diff options
| -rw-r--r-- | sys/src/9/pc/main.c | 62 |
1 files changed, 59 insertions, 3 deletions
diff --git a/sys/src/9/pc/main.c b/sys/src/9/pc/main.c index 538bec15b..ae78ed153 100644 --- a/sys/src/9/pc/main.c +++ b/sys/src/9/pc/main.c @@ -480,11 +480,23 @@ confinit(void) void fpx87save(FPsave *fps) { + ushort tag; + fpx87save0(fps); + /* + * convert x87 tag word to fxsave tag byte: + * 00, 01, 10 -> 1, 11 -> 0 + */ + tag = ~fps->tag; + tag = (tag | (tag >> 1)) & 0x5555; + tag = (tag | (tag >> 1)) & 0x3333; + tag = (tag | (tag >> 2)) & 0x0F0F; + tag = (tag | (tag >> 4)) & 0x00FF; + /* NOP fps->fcw = fps->control; */ fps->fsw = fps->status; - fps->ftw = fps->tag; + fps->ftw = tag; fps->fop = fps->opcode; fps->fpuip = fps->pc; fps->cs = fps->selector; @@ -528,6 +540,36 @@ fpx87save(FPsave *fps) void fpx87restore(FPsave *fps) { + ushort msk, tos, tag, *reg; + + /* convert fxsave tag byte to x87 tag word */ + tag = 0; + tos = 7 - ((fps->fsw >> 11) & 7); + for(msk = 0x80; msk != 0; tos--, msk >>= 1){ + tag <<= 2; + if((fps->ftw & msk) != 0){ + reg = (ushort*)&fps->xregs[(tos & 7) << 4]; + switch(reg[4] & 0x7fff){ + case 0x0000: + if((reg[0] | reg[1] | reg[2] | reg[3]) == 0){ + tag |= 1; /* 01 zero */ + break; + } + /* no break */ + case 0x7fff: + tag |= 2; /* 10 special */ + break; + default: + if((reg[3] & 0x8000) == 0) + break; /* 00 valid */ + tag |= 2; /* 10 special */ + break; + } + }else{ + tag |= 3; /* 11 empty */ + } + } + #define MOVA(d,s) \ *((ulong*)(d)) = *((ulong*)(s)), \ *((ulong*)(d+4)) = *((ulong*)(s+4)), \ @@ -546,10 +588,10 @@ fpx87restore(FPsave *fps) fps->oselector = fps->ds; fps->operand = fps->fpudp; - fps->opcode = (fps->fop & 0x7ff); + fps->opcode = fps->fop & 0x7ff; fps->selector = fps->cs; fps->pc = fps->fpuip; - fps->tag = fps->ftw; + fps->tag = tag; fps->status = fps->fsw; /* NOP fps->control = fps->fcw; */ @@ -726,6 +768,8 @@ procsetup(Proc *p) void procfork(Proc *p) { + int s; + p->kentry = up->kentry; p->pcycles = -p->kentry; @@ -738,6 +782,18 @@ procfork(Proc *p) memmove(p->ldt, up->ldt, sizeof(Segdesc) * up->nldt); p->nldt = up->nldt; } + + /* save floating point state */ + s = splhi(); + switch(up->fpstate & ~FPillegal){ + case FPactive: + fpsave(&up->fpsave); + up->fpstate = FPinactive; + case FPinactive: + p->fpsave = up->fpsave; + p->fpstate = FPinactive; + } + splx(s); } void |