| /* vax_cmode.c: VAX compatibility mode | |
| Copyright (c) 2004-2008, Robert M Supnik | |
| Permission is hereby granted, free of charge, to any person obtaining a | |
| copy of this software and associated documentation files (the "Software"), | |
| to deal in the Software without restriction, including without limitation | |
| the rights to use, copy, modify, merge, publish, distribute, sublicense, | |
| and/or sell copies of the Software, and to permit persons to whom the | |
| Software is furnished to do so, subject to the following conditions: | |
| The above copyright notice and this permission notice shall be included in | |
| all copies or substantial portions of the Software. | |
| THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
| IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
| FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL | |
| ROBERT M SUPNIK BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER | |
| IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN | |
| CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. | |
| Except as contained in this notice, the name of Robert M Supnik shall not be | |
| used in advertising or otherwise to promote the sale, use or other dealings | |
| in this Software without prior written authorization from Robert M Supnik. | |
| On a full VAX, this module implements PDP-11 compatibility mode. | |
| On a subset VAX, this module forces a fault if REI attempts to set PSL<cm>. | |
| 28-May-08 RMS Inlined physical memory routines | |
| 25-Jan-08 RMS Fixed declaration (Mark Pizzolato) | |
| 03-May-06 RMS Fixed omission of SXT | |
| Fixed order of operand fetching in XOR | |
| 24-Aug-04 RMS Cloned from PDP-11 CPU | |
| In compatibility mode, the Istream prefetch mechanism is not used. The | |
| prefetcher will be explicitly resynchronized through intexc on any exit | |
| from compatibility mode. | |
| */ | |
| #include "vax_defs.h" | |
| #if defined (FULL_VAX) | |
| #define RdMemB(a) Read (a, L_BYTE, RA) | |
| #define RdMemMB(a) Read (a, L_BYTE, WA) | |
| #define WrMemB(d,a) Write (a, d, L_BYTE, WA) | |
| #define BRANCH_F(x) CMODE_JUMP ((PC + (((x) + (x)) & BMASK)) & WMASK) | |
| #define BRANCH_B(x) CMODE_JUMP ((PC + (((x) + (x)) | 0177400)) & WMASK) | |
| #define CC_XOR_NV(x) ((((x) & CC_N) != 0) ^ (((x) & CC_V) != 0)) | |
| #define CC_XOR_NC(x) ((((x) & CC_N) != 0) ^ (((x) & CC_C) != 0)) | |
| extern int32 R[16]; | |
| extern int32 PSL; | |
| extern int32 trpirq; | |
| extern int32 p1; | |
| extern int32 fault_PC; | |
| extern int32 recq[]; /* recovery queue */ | |
| extern int32 recqptr; /* recq pointer */ | |
| extern int32 pcq[]; | |
| extern int32 pcq_p; | |
| extern int32 ibcnt, ppc; | |
| extern int32 sim_interval; | |
| extern uint32 sim_brk_summ; | |
| extern jmp_buf save_env; | |
| int32 GeteaB (int32 spec); | |
| int32 GeteaW (int32 spec); | |
| int32 RdMemW (int32 a); | |
| int32 RdMemMW (int32 a); | |
| void WrMemW (int32 d, int32 a); | |
| int32 RdRegB (int32 rn); | |
| int32 RdRegW (int32 rn); | |
| void WrRegB (int32 val, int32 rn); | |
| void WrRegW (int32 val, int32 rn); | |
| /* Validate PSL for compatibility mode */ | |
| t_bool BadCmPSL (int32 newpsl) | |
| { | |
| if ((newpsl & (PSL_FPD|PSL_IS|PSL_CUR|PSL_PRV|PSL_IPL)) != | |
| ((USER << PSL_V_CUR) | (USER << PSL_V_PRV))) | |
| return TRUE; | |
| else return FALSE; | |
| } | |
| /* Compatibility mode execution */ | |
| int32 op_cmode (int32 cc) | |
| { | |
| int32 IR, srcspec, dstspec, srcreg, dstreg, ea; | |
| int32 i, t, src, src2, dst, sign, oc; | |
| int32 acc = ACC_MASK (USER); | |
| PC = PC & WMASK; /* PC must be 16b */ | |
| if (sim_brk_summ && sim_brk_test (PC, SWMASK ('E'))) { /* breakpoint? */ | |
| ABORT (STOP_IBKPT); /* stop simulation */ | |
| } | |
| sim_interval = sim_interval - 1; /* count instr */ | |
| IR = RdMemW (PC); /* fetch instruction */ | |
| PC = (PC + 2) & WMASK; /* incr PC, mod 65k */ | |
| srcspec = (IR >> 6) & 077; /* src, dst specs */ | |
| dstspec = IR & 077; | |
| srcreg = (srcspec <= 07); /* src, dst = rmode? */ | |
| dstreg = (dstspec <= 07); | |
| switch ((IR >> 12) & 017) { /* decode IR<15:12> */ | |
| /* Opcode 0: no operands, specials, branches, JSR, SOPs */ | |
| case 000: /* 00xxxx */ | |
| switch ((IR >> 6) & 077) { /* decode IR<11:6> */ | |
