/arm26/nwfpe/fpa11_cprt.c @@ -0,0 +1,289 @@ +/* + NetWinder Floating Point Emulator + (c) Rebel.COM, 1998,1999 + (c) Philip Blundell, 1999 + + Direct questions, comments to Scott Bambrough + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program 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 General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. +*/ + +#include "fpa11.h" +#include "milieu.h" +#include "softfloat.h" +#include "fpopcode.h" +#include "fpa11.inl" +#include "fpmodule.h" +#include "fpmodule.inl" + +extern flag floatx80_is_nan(floatx80); +extern flag float64_is_nan( float64); +extern flag float32_is_nan( float32); + +void SetRoundingMode(const unsigned int opcode); + +unsigned int PerformFLT(const unsigned int opcode); +unsigned int PerformFIX(const unsigned int opcode); + +static unsigned int +PerformComparison(const unsigned int opcode); + +unsigned int EmulateCPRT(const unsigned int opcode) +{ + unsigned int nRc = 1; + + //printk("EmulateCPRT(0x%08x)\n",opcode); + + if (opcode & 0x800000) + { + /* This is some variant of a comparison (PerformComparison will + sort out which one). Since most of the other CPRT + instructions are oddball cases of some sort or other it makes + sense to pull this out into a fast path. */ + return PerformComparison(opcode); + } + + /* Hint to GCC that we'd like a jump table rather than a load of CMPs */ + switch ((opcode & 0x700000) >> 20) + { + case FLT_CODE >> 20: nRc = PerformFLT(opcode); break; + case FIX_CODE >> 20: nRc = PerformFIX(opcode); break; + + case WFS_CODE >> 20: writeFPSR(readRegister(getRd(opcode))); break; + case RFS_CODE >> 20: writeRegister(getRd(opcode),readFPSR()); break; + +#if 0 /* We currently have no use for the FPCR, so there's no point + in emulating it. */ + case WFC_CODE >> 20: writeFPCR(readRegister(getRd(opcode))); + case RFC_CODE >> 20: writeRegister(getRd(opcode),readFPCR()); break; +#endif + + default: nRc = 0; + } + + return nRc; +} + +unsigned int PerformFLT(const unsigned int opcode) +{ + FPA11 *fpa11 = GET_FPA11(); + + unsigned int nRc = 1; + SetRoundingMode(opcode); + + switch (opcode & MASK_ROUNDING_PRECISION) + { + case ROUND_SINGLE: + { + fpa11->fType[getFn(opcode)] = typeSingle; + fpa11->fpreg[getFn(opcode)].fSingle = + int32_to_float32(readRegister(getRd(opcode))); + } + break; + + case ROUND_DOUBLE: + { + fpa11->fType[getFn(opcode)] = typeDouble; + fpa11->fpreg[getFn(opcode)].fDouble = + int32_to_float64(readRegister(getRd(opcode))); + } + break; + + case ROUND_EXTENDED: + { + fpa11->fType[getFn(opcode)] = typeExtended; + fpa11->fpreg[getFn(opcode)].fExtended = + int32_to_floatx80(readRegister(getRd(opcode))); + } + break; + + default: nRc = 0; + } + + return nRc; +} + +unsigned int PerformFIX(const unsigned int opcode) +{ + FPA11 *fpa11 = GET_FPA11(); + unsigned int nRc = 1; + unsigned int Fn = getFm(opcode); + + SetRoundingMode(opcode); + + switch (fpa11->fType[Fn]) + { + case typeSingle: + { + writeRegister(getRd(opcode), + float32_to_int32(fpa11->fpreg[Fn].fSingle)); + } + break; + + case typeDouble: + { + writeRegister(getRd(opcode), + float64_to_int32(fpa11->fpreg[Fn].fDouble)); + } + break; + + case typeExtended: + { + writeRegister(getRd(opcode), + floatx80_to_int32(fpa11->fpreg[Fn].fExtended)); + } + break; + + default: nRc = 0; + } + + return nRc; +} + + +static unsigned int __inline__ +PerformComparisonOperation(floatx80 Fn, floatx80 Fm) +{ + unsigned int flags = 0; + + /* test for less than condition */ + if (floatx80_lt(Fn,Fm)) + { + flags |= CC_NEGATIVE; + } + + /* test for equal condition */ + if (floatx80_eq(Fn,Fm)) + { + flags |= CC_ZERO; + } + + /* test for greater than or equal condition */ + if (floatx80_lt(Fm,Fn)) + { + flags |= CC_CARRY; + } + + writeConditionCodes(flags); + return 1; +} + +/* This instruction sets the flags N, Z, C, V in the FPSR. */ + +static unsigned int PerformComparison(const unsigned int opcode) +{ + FPA11 *fpa11 = GET_FPA11(); + unsigned int Fn, Fm; + floatx80 rFn, rFm; + int e_flag = opcode & 0x400000; /* 1 if CxFE */ + int n_flag = opcode & 0x200000; /* 1 if CNxx */ + unsigned int flags = 0; + + //printk("PerformComparison(0x%08x)\n",opcode); + + Fn = getFn(opcode); + Fm = getFm(opcode); + + /* Check for unordered condition and convert all operands to 80-bit + format. + ?? Might be some mileage in avoiding this conversion if possible. + Eg, if both operands are 32-bit, detect this and do a 32-bit + comparison (cheaper than an 80-bit one). */ + switch (fpa11->fType[Fn]) + { + case typeSingle: + //printk("single.\n"); + if (float32_is_nan(fpa11->fpreg[Fn].fSingle)) + goto unordered; + rFn = float32_to_floatx80(fpa11->fpreg[Fn].fSingle); + break; + + case typeDouble: + //printk("double.\n"); + if (float64_is_nan(fpa11->fpreg[Fn].fDouble)) + goto unordered; + rFn = float64_to_floatx80(fpa11->fpreg[Fn].fDouble); + break; + + case typeExtended: + //printk("extended.\n"); + if (floatx80_is_nan(fpa11->fpreg[Fn].fExtended)) + goto unordered; + rFn = fpa11->fpreg[Fn].fExtended; + break; + + default: return 0; + } + + if (CONSTANT_FM(opcode)) + { + //printk("Fm is a constant: #%d.\n",Fm); + rFm = getExtendedConstant(Fm); + if (floatx80_is_nan(rFm)) + goto unordered; + } + else + { + //printk("Fm = r%d which contains a ",Fm); + switch (fpa11->fType[Fm]) + { + case typeSingle: + //printk("single.\n"); + if (float32_is_nan(fpa11->fpreg[Fm].fSingle)) + goto unordered; + rFm = float32_to_floatx80(fpa11->fpreg[Fm].fSingle); + break; + + case typeDouble: + //printk("double.\n"); + if (float64_is_nan(fpa11->fpreg[Fm].fDouble)) + goto unordered; + rFm = float64_to_floatx80(fpa11->fpreg[Fm].fDouble); + break; + + case typeExtended: + //printk("extended.\n"); + if (floatx80_is_nan(fpa11->fpreg[Fm].fExtended)) + goto unordered; + rFm = fpa11->fpreg[Fm].fExtended; + break; + + default: return 0; + } + } + + if (n_flag) + { + rFm.high ^= 0x8000; + } + + return PerformComparisonOperation(rFn,rFm); + + unordered: + /* ?? The FPA data sheet is pretty vague about this, in particular + about whether the non-E comparisons can ever raise exceptions. + This implementation is based on a combination of what it says in + the data sheet, observation of how the Acorn emulator actually + behaves (and how programs expect it to) and guesswork. */ + flags |= CC_OVERFLOW; + flags &= ~(CC_ZERO | CC_NEGATIVE); + + if (BIT_AC & readFPSR()) flags |= CC_CARRY; + + if (e_flag) float_raise(float_flag_invalid); + + writeConditionCodes(flags); + return 1; +} -- cgit v1.2.3