patch-2.2.18 linux/arch/arm/nwfpe/fpopcode.c

• Lines: 165
• Date: Fri Sep 15 23:28:37 2000
• Orig file: v2.2.17/arch/arm/nwfpe/fpopcode.c
• Orig date: Thu Jan 1 01:00:00 1970

diff -u --new-file --recursive --exclude-from /usr/src/exclude v2.2.17/arch/arm/nwfpe/fpopcode.c linux/arch/arm/nwfpe/fpopcode.c
@@ -0,0 +1,164 @@
+/*
+    NetWinder Floating Point Emulator
+    (c) Corel Computer Corporation, 1998
+
+    Direct questions, comments to Scott Bambrough <scottb@corelcomputer.com>
+
+    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 "config.h"
+#include "softfloat.h"
+#include "fpopcode.h"
+#include "fpsr.h"
+#include "fpa11.h"
+#include "fpmodule.h"
+#include "fpmodule.inl"
+
+static floatx80 floatx80Constant[] = {
+  { 0x0000, 0x0000000000000000ULL},	/* extended 0.0 */
+  { 0x3fff, 0x8000000000000000ULL},	/* extended 1.0 */
+  { 0x4000, 0x8000000000000000ULL},	/* extended 2.0 */
+  { 0x4000, 0xc000000000000000ULL},	/* extended 3.0 */
+  { 0x4001, 0x8000000000000000ULL},	/* extended 4.0 */
+  { 0x4001, 0xa000000000000000ULL},	/* extended 5.0 */
+  { 0x3ffe, 0x8000000000000000ULL},	/* extended 0.5 */
+  { 0x4002, 0xa000000000000000ULL}	/* extended 10.0 */
+};  
+
+static float64 float64Constant[] = {
+  0x0000000000000000ULL,		/* double 0.0 */
+  0x3ff0000000000000ULL,		/* double 1.0 */
+  0x4000000000000000ULL,		/* double 2.0 */
+  0x4008000000000000ULL,		/* double 3.0 */
+  0x4010000000000000ULL,		/* double 4.0 */
+  0x4014000000000000ULL,		/* double 5.0 */
+  0x3fe0000000000000ULL,		/* double 0.5 */
+  0x4024000000000000ULL			/* double 10.0 */
+};  
+
+static float32 float32Constant[] = {
+  0x00000000,				/* single 0.0 */
+  0x3f800000,				/* single 1.0 */
+  0x40000000,				/* single 2.0 */
+  0x40400000,				/* single 3.0 */
+  0x40800000,				/* single 4.0 */
+  0x40a00000,				/* single 5.0 */
+  0x3f000000,				/* single 0.5 */
+  0x41200000				/* single 10.0 */
+};  
+
+floatx80 getExtendedConstant(const unsigned int nIndex)
+{
+   return floatx80Constant[nIndex];
+} 
+
+float64 getDoubleConstant(const unsigned int nIndex)
+{
+   return float64Constant[nIndex];
+} 
+
+float32 getSingleConstant(const unsigned int nIndex)
+{
+   return float32Constant[nIndex];
+} 
+
+unsigned int getTransferLength(const unsigned int opcode)
+{
+  unsigned int nRc;
+  
+  switch (opcode & MASK_TRANSFER_LENGTH)
+  {
+    case 0x00000000: nRc = 1; break; /* single precision */
+    case 0x00008000: nRc = 2; break; /* double precision */
+    case 0x00400000: nRc = 3; break; /* extended precision */
+    default: nRc = 0;
+  }
+  
+  return(nRc);
+}
+
+unsigned int getRegisterCount(const unsigned int opcode)
+{
+  unsigned int nRc;
+  
+  switch (opcode & MASK_REGISTER_COUNT)
+  {
+    case 0x00000000: nRc = 4; break;
+    case 0x00008000: nRc = 1; break;
+    case 0x00400000: nRc = 2; break;
+    case 0x00408000: nRc = 3; break;
+    default: nRc = 0;
+  }
+  
+  return(nRc);
+}
+
+unsigned int getRoundingPrecision(const unsigned int opcode)
+{
+  unsigned int nRc;
+  
+  switch (opcode & MASK_ROUNDING_PRECISION)
+  {
+    case 0x00000000: nRc = 1; break;
+    case 0x00000080: nRc = 2; break;
+    case 0x00080000: nRc = 3; break;
+    default: nRc = 0;
+  }
+  
+  return(nRc);
+}
+
+unsigned int getDestinationSize(const unsigned int opcode)
+{
+  unsigned int nRc;
+  
+  switch (opcode & MASK_DESTINATION_SIZE)
+  {
+    case 0x00000000: nRc = typeSingle; break;
+    case 0x00000080: nRc = typeDouble; break;
+    case 0x00080000: nRc = typeExtended; break;
+    default: nRc = typeNone;
+  }
+  
+  return(nRc);
+}
+
+/* contition code lookup table
+ index into the table is test code: EQ, NE, ... LT, GT, AL, NV
+ bit position in short is condition code: NZCV */
+unsigned short aCC[16] = {
+    0xF0F0, // EQ == Z set
+    0x0F0F, // NE
+    0xCCCC, // CS == C set
+    0x3333, // CC
+    0xFF00, // MI == N set
+    0x00FF, // PL
+    0xAAAA, // VS == V set
+    0x5555, // VC
+    0x0C0C, // HI == C set && Z clear
+    0xF3F3, // LS == C clear || Z set
+    0xAA55, // GE == (N==V)
+    0x55AA, // LT == (N!=V)
+    0x0A05, // GT == (!Z && (N==V))
+    0xF5FA, // LE == (Z || (N!=V))
+    0xFFFF, // AL always
+    0 // NV
+};
+
+unsigned int checkCondition(const unsigned int opcode, const unsigned int ccodes)
+{
+  return (aCC[opcode>>28] >> (ccodes>>28)) & 1;
+}