| case 000: /* 0000xx */ | |
| switch (IR) { /* decode IR<5:0> */ | |
| case 3: /* BPT */ | |
| CMODE_FAULT (CMODE_BPT); | |
| break; | |
| case 4: /* IOT */ | |
| CMODE_FAULT (CMODE_IOT); | |
| break; | |
| case 2: /* RTI */ | |
| case 6: /* RTT */ | |
| src = RdMemW (R[6] & WMASK); /* new PC */ | |
| src2 = RdMemW ((R[6] + 2) & WMASK); /* new PSW */ | |
| R[6] = (R[6] + 4) & WMASK; | |
| cc = src2 & CC_MASK; /* update cc, T */ | |
| if (src2 & PSW_T) | |
| PSL = PSL | PSW_T; | |
| else PSL = PSL & ~PSW_T; | |
| CMODE_JUMP (src); /* update PC */ | |
| break; | |
| default: /* undefined */ | |
| CMODE_FAULT (CMODE_RSVI); | |
| break; | |
| } /* end switch IR */ | |
| break; /* end case 0000xx */ | |
| case 001: /* JMP */ | |
| if (dstreg) /* mode 0 illegal */ | |
| CMODE_FAULT (CMODE_ILLI); | |
| else { | |
| CMODE_JUMP (GeteaW (dstspec)); | |
| } | |
| break; | |
| case 002: /* 0002xx */ | |
| if (IR < 000210) { /* RTS */ | |
| dstspec = dstspec & 07; | |
| if (dstspec != 7) { /* PC <- r */ | |
| CMODE_JUMP (RdRegW (dstspec)); | |
| } | |
| dst = RdMemW (R[6]); /* t <- (sp)+ */ | |
| R[6] = (R[6] + 2) & WMASK; | |
| WrRegW (dst, dstspec); /* r <- t */ | |
| break; /* end if RTS */ | |
| } | |
| if (IR < 000240) { /* [210:237] */ | |
| CMODE_FAULT (CMODE_RSVI); | |
| break; | |
| } | |
| if (IR < 000260) /* clear CC */ | |
| cc = cc & ~(IR & CC_MASK); | |
| else cc = cc | (IR & CC_MASK); /* set CC */ | |
| break; | |
| case 003: /* SWAB */ | |
| if (dstreg) | |
| src = RdRegW (dstspec); | |
| else src = RdMemMW (ea = GeteaW (dstspec)); | |
| dst = ((src & BMASK) << 8) | ((src >> 8) & BMASK); | |
| if (dstreg) | |
| WrRegW (dst, dstspec); | |
| else WrMemW (dst, ea); | |
| CC_IIZZ_B ((dst & BMASK)); | |
| break; | |
| case 004: case 005: /* BR */ | |
| BRANCH_F (IR); | |
| break; | |
| case 006: case 007: /* BR */ | |
| BRANCH_B (IR); | |
| break; | |
| case 010: case 011: /* BNE */ | |
| if ((cc & CC_Z) == 0) { | |
| BRANCH_F (IR); | |
| } | |
| break; | |
| case 012: case 013: /* BNE */ | |
| if ((cc & CC_Z) == 0) { | |
| BRANCH_B (IR); | |
| } | |
| break; | |
| case 014: case 015: /* BEQ */ | |
| if (cc & CC_Z) { | |
| BRANCH_F (IR); | |
| } | |
| break; | |
| case 016: case 017: /* BEQ */ | |
| if (cc & CC_Z) { | |
| BRANCH_B (IR); | |
| } | |
| break; | |
| case 020: case 021: /* BGE */ | |
| if (CC_XOR_NV (cc) == 0) { | |
| BRANCH_F (IR); | |
| } | |
| break; | |
| case 022: case 023: /* BGE */ | |
| if (CC_XOR_NV (cc) == 0) { | |
| BRANCH_B (IR); | |
| } | |
| break; | |
| case 024: case 025: /* BLT */ | |
| if (CC_XOR_NV (cc)) { | |
| BRANCH_F (IR); | |
| } | |
| break; | |
| case 026: case 027: /* BLT */ | |
| if (CC_XOR_NV (cc)) { | |
| BRANCH_B (IR); | |
| } | |
| break; | |
| case 030: case 031: /* BGT */ | |
| if (((cc & CC_Z) || CC_XOR_NV (cc)) == 0) { | |
| BRANCH_F (IR); | |
| } | |
| break; | |
| case 032: case 033: /* BGT */ | |
| if (((cc & CC_Z) || CC_XOR_NV (cc)) == 0) { | |
| BRANCH_B (IR); | |
| } | |
| break; | |
| case 034: case 035: /* BLE */ | |
| if ((cc & CC_Z) || CC_XOR_NV (cc)) { | |
| BRANCH_F (IR); | |
| } | |
| break; | |
| case 036: case 037: /* BLE */ | |
| if ((cc & CC_Z) || CC_XOR_NV (cc)) { | |
| BRANCH_B (IR); | |
| } | |
| break; | |
| case 040: case 041: case 042: case 043: /* JSR */ | |
| case 044: case 045: case 046: case 047: | |
| if (dstreg) { /* mode 0 illegal */ | |
| CMODE_FAULT (CMODE_ILLI); | |
| } | |
| else { | |
| srcspec = srcspec & 07; /* get reg num */ | |
| dst = GeteaW (dstspec); /* get dst addr */ | |
| src = RdRegW (srcspec); /* get src reg */ | |
| WrMemW (src, (R[6] - 2) & WMASK); /* -(sp) <- r */ | |
| R[6] = (R[6] - 2) & WMASK; | |
| if (srcspec != 7) /* r <- PC */ | |
| WrRegW (PC, srcspec); | |
| CMODE_JUMP (dst); /* PC <- dst */ | |
| } | |
| break; /* end JSR */ | |
| case 050: /* CLR */ | |
| if (dstreg) | |
| WrRegW (0, dstspec); | |
| else WrMemW (0, GeteaW (dstspec)); | |
| cc = CC_Z; | |
| break; | |
| case 051: /* COM */ | |
| if (dstreg) | |
| src = RdRegW (dstspec); | |
| else src = RdMemMW (ea = GeteaW (dstspec)); | |
| dst = src ^ WMASK; | |
| if (dstreg) | |
| WrRegW (dst, dstspec); | |
| else WrMemW (dst, ea); | |
| CC_IIZZ_W (dst); | |
| cc = cc | CC_C; | |
| break; | |
| case 052: /* INC */ | |
| if (dstreg) | |
| src = RdRegW (dstspec); | |
