///////////////////////////////////////////////////////////////////////// // $Id: fpu.cc,v 1.30 2007-12-23 17:21:27 sshwarts Exp $ ///////////////////////////////////////////////////////////////////////// // // Copyright (c) 2003 Stanislav Shwartsman // Written by Stanislav Shwartsman [sshwarts at sourceforge net] // // This 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 of the License, or (at your option) any later version. // // This 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 this library; if not, write to the Free Software // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA // ///////////////////////////////////////////////////////////////////////// #define NEED_CPU_REG_SHORTCUTS 1 #include "bochs.h" #include "cpu/cpu.h" #define LOG_THIS BX_CPU_THIS_PTR #include "iodev/iodev.h" #define UPDATE_LAST_OPCODE 1 #define CHECK_PENDING_EXCEPTIONS 1 #if BX_SUPPORT_FPU void BX_CPU_C::prepareFPU(bxInstruction_c *i, bx_bool check_pending_exceptions, bx_bool update_last_instruction) { if (BX_CPU_THIS_PTR cr0.get_EM() || BX_CPU_THIS_PTR cr0.get_TS()) exception(BX_NM_EXCEPTION, 0, 0); if (check_pending_exceptions) BX_CPU_THIS_PTR FPU_check_pending_exceptions(); if (update_last_instruction) { BX_CPU_THIS_PTR the_i387.foo = ((Bit32u)(i->b1()) << 8) | (Bit32u)(i->modrm()) & 0x7ff; BX_CPU_THIS_PTR the_i387.fcs = BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].selector.value; BX_CPU_THIS_PTR the_i387.fip = BX_CPU_THIS_PTR prev_rip; if (! i->modC0()) { BX_CPU_THIS_PTR the_i387.fds = BX_CPU_THIS_PTR sregs[i->seg()].selector.value; BX_CPU_THIS_PTR the_i387.fdp = RMAddr(i); } else { BX_CPU_THIS_PTR the_i387.fds = BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].selector.value; BX_CPU_THIS_PTR the_i387.fdp = 0; } } } void BX_CPU_C::FPU_check_pending_exceptions(void) { if(BX_CPU_THIS_PTR the_i387.get_partial_status() & FPU_SW_Summary) { // NE=1 selects the native or internal mode, which generates #MF, // which is an extension introduced with 80486. // NE=0 selects the original (backward compatible) FPU error // handling, which generates an IRQ 13 via the PIC chip. #if BX_CPU_LEVEL >= 4 if (BX_CPU_THIS_PTR cr0.get_NE() != 0) { exception(BX_MF_EXCEPTION, 0, 0); } else #endif { // MSDOS compatibility external interrupt (IRQ13) BX_INFO (("math_abort: MSDOS compatibility FPU exception")); DEV_pic_raise_irq(13); } } } int BX_CPU_C::fpu_save_environment(bxInstruction_c *i) { if (protected_mode()) /* Protected Mode */ { if (i->os32L() || i->os64L()) { Bit32u tmp; tmp = 0xffff0000 | BX_CPU_THIS_PTR the_i387.get_control_word(); write_virtual_dword(i->seg(), RMAddr(i), tmp); tmp = 0xffff0000 | BX_CPU_THIS_PTR