/* ----------------------------------------------------------------------------- * * (c) The GHC Team, 1998-2009 * * Registers in the STG machine. * * Do not #include this file directly: #include "Rts.h" instead. * * To understand the structure of the RTS headers, see the wiki: * http://hackage.haskell.org/trac/ghc/wiki/Commentary/SourceTree/Includes * * ---------------------------------------------------------------------------*/ #ifndef REGS_H #define REGS_H /* * The STG machine has a collection of "registers", each one of which * may or may not correspond to an actual machine register when * running code. * * The register set is backed by a table in memory (struct * StgRegTable). If a particular STG register is not mapped to a * machine register, then the apprpriate slot in this table is used * instead. * * This table is itself pointed to by another register, BaseReg. If * BaseReg is not in a machine register, then the register table is * used from an absolute location (MainCapability). * */ typedef struct { StgWord stgEagerBlackholeInfo; StgFunPtr stgGCEnter1; StgFunPtr stgGCFun; } StgFunTable; /* * Vanilla registers are given this union type, which is purely so * that we can cast the vanilla reg to a variety of types with the * minimum of syntax. eg. R1.w instead of (StgWord)R1. */ typedef union { StgWord w; StgAddr a; StgChar c; StgFloat f; StgInt i; StgPtr p; } StgUnion; /* * This is the table that holds shadow-locations for all the STG * registers. The shadow locations are used when: * * 1) the particular register isn't mapped to a real machine * register, probably because there's a shortage of real registers. * 2) caller-saves registers are saved across a CCall */ typedef struct StgRegTable_ { StgUnion rR1; StgUnion rR2; StgUnion rR3; StgUnion rR4; StgUnion rR5; StgUnion rR6; StgUnion rR7; StgUnion rR8; StgUnion rR9; /* used occasionally by heap/stack checks */ StgUnion rR10; /* used occasionally by heap/stack checks */ StgFloat rF1; StgFloat rF2; StgFloat rF3; StgFloat rF4; StgDouble rD1; StgDouble rD2; StgWord64 rL1; StgPtr rSp; StgPtr rSpLim; StgPtr rHp; StgPtr rHpLim; struct StgTSO_ * rCurrentTSO; struct nursery_ * rNursery; struct bdescr_ * rCurrentNursery; /* Hp/HpLim point into this block */ struct bdescr_ * rCurrentAlloc; /* for allocation using allocate() */ StgWord rHpAlloc; /* number of *bytes* being allocated in heap */ StgWord rRet; // holds the return code of the thread } StgRegTable; #if IN_STG_CODE /* * Registers Hp and HpLim are global across the entire system, and are * copied into the RegTable before executing a thread. * * Registers Sp and SpLim are saved in the TSO for the * thread, but are copied into the RegTable before executing a thread. * * All other registers are "general purpose", and are used for passing * arguments to functions, and returning values. The code generator * knows how many of these are in real registers, and avoids * generating code that uses non-real registers. General purpose * registers are never