| else src = RdMemMW (ea = GeteaW (dstspec)); | |
| dst = (src + 1) & WMASK; | |
| if (dstreg) | |
| WrRegW (dst, dstspec); | |
| else WrMemW (dst, ea); | |
| CC_IIZP_W (dst); | |
| if (dst == 0100000) | |
| cc = cc | CC_V; | |
| break; | |
| case 053: /* DEC */ | |
| if (dstreg) | |
| src = RdRegW (dstspec); | |
| else src = RdMemMW (ea = GeteaW (dstspec)); | |
| dst = (src - 1) & WMASK; | |
| if (dstreg) | |
| WrRegW (dst, dstspec); | |
| else WrMemW (dst, ea); | |
| CC_IIZP_W (dst); | |
| if (dst == 077777) | |
| cc = cc | CC_V; | |
| break; | |
| case 054: /* NEG */ | |
| if (dstreg) | |
| src = RdRegW (dstspec); | |
| else src = RdMemMW (ea = GeteaW (dstspec)); | |
| dst = (-src) & WMASK; | |
| if (dstreg) | |
| WrRegW (dst, dstspec); | |
| else WrMemW (dst, ea); | |
| CC_IIZZ_W (dst); | |
| if (dst == 0100000) | |
| cc = cc | CC_V; | |
| if (dst) | |
| cc = cc | CC_C; | |
| break; | |
| case 055: /* ADC */ | |
| if (dstreg) | |
| src = RdRegW (dstspec); | |
| else src = RdMemMW (ea = GeteaW (dstspec)); | |
| dst = (src + (cc & CC_C)) & WMASK; | |
| if (dstreg) | |
| WrRegW (dst, dstspec); | |
| else WrMemW (dst, ea); | |
| CC_IIZZ_W (dst); | |
| if ((src == 077777) && (dst == 0100000)) | |
| cc = cc | CC_V; | |
| if ((src == 0177777) && (dst == 0)) | |
| cc = cc | CC_C; | |
| break; | |
| case 056: /* SBC */ | |
| if (dstreg) | |
| src = RdRegW (dstspec); | |
| else src = RdMemMW (ea = GeteaW (dstspec)); | |
| dst = (src - (cc & CC_C)) & WMASK; | |
| if (dstreg) | |
| WrRegW (dst, dstspec); | |
| else WrMemW (dst, ea); | |
| CC_IIZZ_W (dst); | |
| if ((src == 0100000) && (dst == 077777)) | |
| cc = cc | CC_V; | |
| if ((src == 0) && (dst == 0177777)) | |
| cc = cc | CC_C; | |
| break; | |
| case 057: /* TST */ | |
| if (dstreg) | |
| src = RdRegW (dstspec); | |
| else src = RdMemW (GeteaW (dstspec)); | |
| CC_IIZZ_W (src); | |
| break; | |
| case 060: /* ROR */ | |
| if (dstreg) | |
| src = RdRegW (dstspec); | |
| else src = RdMemMW (ea = GeteaW (dstspec)); | |
| dst = (src >> 1) | ((cc & CC_C)? WSIGN: 0); | |
| if (dstreg) | |
| WrRegW (dst, dstspec); | |
| else WrMemW (dst, ea); | |
| CC_IIZZ_W (dst); | |
| if (src & 1) | |
| cc = cc | CC_C; | |
| if (CC_XOR_NC (cc)) | |
| cc = cc | CC_V; | |
| break; | |
| case 061: /* ROL */ | |
| if (dstreg) | |
| src = RdRegW (dstspec); | |
| else src = RdMemMW (ea = GeteaW (dstspec)); | |
| dst = ((src << 1) | ((cc & CC_C)? 1: 0)) & WMASK; | |
| if (dstreg) | |
| WrRegW (dst, dstspec); | |
| else WrMemW (dst, ea); | |
| CC_IIZZ_W (dst); | |
| if (src & WSIGN) | |
| cc = cc | CC_C; | |
| if (CC_XOR_NC (cc)) | |
| cc = cc | CC_V; | |
| break; | |
| case 062: /* ASR */ | |
| if (dstreg) | |
| src = RdRegW (dstspec); | |
| else src = RdMemMW (ea = GeteaW (dstspec)); | |
| dst = (src & WSIGN) | (src >> 1); | |
| if (dstreg) | |
| WrRegW (dst, dstspec); | |
| else WrMemW (dst, ea); | |
| CC_IIZZ_W (dst); | |
| if (src & 1) | |
| cc = cc | CC_C; | |
| if (CC_XOR_NC (cc)) | |
| cc = cc | CC_V; | |
| break; | |
| case 063: /* ASL */ | |
| if (dstreg) | |
| src = RdRegW (dstspec); | |
| else src = RdMemMW (ea = GeteaW (dstspec)); | |
| dst = (src << 1) & WMASK; | |
| if (dstreg) | |
| WrRegW (dst, dstspec); | |
| else WrMemW (dst, ea); | |
| CC_IIZZ_W (dst); | |
| if (src & WSIGN) | |
| cc = cc | CC_C; | |
| if (CC_XOR_NC (cc)) | |
| cc = cc | CC_V; | |
| break; | |
| case 065: /* MFPI */ | |
| if (dstreg) /* "mov dst,-(sp)" */ | |
| dst = RdRegW (dstspec); | |
| else dst = RdMemW (GeteaW (dstspec)); | |
| WrMemW (dst, (R[6] - 2) & WMASK); | |
| R[6] = (R[6] - 2) & WMASK; | |
| CC_IIZP_W (dst); | |
| break; | |
| case 066: /* MTPI */ | |
| dst = RdMemW (R[6] & WMASK); /* "mov (sp)+,dst" */ | |
| R[6] = (R[6] + 2) & WMASK; | |
| recq[recqptr++] = RQ_REC (AIN|RW, 6); | |
| if (dstreg) | |
| WrRegW (dst, dstspec); | |
| else WrMemW (dst, (GeteaW (dstspec) & WMASK)); | |
| CC_IIZP_W (dst); | |
| break; | |
| case 067: /* SXT */ | |
| dst = (cc & CC_N)? 0177777: 0; | |
| if (dstreg) | |
| WrRegW (dst, dstspec); | |
| else WrMemW (dst, GeteaW (dstspec)); | |
| CC_IIZP_W (dst); | |
| break; | |
| default: /* undefined */ | |
| CMODE_FAULT (CMODE_RSVI); | |
| break; | |
| } /* end switch SOPs */ | |
| break; /* end case 000 */ | |
| /* Opcodes 01 - 06: double operand word instructions | |