the_i387.get_status_word(); write_virtual_dword(i->seg(), RMAddr(i) + 0x04, tmp); tmp = 0xffff0000 | BX_CPU_THIS_PTR the_i387.get_tag_word(); write_virtual_dword(i->seg(), RMAddr(i) + 0x08, tmp); tmp = (BX_CPU_THIS_PTR the_i387.fip) & 0xffffffff; write_virtual_dword(i->seg(), RMAddr(i) + 0x0c, tmp); tmp = (BX_CPU_THIS_PTR the_i387.fcs & 0xffff) | ((Bit32u)(BX_CPU_THIS_PTR the_i387.foo)) << 16; write_virtual_dword(i->seg(), RMAddr(i) + 0x10, tmp); tmp = (BX_CPU_THIS_PTR the_i387.fdp) & 0xffffffff; write_virtual_dword(i->seg(), RMAddr(i) + 0x14, tmp); tmp = 0xffff0000 | (BX_CPU_THIS_PTR the_i387.fds); write_virtual_dword(i->seg(), RMAddr(i) + 0x18, tmp); return 0x1c; } else /* Protected Mode - 16 bit */ { Bit16u tmp; tmp = BX_CPU_THIS_PTR the_i387.get_control_word(); write_virtual_word(i->seg(), RMAddr(i), tmp); tmp = BX_CPU_THIS_PTR the_i387.get_status_word(); write_virtual_word(i->seg(), RMAddr(i) + 0x02, tmp); tmp = BX_CPU_THIS_PTR the_i387.get_tag_word(); write_virtual_word(i->seg(), RMAddr(i) + 0x04, tmp); tmp = (BX_CPU_THIS_PTR the_i387.fip) & 0xffff; write_virtual_word(i->seg(), RMAddr(i) + 0x06, tmp); tmp = (BX_CPU_THIS_PTR the_i387.fcs); write_virtual_word(i->seg(), RMAddr(i) + 0x08, tmp); tmp = (BX_CPU_THIS_PTR the_i387.fdp) & 0xffff; write_virtual_word(i->seg(), RMAddr(i) + 0x0a, tmp); tmp = (BX_CPU_THIS_PTR the_i387.fds); write_virtual_word(i->seg(), RMAddr(i) + 0x0c, tmp); return 0x0e; } } else /* Real or V86 Mode */ { Bit32u fp_ip = ((Bit32u)(BX_CPU_THIS_PTR the_i387.fcs) << 4) + (Bit32u)(BX_CPU_THIS_PTR the_i387.fip); Bit32u fp_dp = ((Bit32u)(BX_CPU_THIS_PTR the_i387.fds) << 4) + (Bit32u)(BX_CPU_THIS_PTR the_i387.fdp); if (i->os32L() || i->os64L()) { Bit32u tmp; tmp = 0xffff0000 | BX_CPU_THIS_PTR the_i387.get_control_word(); write_virtual_dword(i->seg(), RMAddr(i), tmp); tmp = 0xffff0000 | BX_CPU_THIS_PTR the_i387.get_status_word(); write_virtual_dword(i->seg(), RMAddr(i) + 0x04, tmp); tmp = 0xffff0000 | BX_CPU_THIS_PTR the_i387.get_tag_word(); write_virtual_dword(i->seg(), RMAddr(i) + 0x08, tmp); tmp = 0xffff0000 | (fp_ip & 0xffff); write_virtual_dword(i->seg(), RMAddr(i) + 0x0c, tmp); tmp = ((fp_ip & 0xffff0000) >> 4) | (BX_CPU_THIS_PTR the_i387.foo & 0x7ff); write_virtual_dword(i->seg(), RMAddr(i) + 0x10, tmp); tmp = 0xffff0000 | (fp_dp & 0xffff); write_virtual_dword(i->seg(), RMAddr(i) + 0x14, tmp); tmp = (fp_dp & 0xffff0000) >> 4; write_virtual_dword(i->seg(), RMAddr(i) + 0x18, tmp); return 0x1c; } else /* Real or V86 Mode - 16 bit */ { Bit16u tmp; tmp = BX_CPU_THIS_PTR the_i387.get_control_word(); write_virtual_word(i->seg(), RMAddr(i), tmp); tmp = BX_CPU_THIS_PTR