saved when returning to the scheduler, instead * we save whatever is live at the time on the stack, and restore it * later. This should reduce the context switch time, amongst other * things. * * For argument passing, the stack will be used in preference to * pseudo-registers if the architecture has too few general purpose * registers. * * Some special RTS functions like newArray and the Integer primitives * expect their arguments to be in registers R1-Rn, so we use these * (pseudo-)registers in those cases. */ /* * Locations for saving per-thread registers. */ #define SAVE_Sp (CurrentTSO->sp) #define SAVE_SpLim (CurrentTSO->splim) #define SAVE_Hp (BaseReg->rHp) #define SAVE_CurrentTSO (BaseReg->rCurrentTSO) #define SAVE_CurrentNursery (BaseReg->rCurrentNursery) #define SAVE_HpAlloc (BaseReg->rHpAlloc) /* We sometimes need to save registers across a C-call, eg. if they * are clobbered in the standard calling convention. We define the * save locations for all registers in the register table. */ #define SAVE_R1 (BaseReg->rR1) #define SAVE_R2 (BaseReg->rR2) #define SAVE_R3 (BaseReg->rR3) #define SAVE_R4 (BaseReg->rR4) #define SAVE_R5 (BaseReg->rR5) #define SAVE_R6 (BaseReg->rR6) #define SAVE_R7 (BaseReg->rR7) #define SAVE_R8 (BaseReg->rR8) #define SAVE_F1 (BaseReg->rF1) #define SAVE_F2 (BaseReg->rF2) #define SAVE_F3 (BaseReg->rF3) #define SAVE_F4 (BaseReg->rF4) #define SAVE_D1 (BaseReg->rD1) #define SAVE_D2 (BaseReg->rD2) #define SAVE_L1 (BaseReg->rL1) /* ----------------------------------------------------------------------------- * Emit the GCC-specific register declarations for each machine * register being used. If any STG register isn't mapped to a machine * register, then map it to an offset from BaseReg. * * First, the general purpose registers. The idea is, if a particular * general-purpose STG register can't be mapped to a real machine * register, it won't be used at all. Instead, we'll use the stack. * * This is an improvement on the way things used to be done, when all * registers were mapped to locations in the register table, and stuff * was being shifted from the stack to the register table and back * again for no good reason (on register-poor architectures). */ /* define NO_REGS to omit register declarations - used in RTS C code * that needs all the STG definitions but not the global register * settings. */ #define GLOBAL_REG_DECL(type,name,reg) register type name REG(reg); #if defined(REG_R1) && !defined(NO_GLOBAL_REG_DECLS) GLOBAL_REG_DECL(StgUnion,R1,REG_R1) #else # define R1 (BaseReg->rR1) #endif #if defined(REG_R2) && !defined(NO_GLOBAL_REG_DECLS) GLOBAL_REG_DECL(StgUnion,R2,REG_R2) #else # define R2 (BaseReg->rR2) #endif #if defined(REG_R3) && !defined(NO_GLOBAL_REG_DECLS) GLOBAL_REG_DECL(StgUnion,R3,REG_R3) #else # define R3 (BaseReg->rR3) #endif #if defined(REG_R4) && !defined(NO_GLOBAL_REG_DECLS) GLOBAL_REG_DECL(StgUnion,R4,REG_R4) #else # define R4 (BaseReg->rR4) #endif #if defined(REG_R5) && !defined(NO_GLOBAL_REG_DECLS) GLOBAL_REG_DECL(StgUnion,R5,REG_R5) #else # define R5 (BaseReg->rR5) #endif #if defined(REG_R6) && !defined(NO_GLOBAL_REG_DECLS) GLOBAL_REG_DECL(StgUnion,R6,REG_R6) #else # define R6 (BaseReg->rR6) #endif #if defined(REG_R7) && !defined(NO_GLOBAL_REG_DECLS) GLOBAL_REG_DECL(StgUnion,R7,REG_R7) #else # define R7 (BaseReg->rR7) #endif #if defined(REG_R8) && !defined(NO_GLOBAL_REG_DECLS) GLOBAL_REG_DECL(StgUnion,R8,REG_R8) #else # define R8 (BaseReg->rR8) #endif #if defined(REG_R9) && !defined(NO_GLOBAL_REG_DECLS) GLOBAL_REG_DECL(StgUnion,R9,REG_R9) #else # define R9 (BaseReg->rR9) #endif #if defined(REG_R10) && !defined(NO_GLOBAL_REG_DECLS) GLOBAL_REG_DECL(StgUnion,R10,REG_R10) #else # define R10 (BaseReg->rR10) #endif #if defined(REG_F1) && !defined(NO_GLOBAL_REG_DECLS) GLOBAL_REG_DECL(StgFloat,F1,REG_F1) #else #define F1 (BaseReg->rF1) #endif #if defined(REG_F2) && !defined(NO_GLOBAL_REG_DECLS) GLOBAL_REG_DECL(StgFloat,F2,REG_F2) #else #define F2 (BaseReg->rF2) #endif #if defined(REG_F3) && !defined(NO_GLOBAL_REG_DECLS) GLOBAL_REG_DECL(StgFloat,F3,REG_F3) #else #define F3 (BaseReg->rF3) #endif #if defined(REG_F4) && !defined(NO_GLOBAL_REG_DECLS) GLOBAL_REG_DECL(StgFloat,F4,REG_F4) #else #define F4 (BaseReg->rF4) #endif #if defined(REG_D1) && !defined(NO_GLOBAL_REG_DECLS) GLOBAL_REG_DECL(StgDouble,D1,REG_D1) #else #define D1 (BaseReg->rD1) #endif #if defined(REG_D2) && !defined(NO_GLOBAL_REG_DECLS) GLOBAL_REG_DECL(StgDouble,D2,REG_D2) #else #define D2 (BaseReg->rD2) #endif #if defined(REG_L1) && !defined(NO_GLOBAL_REG_DECLS) GLOBAL_REG_DECL(StgWord64,L1,REG_L1) #else #define L1 (BaseReg->rL1) #endif /* * If BaseReg isn't mapped to a machine register, just use the global * address of the current register table (CurrentRegTable in * concurrent Haskell, MainRegTable otherwise). */ /* A capability is a combination of a FunTable and a RegTable. In STG * code, BaseReg normally points to the RegTable portion of this * structure, so that we can index both forwards and backwards to take * advantage of shorter instruction forms on some archs (eg. x86). * This is a cut-down version of the Capability structure; the full * version is defined in Capability.h. */ struct PartCapability_ { StgFunTable f; StgRegTable r; }; /* No such thing as a MainCapability under THREADED_RTS - each thread must have * its own Capability. */ #if IN_STG_CODE && !(defined(THREADED_RTS) && !defined(NOSMP)) extern W_ MainCapability[]; #endif /* * Assigning to BaseReg (the ASSIGN_BaseReg macro): this happens on * return from a "safe" foreign call, when the thread might be running * on a new Capability. Obviously if BaseReg is not a register, then * we are restricted to a single Capability (this invariant is enforced * in Capability.c:initCapabilities), and assigning to BaseReg can be omitted. */ #if defined(REG_Base) && !defined(NO_GLOBAL_REG_DECLS) GLOBAL_REG_DECL(StgRegTable *,BaseReg,REG_Base) #define ASSIGN_BaseReg(e) (BaseReg = (e)) #else #if defined(THREADED_RTS) && !defined(NOSMP) #error