| Compatibility mode requires source address decode, source fetch, | |
| dest address decode, dest fetch/store. | |
| Add: v = [sign (src) = sign (src2)] and [sign (src) != sign (result)] | |
| Cmp: v = [sign (src) != sign (src2)] and [sign (src2) = sign (result)] | |
| */ | |
| case 001: /* MOV */ | |
| if (srcreg) | |
| src = RdRegW (srcspec); | |
| else src = RdMemW (GeteaW (srcspec)); | |
| if (dstreg) | |
| WrRegW (src, dstspec); | |
| else WrMemW (src, GeteaW (dstspec)); | |
| CC_IIZP_W (src); | |
| break; | |
| case 002: /* CMP */ | |
| if (srcreg) | |
| src = RdRegW (srcspec); | |
| else src = RdMemW (GeteaW (srcspec)); | |
| if (dstreg) | |
| src2 = RdRegW (dstspec); | |
| else src2 = RdMemW (GeteaW (dstspec)); | |
| dst = (src - src2) & WMASK; | |
| CC_IIZZ_W (dst); | |
| if (((src ^ src2) & (~src2 ^ dst)) & WSIGN) | |
| cc = cc | CC_V; | |
| if (src < src2) | |
| cc = cc | CC_C; | |
| break; | |
| case 003: /* BIT */ | |
| if (srcreg) | |
| src = RdRegW (srcspec); | |
| else src = RdMemW (GeteaW (srcspec)); | |
| if (dstreg) | |
| src2 = RdRegW (dstspec); | |
| else src2 = RdMemW (GeteaW (dstspec)); | |
| dst = src2 & src; | |
| CC_IIZP_W (dst); | |
| break; | |
| case 004: /* BIC */ | |
| if (srcreg) | |
| src = RdRegW (srcspec); | |
| else src = RdMemW (GeteaW (srcspec)); | |
| if (dstreg) | |
| src2 = RdRegW (dstspec); | |
| else src2 = RdMemMW (ea = GeteaW (dstspec)); | |
| dst = src2 & ~src; | |
| if (dstreg) | |
| WrRegW (dst, dstspec); | |
| else WrMemW (dst, ea); | |
| CC_IIZP_W (dst); | |
| break; | |
| case 005: /* BIS */ | |
| if (srcreg) | |
| src = RdRegW (srcspec); | |
| else src = RdMemW (GeteaW (srcspec)); | |
| if (dstreg) | |
| src2 = RdRegW (dstspec); | |
| else src2 = RdMemMW (ea = GeteaW (dstspec)); | |
| dst = src2 | src; | |
| if (dstreg) | |
| WrRegW (dst, dstspec); | |
| else WrMemW (dst, ea); | |
| CC_IIZP_W (dst); | |
| break; | |
| case 006: /* ADD */ | |
| if (srcreg) | |
| src = RdRegW (srcspec); | |
| else src = RdMemW (GeteaW (srcspec)); | |
| if (dstreg) | |
| src2 = RdRegW (dstspec); | |
| else src2 = RdMemMW (ea = GeteaW (dstspec)); | |
| dst = (src2 + src) & WMASK; | |
| if (dstreg) | |
| WrRegW (dst, dstspec); | |
| else WrMemW (dst, ea); | |
| CC_ADD_W (dst, src, src2); | |
| break; | |
| /* Opcode 07: EIS, FIS (not implemented), CIS | |
| Notes: | |
| - MUL carry: C is set if the (signed) result doesn't fit in 16 bits. | |
| - Divide has three error cases: | |
| 1. Divide by zero. | |
| 2. Divide largest negative number by -1. | |
| 3. (Signed) quotient doesn't fit in 16 bits. | |
| Cases 1 and 2 must be tested in advance, to avoid C runtime errors. | |
| - ASHx left: overflow if the bits shifted out do not equal the sign | |
| of the result (convert shift out to 1/0, xor against sign). | |
| - ASHx right: if right shift sign extends, then the shift and | |
| conditional or of shifted -1 is redundant. If right shift zero | |
| extends, then the shift and conditional or does sign extension. | |
| */ | |
| case 007: /* EIS */ | |
| srcspec = srcspec & 07; /* get src reg */ | |
| switch ((IR >> 9) & 07) { /* decode IR<11:9> */ | |
| case 0: /* MUL */ | |
| if (dstreg) /* get src2 */ | |
| src2 = RdRegW (dstspec); | |
| else src2 = RdMemW (GeteaW (dstspec)); | |
| src = RdRegW (srcspec); /* get src */ | |
| if (src2 & WSIGN) /* sext src, src2 */ | |
| src2 = src2 | ~WMASK; | |
| if (src & WSIGN) | |
| src = src | ~WMASK; | |
| dst = src * src2; /* multiply */ | |
| WrRegW ((dst >> 16) & WMASK, srcspec); /* high 16b */ | |
| WrRegW (dst & WMASK, srcspec | 1); /* low 16b */ | |
| CC_IIZZ_L (dst & LMASK); | |
| if ((dst > 077777) || (dst < -0100000)) | |
| cc = cc | CC_C; | |
| break; | |
| case 1: /* DIV */ | |
| if (dstreg) /* get src2 */ | |
| src2 = RdRegW (dstspec); | |
| else src2 = RdMemW (GeteaW (dstspec)); | |
| t = RdRegW (srcspec); | |
| src = (((uint32) t) << 16) | RdRegW (srcspec | 1); | |
| if (src2 == 0) { /* div by 0? */ | |
| cc = CC_V | CC_C; /* set cc's */ | |
| break; /* done */ | |
| } | |
| if ((src == LSIGN) && (src2 == WMASK)) { /* -2^31 / -1? */ | |
| cc = CC_V; /* overflow */ | |
| break; /* done */ | |
| } | |
| if (src2 & WSIGN) /* sext src, src2 */ | |
| src2 = src2 | ~WMASK; | |
| if (t & WSIGN) | |
| src = src | ~LMASK; | |