the_i387.get_status_word(); write_virtual_word(i->seg(), RMAddr(i) + 0x02, tmp); tmp = BX_CPU_THIS_PTR the_i387.get_tag_word(); write_virtual_word(i->seg(), RMAddr(i) + 0x04, tmp); tmp = fp_ip & 0xffff; write_virtual_word(i->seg(), RMAddr(i) + 0x06, tmp); tmp = (Bit16u)(((fp_ip & 0xf0000) >> 4) | (BX_CPU_THIS_PTR the_i387.foo & 0x7ff)); write_virtual_word(i->seg(), RMAddr(i) + 0x08, tmp); tmp = fp_dp & 0xffff; write_virtual_word(i->seg(), RMAddr(i) + 0x0a, tmp); tmp = (Bit16u)((fp_dp & 0xf0000) >> 4); write_virtual_word(i->seg(), RMAddr(i) + 0x0c, tmp); return 0x0e; } } } int BX_CPU_C::fpu_load_environment(bxInstruction_c *i) { int offset; if (protected_mode()) /* Protected Mode */ { if (i->os32L() || i->os64L()) { Bit32u tmp; tmp = read_virtual_dword(i->seg(), RMAddr(i)); BX_CPU_THIS_PTR the_i387.cwd = tmp & 0xffff; tmp = read_virtual_dword(i->seg(), RMAddr(i) + 0x04); BX_CPU_THIS_PTR the_i387.swd = tmp & 0xffff; BX_CPU_THIS_PTR the_i387.tos = (tmp >> 11) & 0x07; tmp = read_virtual_dword(i->seg(), RMAddr(i) + 0x08); BX_CPU_THIS_PTR the_i387.twd = tmp & 0xffff; tmp = read_virtual_dword(i->seg(), RMAddr(i) + 0x0c); BX_CPU_THIS_PTR the_i387.fip = tmp; tmp = read_virtual_dword(i->seg(), RMAddr(i) + 0x10); BX_CPU_THIS_PTR the_i387.fcs = tmp & 0xffff; BX_CPU_THIS_PTR the_i387.foo = (tmp >> 16) & 0x07ff; tmp = read_virtual_dword(i->seg(), RMAddr(i) + 0x14); BX_CPU_THIS_PTR the_i387.fdp = tmp; tmp = read_virtual_dword(i->seg(), RMAddr(i) + 0x18); BX_CPU_THIS_PTR the_i387.fds = tmp & 0xffff; offset = 0x1c; } else /* Protected Mode - 16 bit */ { Bit16u tmp; tmp = read_virtual_word(i->seg(), RMAddr(i)); BX_CPU_THIS_PTR the_i387.cwd = tmp; tmp = read_virtual_word(i->seg(), RMAddr(i) + 0x2); BX_CPU_THIS_PTR the_i387.swd = tmp; BX_CPU_THIS_PTR the_i387.tos = (tmp >> 11) & 0x07; tmp = read_virtual_word(i->seg(), RMAddr(i) + 0x04); BX_CPU_THIS_PTR the_i387.twd = tmp; tmp = read_virtual_word(i->seg(), RMAddr(i) + 0x06); BX_CPU_THIS_PTR the_i387.fip = tmp & 0xffff; tmp = read_virtual_word(i->seg(), RMAddr(i) + 0x08); BX_CPU_THIS_PTR the_i387.fcs = tmp; tmp = read_virtual_word(i->seg(), RMAddr(i) + 0x0a); BX_CPU_THIS_PTR the_i387.fdp = tmp & 0xffff; tmp = read_virtual_word(i->seg(), RMAddr(i) + 0x0c); BX_CPU_THIS_PTR the_i387.fds = tmp; /* opcode is defined to be zero */ BX_CPU_THIS_PTR the_i387.foo = 0; offset = 0x0e; } } else /* Real or V86 Mode */ { Bit32u fp_ip = 0, fp_dp = 0; if (i->os32L() || i->os64L()) { Bit32u tmp; tmp = read_virtual_dword(i->seg(), RMAddr(i)); BX_CPU_THIS_PTR the_i387.cwd = tmp & 0xffff; tmp = read_virtual_dword(i->seg(), RMAddr(i) + 0x04); BX_CPU_THIS_PTR the_i387.swd = tmp & 0xffff; BX_CPU_THIS_PTR the_i387.tos = (tmp >> 11) & 0x07; tmp = read_virtual_dword(i->seg(), RMAddr(i) + 0x08); BX_CPU_THIS_PTR the_i387.twd = tmp & 0xffff; tmp = read_virtual_dword(i->seg(), RMAddr(i) + 0x0c); fp_ip = tmp & 0xffff; tmp = read_virtual_dword(i->seg(), RMAddr(i) + 0x10); fp_ip = fp_ip | ((tmp & 0x0ffff000) << 4); BX_CPU_THIS_PTR the_i387.fip = fp_ip; BX_CPU_THIS_PTR the_i387.foo = tmp & 0x07ff; BX_CPU_THIS_PTR the_i387.fcs = 0; tmp = read_virtual_dword(i->seg(), RMAddr(i) + 0x14); fp_dp = tmp & 0xffff; tmp = read_virtual_dword(i->seg(), RMAddr(i) + 0x18); fp_dp = fp_dp | ((tmp & 0x0ffff000) << 4); BX_CPU_THIS_PTR the_i387.fdp = fp_dp; BX_CPU_THIS_PTR the_i387.fds = 0; offset = 0x1c; } else /* Real or V86 Mode - 16 bit */ { Bit16u tmp; tmp = read_virtual_word(i->seg(), RMAddr(i)); BX_CPU_THIS_PTR the_i387.cwd = tmp; tmp = read_virtual_word(i->seg(), RMAddr(i) + 0x2); BX_CPU_THIS_PTR the_i387.swd = tmp; BX_CPU_THIS_PTR the_i387.tos = (tmp >> 11) & 0x07; tmp = read_virtual_word(i->seg(), RMAddr(i) + 0x04); BX_CPU_THIS_PTR the_i387.twd = tmp; tmp = read_virtual_word(i->seg(), RMAddr(i) + 0x06); fp_ip = tmp & 0xffff; tmp = read_virtual_word(i->seg(), RMAddr(i) + 0x08); fp_ip = fp_ip | ((tmp & 0xf000) << 4); BX_CPU_THIS_PTR the_i387.fip = fp_ip; BX_CPU_THIS_PTR the_i387.foo = tmp & 0x07ff; BX_CPU_THIS_PTR the_i387.fcs = 0; tmp = read_virtual_word(i->seg(), RMAddr(i) + 0x0a); fp_dp = tmp & 0xffff; tmp = read_virtual_word(i->seg(), RMAddr(i) + 0x0c); fp_dp = fp_dp | ((tmp & 0xf000) << 4); BX_CPU_THIS_PTR the_i387.fdp = fp_dp; BX_CPU_THIS_PTR the_i387.fds = 0; offset = 0x0e; } } /* check for unmasked exceptions */ if (FPU_PARTIAL_STATUS & ~FPU_CONTROL_WORD & FPU_CW_Exceptions_Mask) { /* set the B and ES bits in the status-word */ FPU_PARTIAL_STATUS |= FPU_SW_Summary | FPU_SW_Backward; } else { /* clear the B and ES bits in the status-word */ FPU_PARTIAL_STATUS &= ~(FPU_SW_Summary | FPU_SW_Backward); } return offset; } #endif /* D9 /5 */ void BX_CPU_C::FLDCW(bxInstruction_c *i) { #if BX_SUPPORT_FPU BX_CPU_THIS_PTR prepareFPU(i, CHECK_PENDING_EXCEPTIONS, !UPDATE_LAST_OPCODE); Bit16u cwd = read_virtual_word(i->seg(), RMAddr(i)); FPU_CONTROL_WORD = cwd; /* check for unmasked exceptions */ if (FPU_PARTIAL_STATUS & ~FPU_CONTROL_WORD & FPU_CW_Exceptions_Mask) { /* set the B and ES bits in the status-word */ FPU_PARTIAL_STATUS |= FPU_SW_Summary | FPU_SW_Backward; } else { /* clear the B and ES bits in the status-word */ FPU_PARTIAL_STATUS &= ~(FPU_SW_Summary | FPU_SW_Backward); } #else BX_INFO(("FLDCW: required FPU, configure --enable-fpu")); #endif } /* D9 /7 */ void BX_CPU_C::FNSTCW(bxInstruction_c *i) { #if BX_SUPPORT_FPU BX_CPU_THIS_PTR