BaseReg must be in a register for THREADED_RTS #endif #define BaseReg (&((struct PartCapability_ *)MainCapability)->r) #define ASSIGN_BaseReg(e) (e) #endif #if defined(REG_Sp) && !defined(NO_GLOBAL_REG_DECLS) GLOBAL_REG_DECL(P_,Sp,REG_Sp) #else #define Sp (BaseReg->rSp) #endif #if defined(REG_SpLim) && !defined(NO_GLOBAL_REG_DECLS) GLOBAL_REG_DECL(P_,SpLim,REG_SpLim) #else #define SpLim (BaseReg->rSpLim) #endif #if defined(REG_Hp) && !defined(NO_GLOBAL_REG_DECLS) GLOBAL_REG_DECL(P_,Hp,REG_Hp) #else #define Hp (BaseReg->rHp) #endif #if defined(REG_HpLim) && !defined(NO_GLOBAL_REG_DECLS) #error HpLim cannot be in a register #else #define HpLim (BaseReg->rHpLim) #endif #if defined(REG_CurrentTSO) && !defined(NO_GLOBAL_REG_DECLS) GLOBAL_REG_DECL(struct _StgTSO *,CurrentTSO,REG_CurrentTSO) #else #define CurrentTSO (BaseReg->rCurrentTSO) #endif #if defined(REG_CurrentNursery) && !defined(NO_GLOBAL_REG_DECLS) GLOBAL_REG_DECL(bdescr *,CurrentNursery,REG_CurrentNursery) #else #define CurrentNursery (BaseReg->rCurrentNursery) #endif #if defined(REG_HpAlloc) && !defined(NO_GLOBAL_REG_DECLS) GLOBAL_REG_DECL(bdescr *,HpAlloc,REG_HpAlloc) #else #define HpAlloc (BaseReg->rHpAlloc) #endif /* ----------------------------------------------------------------------------- Get absolute function pointers from the register table, to save code space. On x86, jmp *-12(%ebx) is shorter than jmp absolute_address as long as the offset is within the range of a signed byte (-128..+127). So we pick some common absolute_addresses and put them in the register table. As a bonus, linking time should also be reduced. Other possible candidates in order of importance: stg_upd_frame_info stg_CAF_BLACKHOLE_info stg_IND_STATIC_info anything else probably isn't worth the effort. -------------------------------------------------------------------------- */ #define FunReg ((StgFunTable *)((void *)BaseReg - STG_FIELD_OFFSET(struct PartCapability_, r))) #define stg_EAGER_BLACKHOLE_info (FunReg->stgEagerBlackholeInfo) #define stg_gc_enter_1 (FunReg->stgGCEnter1) #define stg_gc_fun (FunReg->stgGCFun) /* ----------------------------------------------------------------------------- For any registers which are denoted "caller-saves" by the C calling convention, we have to emit code to save and restore them across C calls. -------------------------------------------------------------------------- */ #ifdef CALLER_SAVES_R1 #define CALLER_SAVE_R1 SAVE_R1 = R1; #define CALLER_RESTORE_R1 R1 = SAVE_R1; #else #define CALLER_SAVE_R1 /* nothing */ #define CALLER_RESTORE_R1 /* nothing */ #endif #ifdef CALLER_SAVES_R2 #define CALLER_SAVE_R2 SAVE_R2 = R2; #define CALLER_RESTORE_R2 R2 = SAVE_R2; #else #define CALLER_SAVE_R2 /* nothing */ #define CALLER_RESTORE_R2 /* nothing */ #endif #ifdef CALLER_SAVES_R3 #define CALLER_SAVE_R3 SAVE_R3 = R3; #define CALLER_RESTORE_R3 R3 = SAVE_R3; #else #define CALLER_SAVE_R3 /* nothing */ #define CALLER_RESTORE_R3 /* nothing */ #endif #ifdef CALLER_SAVES_R4 #define CALLER_SAVE_R4 