| dst = src / src2; /* divide */ | |
| if ((dst > 077777) || (dst < -0100000)) { /* out of range? */ | |
| cc = CC_V; /* overflow */ | |
| break; | |
| } | |
| CC_IIZZ_W (dst & WMASK); /* set cc's */ | |
| WrRegW (dst & WMASK, srcspec); /* quotient */ | |
| WrRegW ((src - (src2 * dst)) & WMASK, srcspec | 1); | |
| break; | |
| case 2: /* ASH */ | |
| if (dstreg) /* get src2 */ | |
| src2 = RdRegW (dstspec); | |
| else src2 = RdMemW (GeteaW (dstspec)); | |
| src2 = src2 & 077; | |
| src = RdRegW (srcspec); /* get src */ | |
| if (sign = ((src & WSIGN)? 1: 0)) | |
| src = src | ~WMASK; | |
| if (src2 == 0) { /* [0] */ | |
| dst = src; /* result */ | |
| oc = 0; /* last bit out */ | |
| } | |
| else if (src2 <= 15) { /* [1,15] */ | |
| dst = src << src2; | |
| i = (src >> (16 - src2)) & WMASK; | |
| oc = (i & 1)? CC_C: 0; | |
| if ((dst & WSIGN)? (i != WMASK): (i != 0)) | |
| oc = oc | CC_V; | |
| } | |
| else if (src2 <= 31) { /* [16,31] */ | |
| dst = 0; | |
| oc = ((src << (src2 - 16)) & 1)? CC_C: 0; | |
| if (src) | |
| oc = oc | CC_V; | |
| } | |
| else if (src2 == 32) { /* [32] = -32 */ | |
| dst = -sign; | |
| oc = sign? CC_C: 0; | |
| } | |
| else { /* [33,63] = -31,-1 */ | |
| dst = (src >> (64 - src2)) | (-sign << (src2 - 32)); | |
| oc = ((src >> (63 - src2)) & 1)? CC_C: 0; | |
| } | |
| WrRegW (dst = dst & WMASK, srcspec); /* result */ | |
| CC_IIZZ_W (dst); | |
| cc = cc | oc; | |
| break; | |
| case 3: /* ASHC */ | |
| if (dstreg) /* get src2 */ | |
| src2 = RdRegW (dstspec); | |
| else src2 = RdMemW (GeteaW (dstspec)); | |
| src2 = src2 & 077; | |
| t = RdRegW (srcspec); | |
| src = (((uint32) t) << 16) | RdRegW (srcspec | 1); | |
| sign = (t & WSIGN)? 1: 0; /* get src sign */ | |
| if (src2 == 0) { /* [0] */ | |
| dst = src; /* result */ | |
| oc = 0; /* last bit out */ | |
| } | |
| else if (src2 <= 31) { /* [1,31] */ | |
| dst = ((uint32) src) << src2; | |
| i = ((src >> (32 - src2)) | (-sign << src2)) & LMASK; | |
| oc = (i & 1)? CC_C: 0; | |
| if ((dst & LSIGN)? (i != LMASK): (i != 0)) | |
| oc = oc | CC_V; | |
| } | |
| else if (src2 == 32) { /* [32] = -32 */ | |
| dst = -sign; | |
| oc = sign? CC_C: 0; | |
| } | |
| else { /* [33,63] = -31,-1 */ | |
| dst = (src >> (64 - src2)) | (-sign << (src2 - 32)); | |
| oc = ((src >> (63 - src2)) & 1)? CC_C: 0; | |
| } | |
| WrRegW ((dst >> 16) & WMASK, srcspec); /* high result */ | |
| WrRegW (dst & WMASK, srcspec | 1); /* low result */ | |
| CC_IIZZ_L (dst & LMASK); | |
| cc = cc | oc; | |
| break; | |
| case 4: /* XOR */ | |
| src = RdRegW (srcspec); /* get src */ | |
| if (dstreg) /* get dst */ | |
| src2 = RdRegW (dstspec); | |
| else src2 = RdMemMW (ea = GeteaW (dstspec)); | |
| dst = src2 ^ src; | |
| if (dstreg) /* result */ | |
| WrRegW (dst, dstspec); | |
| else WrMemW (dst, ea); | |
| CC_IIZP_W (dst); | |
| break; | |
| case 7: /* SOB */ | |
| dst = (RdRegW (srcspec) - 1) & WMASK; /* decr reg */ | |
| WrRegW (dst, srcspec); /* result */ | |
| if (dst != 0) { /* br if zero */ | |
| CMODE_JUMP ((PC - dstspec - dstspec) & WMASK); | |
| } | |
| break; | |
| default: | |
| CMODE_FAULT (CMODE_RSVI); /* end switch EIS */ | |
| } | |
| break; /* end case 007 */ | |
| /* Opcode 10: branches, traps, SOPs */ | |
| case 010: | |
| switch ((IR >> 6) & 077) { /* decode IR<11:6> */ | |
| case 000: case 001: /* BPL */ | |
| if ((cc & CC_N) == 0) { | |
| BRANCH_F (IR); | |
| } | |
| break; | |
| case 002: case 003: /* BPL */ | |
| if ((cc & CC_N) == 0) { | |
| BRANCH_B (IR); | |
| } | |
| break; | |
| case 004: case 005: /* BMI */ | |
| if (cc & CC_N) { | |
| BRANCH_F (IR); | |
| } | |
| break; | |
| case 006: case 007: /* BMI */ | |
| if (cc & CC_N) { | |
| BRANCH_B (IR); | |
| } | |
| break; | |
| case 010: case 011: /* BHI */ | |
| if ((cc & (CC_C | CC_Z)) == 0) { | |
| BRANCH_F (IR); | |
| } | |
| break; | |
| case 012: case 013: /* BHI */ | |
| if ((cc & (CC_C | CC_Z)) == 0) { | |
| BRANCH_B (IR); | |
| } | |
| break; | |
| case 014: case 015: /* BLOS */ | |
| if (cc & (CC_C | CC_Z)) { | |
| BRANCH_F (IR); | |
| } | |
| break; | |
| case 016: case 017: /* BLOS */ | |
| if (cc & (CC_C | CC_Z)) { | |
| BRANCH_B (IR); | |
| } | |
| break; | |
| case 020: case 021: /* BVC */ | |
| if ((cc & CC_V) == 0) { | |
| BRANCH_F (IR); | |
| } | |
| break; | |
| case 022: case 023: /* BVC */ | |