prepareFPU(i, !CHECK_PENDING_EXCEPTIONS, !UPDATE_LAST_OPCODE); Bit16u cwd = BX_CPU_THIS_PTR the_i387.get_control_word(); write_virtual_word(i->seg(), RMAddr(i), cwd); #else BX_INFO(("FNSTCW: required FPU, configure --enable-fpu")); #endif } /* DD /7 */ void BX_CPU_C::FNSTSW(bxInstruction_c *i) { #if BX_SUPPORT_FPU BX_CPU_THIS_PTR prepareFPU(i, !CHECK_PENDING_EXCEPTIONS, !UPDATE_LAST_OPCODE); Bit16u swd = BX_CPU_THIS_PTR the_i387.get_status_word(); write_virtual_word(i->seg(), RMAddr(i), swd); #else BX_INFO(("FNSTSW: required FPU, configure --enable-fpu")); #endif } /* DF E0 */ void BX_CPU_C::FNSTSW_AX(bxInstruction_c *i) { #if BX_SUPPORT_FPU BX_CPU_THIS_PTR prepareFPU(i, !CHECK_PENDING_EXCEPTIONS, !UPDATE_LAST_OPCODE); AX = BX_CPU_THIS_PTR the_i387.get_status_word(); #else BX_INFO(("FNSTSW_AX: required FPU, configure --enable-fpu")); #endif } /* DD /4 */ void BX_CPU_C::FRSTOR(bxInstruction_c *i) { #if BX_SUPPORT_FPU BX_CPU_THIS_PTR prepareFPU(i, CHECK_PENDING_EXCEPTIONS, !UPDATE_LAST_OPCODE); int offset = fpu_load_environment(i); /* read all registers in stack order. */ for(int n=0;n<8;n++) { floatx80 tmp; // read register only if its tag is not empty if (! IS_TAG_EMPTY(n)) { read_virtual_tword(i->seg(), RMAddr(i) + offset + n*10, &tmp); BX_WRITE_FPU_REG(tmp, n); } } #else BX_INFO(("FRSTOR: required FPU, configure --enable-fpu")); #endif } /* DD /6 */ void BX_CPU_C::FNSAVE(bxInstruction_c *i) { #if BX_SUPPORT_FPU BX_CPU_THIS_PTR prepareFPU(i, !CHECK_PENDING_EXCEPTIONS, !UPDATE_LAST_OPCODE); int offset = fpu_save_environment(i); /* save all registers in stack order. */ for(int n=0;n<8;n++) { floatx80 stn = BX_READ_FPU_REG(n); write_virtual_tword(i->seg(), RMAddr(i) + offset + n*10, &stn); } BX_CPU_THIS_PTR the_i387.init(); #else BX_INFO(("FNSAVE: required FPU, configure --enable-fpu")); #endif } /* 9B E2 */ void BX_CPU_C::FNCLEX(bxInstruction_c *i) { #if BX_SUPPORT_FPU BX_CPU_THIS_PTR prepareFPU(i, !CHECK_PENDING_EXCEPTIONS, !UPDATE_LAST_OPCODE); FPU_PARTIAL_STATUS &= ~(FPU_SW_Backward|FPU_SW_Summary|FPU_SW_Stack_Fault|FPU_SW_Precision| FPU_SW_Underflow|FPU_SW_Overflow|FPU_SW_Zero_Div|FPU_SW_Denormal_Op| FPU_SW_Invalid); // do not update last fpu instruction pointer #else BX_INFO(("FNCLEX: required FPU, configure --enable-fpu")); #endif } /* DB E3 */ void BX_CPU_C::FNINIT(bxInstruction_c *i) { #if BX_SUPPORT_FPU BX_CPU_THIS_PTR prepareFPU(i, !CHECK_PENDING_EXCEPTIONS, !UPDATE_LAST_OPCODE); BX_CPU_THIS_PTR the_i387.init(); #else BX_INFO(("FNINIT: required FPU, configure --enable-fpu")); #endif } /* D9 /4 */ void BX_CPU_C::FLDENV(bxInstruction_c *i) { #if BX_SUPPORT_FPU BX_CPU_THIS_PTR