SAVE_R4 = R4; #define CALLER_RESTORE_R4 R4 = SAVE_R4; #else #define CALLER_SAVE_R4 /* nothing */ #define CALLER_RESTORE_R4 /* nothing */ #endif #ifdef CALLER_SAVES_R5 #define CALLER_SAVE_R5 SAVE_R5 = R5; #define CALLER_RESTORE_R5 R5 = SAVE_R5; #else #define CALLER_SAVE_R5 /* nothing */ #define CALLER_RESTORE_R5 /* nothing */ #endif #ifdef CALLER_SAVES_R6 #define CALLER_SAVE_R6 SAVE_R6 = R6; #define CALLER_RESTORE_R6 R6 = SAVE_R6; #else #define CALLER_SAVE_R6 /* nothing */ #define CALLER_RESTORE_R6 /* nothing */ #endif #ifdef CALLER_SAVES_R7 #define CALLER_SAVE_R7 SAVE_R7 = R7; #define CALLER_RESTORE_R7 R7 = SAVE_R7; #else #define CALLER_SAVE_R7 /* nothing */ #define CALLER_RESTORE_R7 /* nothing */ #endif #ifdef CALLER_SAVES_R8 #define CALLER_SAVE_R8 SAVE_R8 = R8; #define CALLER_RESTORE_R8 R8 = SAVE_R8; #else #define CALLER_SAVE_R8 /* nothing */ #define CALLER_RESTORE_R8 /* nothing */ #endif #ifdef CALLER_SAVES_R9 #define CALLER_SAVE_R9 SAVE_R9 = R9; #define CALLER_RESTORE_R9 R9 = SAVE_R9; #else #define CALLER_SAVE_R9 /* nothing */ #define CALLER_RESTORE_R9 /* nothing */ #endif #ifdef CALLER_SAVES_R10 #define CALLER_SAVE_R10 SAVE_R10 = R10; #define CALLER_RESTORE_R10 R10 = SAVE_R10; #else #define CALLER_SAVE_R10 /* nothing */ #define CALLER_RESTORE_R10 /* nothing */ #endif #ifdef CALLER_SAVES_F1 #define CALLER_SAVE_F1 SAVE_F1 = F1; #define CALLER_RESTORE_F1 F1 = SAVE_F1; #else #define CALLER_SAVE_F1 /* nothing */ #define CALLER_RESTORE_F1 /* nothing */ #endif #ifdef CALLER_SAVES_F2 #define CALLER_SAVE_F2 SAVE_F2 = F2; #define CALLER_RESTORE_F2 F2 = SAVE_F2; #else #define CALLER_SAVE_F2 /* nothing */ #define CALLER_RESTORE_F2 /* nothing */ #endif #ifdef CALLER_SAVES_F3 #define CALLER_SAVE_F3 SAVE_F3 = F3; #define CALLER_RESTORE_F3 F3 = SAVE_F3; #else #define CALLER_SAVE_F3 /* nothing */ #define CALLER_RESTORE_F3 /* nothing */ #endif #ifdef CALLER_SAVES_F4 #define CALLER_SAVE_F4 SAVE_F4 = F4; #define CALLER_RESTORE_F4 F4 = SAVE_F4; #else #define CALLER_SAVE_F4 /* nothing */ #define CALLER_RESTORE_F4 /* nothing */ #endif #ifdef CALLER_SAVES_D1 #define CALLER_SAVE_D1 SAVE_D1 = D1; #define CALLER_RESTORE_D1 D1 = SAVE_D1; #else #define CALLER_SAVE_D1 /* nothing */ #define CALLER_RESTORE_D1 /* nothing */ #endif #ifdef CALLER_SAVES_D2 #define CALLER_SAVE_D2 SAVE_D2 = D2; #define CALLER_RESTORE_D2 D2 = SAVE_D2; #else #define CALLER_SAVE_D2 /* nothing */ #define CALLER_RESTORE_D2 /* nothing */ #endif #ifdef CALLER_SAVES_L1 #define CALLER_SAVE_L1 SAVE_L1 = L1; #define CALLER_RESTORE_L1 L1 = SAVE_L1; #else #define CALLER_SAVE_L1 /* nothing */ #define CALLER_RESTORE_L1 /* nothing */ #endif #ifdef CALLER_SAVES_Sp #define CALLER_SAVE_Sp SAVE_Sp = Sp; #define CALLER_RESTORE_Sp Sp = SAVE_Sp; #else #define CALLER_SAVE_Sp /* nothing */ #define CALLER_RESTORE_Sp /* nothing */ #endif #ifdef CALLER_SAVES_SpLim #define CALLER_SAVE_SpLim SAVE_SpLim = SpLim; #define CALLER_RESTORE_SpLim SpLim = SAVE_SpLim; #else #define CALLER_SAVE_SpLim /* nothing */ #define