| if ((cc & CC_V) == 0) { | |
| BRANCH_B (IR); | |
| } | |
| break; | |
| case 024: case 025: /* BVS */ | |
| if (cc & CC_V) { | |
| BRANCH_F (IR); | |
| } | |
| break; | |
| case 026: case 027: /* BVS */ | |
| if (cc & CC_V) { | |
| BRANCH_B (IR); | |
| } | |
| break; | |
| case 030: case 031: /* BCC */ | |
| if ((cc & CC_C) == 0) { | |
| BRANCH_F (IR); | |
| } | |
| break; | |
| case 032: case 033: /* BCC */ | |
| if ((cc & CC_C) == 0) { | |
| BRANCH_B (IR); | |
| } | |
| break; | |
| case 034: case 035: /* BCS */ | |
| if (cc & CC_C) { | |
| BRANCH_F (IR); | |
| } | |
| break; | |
| case 036: case 037: /* BCS */ | |
| if (cc & CC_C) { | |
| BRANCH_B (IR); | |
| } | |
| break; | |
| case 040: case 041: case 042: case 043: /* EMT */ | |
| CMODE_FAULT (CMODE_EMT); | |
| break; | |
| case 044: case 045: case 046: case 047: /* TRAP */ | |
| CMODE_FAULT (CMODE_TRAP); | |
| break; | |
| case 050: /* CLRB */ | |
| if (dstreg) | |
| WrRegB (0, dstspec); | |
| else WrMemB (0, GeteaB (dstspec)); | |
| cc = CC_Z; | |
| break; | |
| case 051: /* COMB */ | |
| if (dstreg) | |
| src = RdRegB (dstspec); | |
| else src = RdMemMB (ea = GeteaB (dstspec)); | |
| dst = src ^ BMASK; | |
| if (dstreg) | |
| WrRegB (dst, dstspec); | |
| else WrMemB (dst, ea); | |
| CC_IIZZ_B (dst); | |
| cc = cc | CC_C; | |
| break; | |
| case 052: /* INCB */ | |
| if (dstreg) | |
| src = RdRegB (dstspec); | |
| else src = RdMemMB (ea = GeteaB (dstspec)); | |
| dst = (src + 1) & BMASK; | |
| if (dstreg) | |
| WrRegB (dst, dstspec); | |
| else WrMemB (dst, ea); | |
| CC_IIZP_B (dst); | |
| if (dst == 0200) | |
| cc = cc | CC_V; | |
| break; | |
| case 053: /* DECB */ | |
| if (dstreg) | |
| src = RdRegB (dstspec); | |
| else src = RdMemMB (ea = GeteaB (dstspec)); | |
| dst = (src - 1) & BMASK; | |
| if (dstreg) | |
| WrRegB (dst, dstspec); | |
| else WrMemB (dst, ea); | |
| CC_IIZP_B (dst); | |
| if (dst == 0177) | |
| cc = cc | CC_V; | |
| break; | |
| case 054: /* NEGB */ | |
| if (dstreg) | |
| src = RdRegB (dstspec); | |
| else src = RdMemMB (ea = GeteaB (dstspec)); | |
| dst = (-src) & BMASK; | |
| if (dstreg) | |
| WrRegB (dst, dstspec); | |
| else WrMemB (dst, ea); | |
| CC_IIZZ_B (dst); | |
| if (dst == 0200) | |
| cc = cc | CC_V; | |
| if (dst) | |
| cc = cc | CC_C; | |
| break; | |
| case 055: /* ADCB */ | |
| if (dstreg) | |
| src = RdRegB (dstspec); | |
| else src = RdMemMB (ea = GeteaB (dstspec)); | |
| dst = (src + (cc & CC_C)) & BMASK; | |
| if (dstreg) | |
| WrRegB (dst, dstspec); | |
| else WrMemB (dst, ea); | |
| CC_IIZZ_B (dst); | |
| if ((src == 0177) && (dst == 0200)) | |
| cc = cc | CC_V; | |
| if ((src == 0377) && (dst == 0)) | |
| cc = cc | CC_C; | |
| break; | |
| case 056: /* SBCB */ | |
| if (dstreg) | |
| src = RdRegB (dstspec); | |
| else src = RdMemMB (ea = GeteaB (dstspec)); | |
| dst = (src - (cc & CC_C)) & BMASK; | |
| if (dstreg) | |
| WrRegB (dst, dstspec); | |
| else WrMemB (dst, ea); | |
| CC_IIZZ_B (dst); | |
| if ((src == 0200) && (dst == 0177)) | |
| cc = cc | CC_V; | |
| if ((src == 0) && (dst == 0377)) | |
| cc = cc | CC_C; | |
| break; | |
| case 057: /* TSTB */ | |
| if (dstreg) | |
| src = RdRegB (dstspec); | |
| else src = RdMemB (GeteaB (dstspec)); | |
| CC_IIZZ_B (src); | |
| break; | |
| case 060: /* RORB */ | |
| if (dstreg) | |
| src = RdRegB (dstspec); | |
| else src = RdMemMB (ea = GeteaB (dstspec)); | |
| dst = (src >> 1) | ((cc & CC_C)? BSIGN: 0); | |
| if (dstreg) | |
| WrRegB (dst, dstspec); | |
| else WrMemB (dst, ea); | |
| CC_IIZZ_B (dst); | |
| if (src & 1) | |
| cc = cc | CC_C; | |
| if (CC_XOR_NC (cc)) | |
| cc = cc | CC_V; | |
| break; | |
| case 061: /* ROLB */ | |
| if (dstreg) | |
| src = RdRegB (dstspec); | |
| else src = RdMemMB (ea = GeteaB (dstspec)); | |
| dst = ((src << 1) | ((cc & CC_C)? 1: 0)) & BMASK; | |
| if (dstreg) | |
| WrRegB (dst, dstspec); | |
| else WrMemB (dst, ea); | |
| CC_IIZZ_B (dst); | |
| if (src & BSIGN) | |
| cc = cc | CC_C; | |
| if (CC_XOR_NC (cc)) | |
| cc = cc | CC_V; | |
| break; | |
| case 062: /* ASRB */ | |
| if (dstreg) | |
| src = RdRegB (dstspec); | |
| else src = RdMemMB (ea = GeteaB (dstspec)); | |
| dst = (src >> 1) | (src & BSIGN); | |
| if (dstreg) | |
| WrRegB (dst, dstspec); | |
| else WrMemB (dst, ea); | |
| CC_IIZZ_B (dst); | |