prepareFPU(i, CHECK_PENDING_EXCEPTIONS, !UPDATE_LAST_OPCODE); fpu_load_environment(i); #else BX_INFO(("FLDENV: required FPU, configure --enable-fpu")); #endif } /* D9 /6 */ void BX_CPU_C::FNSTENV(bxInstruction_c *i) { #if BX_SUPPORT_FPU BX_CPU_THIS_PTR prepareFPU(i, !CHECK_PENDING_EXCEPTIONS, !UPDATE_LAST_OPCODE); fpu_save_environment(i); /* mask all floating point exceptions */ FPU_CONTROL_WORD |= FPU_CW_Exceptions_Mask; /* clear the B and ES bits in the status word */ FPU_PARTIAL_STATUS &= ~(FPU_SW_Backward|FPU_SW_Summary); #else BX_INFO(("FNSTENV: required FPU, configure --enable-fpu")); #endif } /* D9 D0 */ void BX_CPU_C::FNOP(bxInstruction_c *i) { #if BX_SUPPORT_FPU BX_CPU_THIS_PTR prepareFPU(i, CHECK_PENDING_EXCEPTIONS, !UPDATE_LAST_OPCODE); // Perform no FPU operation. This instruction takes up space in the // instruction stream but does not affect the FPU or machine // context, except the EIP register. #else BX_INFO(("FNOP: required FPU, configure --enable-fpu")); #endif } void BX_CPU_C::FPLEGACY(bxInstruction_c *i) { #if BX_SUPPORT_FPU BX_CPU_THIS_PTR prepareFPU(i, !CHECK_PENDING_EXCEPTIONS, !UPDATE_LAST_OPCODE); // FPU performs no specific operation and no internal x87 states // are affected #else BX_INFO(("legacy FPU opcodes: required FPU, configure --enable-fpu")); #endif } #if BX_SUPPORT_FPU #include void BX_CPU_C::print_state_FPU() { static double scale_factor = pow(2.0, -63.0); Bit32u reg; reg = BX_CPU_THIS_PTR the_i387.get_control_word(); fprintf(stderr, "control word: 0x%04x\n", reg); reg = BX_CPU_THIS_PTR the_i387.get_status_word(); fprintf(stderr, "status word: 0x%04x\n", reg); fprintf(stderr, " TOS : %d\n", FPU_TOS&7); reg = BX_CPU_THIS_PTR the_i387.get_tag_word(); fprintf(stderr, "tag word: 0x%04x\n", reg); reg = BX_CPU_THIS_PTR the_i387.foo; fprintf(stderr, "operand: 0x%04x\n", reg); reg = BX_CPU_THIS_PTR the_i387.fip & 0xffffffff; fprintf(stderr, "fip: 0x%08x\n", reg); reg = BX_CPU_THIS_PTR the_i387.fcs; fprintf(stderr, "fcs: 0x%04x\n", reg); reg = BX_CPU_THIS_PTR the_i387.fdp & 0xffffffff; fprintf(stderr, "fdp: 0x%08x\n", reg); reg = BX_CPU_THIS_PTR the_i387.fds; fprintf(stderr, "fds: 0x%04x\n", reg); // print stack too int tos = FPU_TOS & 7; for (int i=0; i<8; i++) { const floatx80 &fp = BX_FPU_REG(i); double f = pow(2.0, ((0x7fff & fp.exp) - 0x3fff)); if (fp.exp & 0x8000) f = -f; #ifdef _MSC_VER f *= (double)(signed __int64)(fp.fraction>>1) * scale_factor * 2; #else f *= fp.fraction*scale_factor; #endif fprintf(stderr, "%sFPR%d(%c): %.10f (raw 0x%04x:%08lx%08lx)\n", i==tos?"=>":" ", i, "v0s?"[BX_CPU_THIS_PTR the_i387.FPU_gettagi((i-tos)&7)], f, fp.exp & 0xffff, fp.fraction >> 32, fp.fraction & 0xffffffff); } } #endif