CALLER_RESTORE_SpLim /* nothing */ #endif #ifdef CALLER_SAVES_Hp #define CALLER_SAVE_Hp SAVE_Hp = Hp; #define CALLER_RESTORE_Hp Hp = SAVE_Hp; #else #define CALLER_SAVE_Hp /* nothing */ #define CALLER_RESTORE_Hp /* nothing */ #endif #ifdef CALLER_SAVES_Base #ifdef THREADED_RTS #error "Can't have caller-saved BaseReg with THREADED_RTS" #endif #define CALLER_SAVE_Base /* nothing */ #define CALLER_RESTORE_Base BaseReg = &MainRegTable; #else #define CALLER_SAVE_Base /* nothing */ #define CALLER_RESTORE_Base /* nothing */ #endif #ifdef CALLER_SAVES_CurrentTSO #define CALLER_SAVE_CurrentTSO SAVE_CurrentTSO = CurrentTSO; #define CALLER_RESTORE_CurrentTSO CurrentTSO = SAVE_CurrentTSO; #else #define CALLER_SAVE_CurrentTSO /* nothing */ #define CALLER_RESTORE_CurrentTSO /* nothing */ #endif #ifdef CALLER_SAVES_CurrentNursery #define CALLER_SAVE_CurrentNursery SAVE_CurrentNursery = CurrentNursery; #define CALLER_RESTORE_CurrentNursery CurrentNursery = SAVE_CurrentNursery; #else #define CALLER_SAVE_CurrentNursery /* nothing */ #define CALLER_RESTORE_CurrentNursery /* nothing */ #endif #ifdef CALLER_SAVES_HpAlloc #define CALLER_SAVE_HpAlloc SAVE_HpAlloc = HpAlloc; #define CALLER_RESTORE_HpAlloc HpAlloc = SAVE_HpAlloc; #else #define CALLER_SAVE_HpAlloc /* nothing */ #define CALLER_RESTORE_HpAlloc /* nothing */ #endif #endif /* IN_STG_CODE */ /* ---------------------------------------------------------------------------- Handy bunches of saves/restores ------------------------------------------------------------------------ */ #if IN_STG_CODE #define CALLER_SAVE_USER \ CALLER_SAVE_R1 \ CALLER_SAVE_R2 \ CALLER_SAVE_R3 \ CALLER_SAVE_R4 \ CALLER_SAVE_R5 \ CALLER_SAVE_R6 \ CALLER_SAVE_R7 \ CALLER_SAVE_R8 \ CALLER_SAVE_F1 \ CALLER_SAVE_F2 \ CALLER_SAVE_F3 \ CALLER_SAVE_F4 \ CALLER_SAVE_D1 \ CALLER_SAVE_D2 \ CALLER_SAVE_L1 /* Save Base last, since the others may be addressed relative to it */ #define CALLER_SAVE_SYSTEM \ CALLER_SAVE_Sp \ CALLER_SAVE_SpLim \ CALLER_SAVE_Hp \ CALLER_SAVE_CurrentTSO \ CALLER_SAVE_CurrentNursery \ CALLER_SAVE_Base #define CALLER_RESTORE_USER \ CALLER_RESTORE_R1 \ CALLER_RESTORE_R2 \ CALLER_RESTORE_R3 \ CALLER_RESTORE_R4 \ CALLER_RESTORE_R5 \ CALLER_RESTORE_R6 \ CALLER_RESTORE_R7 \ CALLER_RESTORE_R8 \ CALLER_RESTORE_F1 \ CALLER_RESTORE_F2 \ CALLER_RESTORE_F3 \ CALLER_RESTORE_F4 \ CALLER_RESTORE_D1 \ CALLER_RESTORE_D2 \ CALLER_RESTORE_L1 /* Restore Base first, since the others may be addressed relative to it */ #define CALLER_RESTORE_SYSTEM \ CALLER_RESTORE_Base \ CALLER_RESTORE_Sp \ CALLER_RESTORE_SpLim \ CALLER_RESTORE_Hp \ CALLER_RESTORE_CurrentTSO \ CALLER_RESTORE_CurrentNursery #else /* not IN_STG_CODE */ #define CALLER_SAVE_USER /* nothing */ #define CALLER_SAVE_SYSTEM /* nothing */ #define CALLER_RESTORE_USER /* nothing */ #define CALLER_RESTORE_SYSTEM /* nothing */ #endif /* IN_STG_CODE */ #define CALLER_SAVE_ALL \ CALLER_SAVE_SYSTEM \ CALLER_SAVE_USER #define CALLER_RESTORE_ALL \ CALLER_RESTORE_SYSTEM \ CALLER_RESTORE_USER #endif /* REGS_H */