| if (src & 1) | |
| cc = cc | CC_C; | |
| if (CC_XOR_NC (cc)) | |
| cc = cc | CC_V; | |
| break; | |
| case 063: /* ASLB */ | |
| if (dstreg) | |
| src = RdRegB (dstspec); | |
| else src = RdMemMB (ea = GeteaB (dstspec)); | |
| dst = (src << 1) & BMASK; | |
| if (dstreg) | |
| WrRegB (dst, dstspec); | |
| else WrMemB (dst, ea); | |
| CC_IIZZ_B (dst); | |
| if (src & BSIGN) | |
| cc = cc | CC_C; | |
| if (CC_XOR_NC (cc)) | |
| cc = cc | CC_V; | |
| break; | |
| case 065: /* MFPD */ | |
| if (dstreg) /* "mov dst,-(sp)" */ | |
| dst = RdRegW (dstspec); | |
| else dst = RdMemW (GeteaW (dstspec)); | |
| WrMemW (dst, (R[6] - 2) & WMASK); | |
| R[6] = (R[6] - 2) & WMASK; | |
| CC_IIZP_W (dst); | |
| break; | |
| case 066: /* MTPD */ | |
| dst = RdMemW (R[6] & WMASK); /* "mov (sp)+,dst" */ | |
| R[6] = (R[6] + 2) & WMASK; | |
| recq[recqptr++] = RQ_REC (AIN|RW, 6); | |
| if (dstreg) | |
| WrRegW (dst, dstspec); | |
| else WrMemW (dst, (GeteaW (dstspec) & WMASK)); | |
| CC_IIZP_W (dst); | |
| break; | |
| default: | |
| CMODE_FAULT (CMODE_RSVI); | |
| break; } /* end switch SOPs */ | |
| break; /* end case 010 */ | |
| /* Opcodes 11 - 16: double operand byte instructions | |
| Cmp: v = [sign (src) != sign (src2)] and [sign (src2) = sign (result)] | |
| Sub: v = [sign (src) != sign (src2)] and [sign (src) = sign (result)] | |
| */ | |
| case 011: /* MOVB */ | |
| if (srcreg) | |
| src = RdRegB (srcspec); | |
| else src = RdMemB (GeteaB (srcspec)); | |
| if (dstreg) | |
| WrRegW ((src & BSIGN)? (0xFF00 | src): src, dstspec); | |
| else WrMemB (src, GeteaB (dstspec)); | |
| CC_IIZP_B (src); | |
| break; | |
| case 012: /* CMPB */ | |
| if (srcreg) | |
| src = RdRegB (srcspec); | |
| else src = RdMemB (GeteaB (srcspec)); | |
| if (dstreg) | |
| src2 = RdRegB (dstspec); | |
| else src2 = RdMemB (GeteaB (dstspec)); | |
| dst = (src - src2) & BMASK; | |
| CC_IIZZ_B (dst); | |
| if (((src ^ src2) & (~src2 ^ dst)) & BSIGN) | |
| cc = cc | CC_V; | |
| if (src < src2) | |
| cc = cc | CC_C; | |
| break; | |
| case 013: /* BITB */ | |
| if (srcreg) | |
| src = RdRegB (srcspec); | |
| else src = RdMemB (GeteaB (srcspec)); | |
| if (dstreg) | |
| src2 = RdRegB (dstspec); | |
| else src2 = RdMemB (GeteaB (dstspec)); | |
| dst = src2 & src; | |
| CC_IIZP_B (dst); | |
| break; | |
| case 014: /* BICB */ | |
| if (srcreg) | |
| src = RdRegB (srcspec); | |
| else src = RdMemB (GeteaB (srcspec)); | |
| if (dstreg) | |
| src2 = RdRegB (dstspec); | |
| else src2 = RdMemMB (ea = GeteaB (dstspec)); | |
| dst = src2 & ~src; | |
| if (dstreg) | |
| WrRegB (dst, dstspec); | |
| else WrMemB (dst, ea); | |
| CC_IIZP_B (dst); | |
| break; | |
| case 015: /* BISB */ | |
| if (srcreg) | |
| src = RdRegB (srcspec); | |
| else src = RdMemB (GeteaB (srcspec)); | |
| if (dstreg) | |
| src2 = RdRegB (dstspec); | |
| else src2 = RdMemMB (ea = GeteaB (dstspec)); | |
| dst = src2 | src; | |
| if (dstreg) | |
| WrRegB (dst, dstspec); | |
| else WrMemB (dst, ea); | |
| CC_IIZP_B (dst); | |
| break; | |
| case 016: /* SUB */ | |
| if (srcreg) | |
| src = RdRegW (srcspec); | |
| else src = RdMemW (GeteaW (srcspec)); | |
| if (dstreg) | |
| src2 = RdRegW (dstspec); | |
| else src2 = RdMemMW (ea = GeteaW (dstspec)); | |
| dst = (src2 - src) & WMASK; | |
| if (dstreg) | |
| WrRegW (dst, dstspec); | |
| else WrMemW (dst, ea); | |
| CC_IIZZ_W (dst); | |
| if (((src ^ src2) & (~src ^ dst)) & WSIGN) | |
| cc = cc | CC_V; | |
| if (src2 < src) | |
| cc = cc | CC_C; | |
| break; | |
| default: | |
| CMODE_FAULT (CMODE_RSVI); | |
| break; | |
| } /* end switch op */ | |
| return cc; | |
| } | |
| /* Effective address calculations | |
| Inputs: | |
| spec = specifier <5:0> | |
| Outputs: | |
| ea = effective address | |
| */ | |
| int32 GeteaW (int32 spec) | |
| { | |
| int32 adr, reg; | |
| reg = spec & 07; /* register number */ | |
| switch (spec >> 3) { /* decode spec<5:3> */ | |
| default: /* can't get here */ | |
| case 1: /* (R) */ | |
| if (reg == 7) | |
| return (PC & WMASK); | |
| else return (R[reg] & WMASK); | |
| case 2: /* (R)+ */ | |
| if (reg == 7) | |
| PC = ((adr = PC) + 2) & WMASK; | |
| else { | |
| R[reg] = ((adr = R[reg]) + 2) & WMASK; | |
| recq[recqptr++] = RQ_REC (AIN|RW, reg); | |
| } | |
| return adr; | |
| case 3: /* @(R)+ */ | |
| if (reg == 7) | |
| PC = ((adr = PC) + 2) & WMASK; | |
| else { | |
| R[reg] = ((adr = R[reg]) + 2) & WMASK; | |
| recq[recqptr++] = RQ_REC (AIN|RW, reg); | |
| } | |
| return RdMemW (adr); | |
| case 4: /* -(R) */ | |
| if (reg == 7) | |
| adr = PC = (PC - 2) & WMASK; | |
| else { | |
| adr = R[reg] = (R[reg] - 2) & WMASK; | |
| recq[recqptr++] = RQ_REC (ADC|RW, reg); | |
| } | |
| return adr; | |
| case 5: /* @-(R) */ | |
| if (reg == 7) | |
| adr = PC = (PC - 2) & WMASK; | |
| else { | |
| adr = R[reg] = (R[reg] - 2) & WMASK; | |
| recq[recqptr++] = RQ_REC (ADC|RW, reg); | |
| } | |
| return RdMemW (adr); | |
| case 6: /* d(r) */ | |
| adr = RdMemW (PC); | |
| PC = (PC + 2) & WMASK; | |
| if (reg == 7) | |
| return ((PC + adr) & WMASK); | |
| else return ((R[reg] + adr) & WMASK); | |
| case 7: /* @d(R) */ | |
| adr = RdMemW (PC); | |
| PC = (PC + 2) & WMASK; | |
| if (reg == 7) | |
| adr = (PC + adr) & WMASK; | |
| else adr = (R[reg] + adr) & WMASK; | |
| return RdMemW (adr); | |
| } /* end switch */ | |
| } | |
| int32 GeteaB (int32 spec) | |
| { | |
| int32 adr, reg; | |
| reg = spec & 07; /* reg number */ | |
| switch (spec >> 3) { /* decode spec<5:3> */ | |
| default: /* can't get here */ | |
| case 1: /* (R) */ | |
| if (reg == 7) | |
| return (PC & WMASK); | |
| else return (R[reg] & WMASK); | |
| case 2: /* (R)+ */ | |
| if (reg == 7) | |
| PC = ((adr = PC) + 2) & WMASK; | |
| else if (reg == 6) { | |
| R[reg] = ((adr = R[reg]) + 2) & WMASK; | |
| recq[recqptr++] = RQ_REC (AIN|RW, reg); | |
| } | |
| else { | |
| R[reg] = ((adr = R[reg]) + 1) & WMASK; | |
| recq[recqptr++] = RQ_REC (AIN|RB, reg); | |
| } | |
| return adr; | |
| case 3: /* @(R)+ */ | |
| if (reg == 7) | |
| PC = ((adr = PC) + 2) & WMASK; | |
| else { | |
| R[reg] = ((adr = R[reg]) + 2) & WMASK; | |
| recq[recqptr++] = RQ_REC (AIN|RW, reg); | |
| } | |
| return RdMemW (adr); | |
| case 4: /* -(R) */ | |
| if (reg == 7) | |
| adr = PC = (PC - 2) & WMASK; | |
| else if (reg == 6) { | |
| adr = R[reg] = (R[reg] - 2) & WMASK; | |
| recq[recqptr++] = RQ_REC (ADC|RW, reg); | |
| } | |
| else { | |
| adr = R[reg] = (R[reg] - 1) & WMASK; | |
| recq[recqptr++] = RQ_REC (ADC|RB, reg); | |
| } | |
| return adr; | |
| case 5: /* @-(R) */ | |
| if (reg == 7) | |
| adr = PC = (PC - 2) & WMASK; | |
| else { | |
| adr = R[reg] = (R[reg] - 2) & WMASK; | |
| recq[recqptr++] = RQ_REC (ADC|RW, reg); | |
| } | |
| return RdMemW (adr); | |
| case 6: /* d(r) */ | |
| adr = RdMemW (PC); | |
| PC = (PC + 2) & WMASK; | |
| if (reg == 7) | |
| return ((PC + adr) & WMASK); | |
| else return ((R[reg] + adr) & WMASK); | |
| case 7: /* @d(R) */ | |
| adr = RdMemW (PC); | |
| PC = (PC + 2) & WMASK; | |
| if (reg == 7) | |
| adr = (PC + adr) & WMASK; | |
| else adr = (R[reg] + adr) & WMASK; | |
| return RdMemW (adr); | |
| } /* end switch */ | |
| } | |
| /* Memory and register access routines */ | |
| int32 RdMemW (int32 a) | |
| { | |
| int32 acc = ACC_MASK (USER); | |
| if (a & 1) | |
| CMODE_FAULT (CMODE_ODD); | |
| return Read (a, L_WORD, RA); | |
| } | |
| int32 RdMemMW (int32 a) | |
| { | |
| int32 acc = ACC_MASK (USER); | |
| if (a & 1) | |
| CMODE_FAULT (CMODE_ODD); | |
| return Read (a, L_WORD, WA); | |
| } | |
| void WrMemW (int32 d, int32 a) | |
| { | |
| int32 acc = ACC_MASK (USER); | |
| if (a & 1) | |
| CMODE_FAULT (CMODE_ODD); | |
| Write (a, d, L_WORD, WA); | |
| return; | |
| } | |
| int32 RdRegB (int32 rn) | |
| { | |
| if (rn == 7) | |
| return (PC & BMASK); | |
| else return (R[rn] & BMASK); | |
| } | |
| int32 RdRegW (int32 rn) | |
| { | |
| if (rn == 7) | |
| return (PC & WMASK); | |
| else return (R[rn] & WMASK); | |
| } | |
| void WrRegB (int32 val, int32 rn) | |
| { | |
| if (rn == 7) { | |
| CMODE_JUMP ((PC & ~BMASK) | val); | |
| } | |
| else R[rn] = (R[rn] & ~BMASK) | val; | |
| return; | |
| } | |
| void WrRegW (int32 val, int32 rn) | |
| { | |
| if (rn == 7) { | |
| CMODE_JUMP (val); | |
| } | |
| else R[rn] = val; | |
| return; | |
| } | |
| #else | |
| /* Subset VAX | |
| Never legal to set CM in PSL | |
| Should never get to instruction execution | |
| */ | |
| extern jmp_buf save_env; | |
| t_bool BadCmPSL (int32 newpsl) | |
| { | |
| return TRUE; /* always bad */ | |
| } | |
| int32 op_cmode (int32 cc) | |
| { | |
| RSVD_INST_FAULT; | |
| return cc; | |
| } | |
| #endif |