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+/* -----------------------------------------------------------------------------
+ *
+ * (c) The GHC Team, 1998-2004
+ *
+ * Registers in the STG machine.
+ *
+ * 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).
+ *
+ * ---------------------------------------------------------------------------*/
+
+#ifndef REGS_H
+#define REGS_H
+
+#include "gmp.h" // Needs MP_INT definition
+
+/*
+ * Spark pools: used to store pending sparks
+ * (THREADED_RTS & PARALLEL_HASKELL only)
+ * This is a circular buffer. Invariants:
+ * - base <= hd < lim
+ * - base <= tl < lim
+ * - if hd==tl, then the pool is empty.
+ * - if hd == tl+1, then the pool is full.
+ * Adding to the pool is done by assigning to *tl++ (wrapping round as
+ * necessary). When adding to a full pool, we have the option of
+ * throwing away either the oldest (hd++) or the most recent (tl--) entry.
+ */
+typedef struct StgSparkPool_ {
+ StgClosure **base;
+ StgClosure **lim;
+ StgClosure **hd;
+ StgClosure **tl;
+} StgSparkPool;
+
+#define ASSERT_SPARK_POOL_INVARIANTS(p) \
+ ASSERT((p)->base <= (p)->hd); \
+ ASSERT((p)->hd < (p)->lim); \
+ ASSERT((p)->base <= (p)->tl); \
+ ASSERT((p)->tl < (p)->lim);
+
+typedef struct {
+ 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;
+ StgInt8 i8;
+ StgFloat f;
+ StgInt i;
+ StgPtr p;
+ StgClosurePtr cl;
+ StgStackOffset offset; /* unused? */
+ StgByteArray b;
+ StgTSOPtr t;
+} 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 step_ *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 */
+ // rmp_tmp1..rmp_result2 are only used in THREADED_RTS builds to
+ // avoid per-thread temps in bss, but currently always incldue here
+ // so we just run mkDerivedConstants once
+ StgInt rmp_tmp_w;
+ MP_INT rmp_tmp1;
+ MP_INT rmp_tmp2;
+ MP_INT rmp_result1;
+ MP_INT rmp_result2;
+ StgWord rRet; // holds the return code of the thread
+#if defined(THREADED_RTS) || defined(PAR)
+ StgSparkPool rSparks; /* per-task spark pool */
+#endif
+} 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_HpLim (BaseReg->rHpLim)
+
+#define SAVE_CurrentTSO (BaseReg->rCurrentTSO)
+#define SAVE_CurrentNursery (BaseReg->rCurrentNursery)
+#define SAVE_HpAlloc (BaseReg->rHpAlloc)
+#define SAVE_SparkHd (BaseReg->rSparks.hd)
+#define SAVE_SparkTl (BaseReg->rSparks.tl)
+#define SAVE_SparkBase (BaseReg->rSparks.base)
+#define SAVE_SparkLim (BaseReg->rSparks.lim)
+
+/* 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)
+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
+#ifdef THREADED_RTS
+#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)
+GLOBAL_REG_DECL(P_,HpLim,REG_HpLim)
+#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
+
+#if defined(REG_SparkHd) && !defined(NO_GLOBAL_REG_DECLS)
+GLOBAL_REG_DECL(bdescr *,SparkHd,REG_SparkHd)
+#else
+#define SparkHd (BaseReg->rSparks.hd)
+#endif
+
+#if defined(REG_SparkTl) && !defined(NO_GLOBAL_REG_DECLS)
+GLOBAL_REG_DECL(bdescr *,SparkTl,REG_SparkTl)
+#else
+#define SparkTl (BaseReg->rSparks.tl)
+#endif
+
+#if defined(REG_SparkBase) && !defined(NO_GLOBAL_REG_DECLS)
+GLOBAL_REG_DECL(bdescr *,SparkBase,REG_SparkBase)
+#else
+#define SparkBase (BaseReg->rSparks.base)
+#endif
+
+#if defined(REG_SparkLim) && !defined(NO_GLOBAL_REG_DECLS)
+GLOBAL_REG_DECL(bdescr *,SparkLim,REG_SparkLim)
+#else
+#define SparkLim (BaseReg->rSparks.lim)
+#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 - sizeof(StgFunTable)))
+
+#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_HpLim
+#define CALLER_SAVE_HpLim SAVE_HpLim = HpLim;
+#define CALLER_RESTORE_HpLim HpLim = SAVE_HpLim;
+#else
+#define CALLER_SAVE_HpLim /* nothing */
+#define CALLER_RESTORE_HpLim /* 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
+
+#ifdef CALLER_SAVES_SparkHd
+#define CALLER_SAVE_SparkHd SAVE_SparkHd = SparkHd;
+#define CALLER_RESTORE_SparkHd SparkHd = SAVE_SparkHd;
+#else
+#define CALLER_SAVE_SparkHd /* nothing */
+#define CALLER_RESTORE_SparkHd /* nothing */
+#endif
+
+#ifdef CALLER_SAVES_SparkTl
+#define CALLER_SAVE_SparkTl SAVE_SparkTl = SparkTl;
+#define CALLER_RESTORE_SparkTl SparkTl = SAVE_SparkTl;
+#else
+#define CALLER_SAVE_SparkTl /* nothing */
+#define CALLER_RESTORE_SparkTl /* nothing */
+#endif
+
+#ifdef CALLER_SAVES_SparkBase
+#define CALLER_SAVE_SparkBase SAVE_SparkBase = SparkBase;
+#define CALLER_RESTORE_SparkBase SparkBase = SAVE_SparkBase;
+#else
+#define CALLER_SAVE_SparkBase /* nothing */
+#define CALLER_RESTORE_SparkBase /* nothing */
+#endif
+
+#ifdef CALLER_SAVES_SparkLim
+#define CALLER_SAVE_SparkLim SAVE_SparkLim = SparkLim;
+#define CALLER_RESTORE_SparkLim SparkLim = SAVE_SparkLim;
+#else
+#define CALLER_SAVE_SparkLim /* nothing */
+#define CALLER_RESTORE_SparkLim /* 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_HpLim \
+ CALLER_SAVE_CurrentTSO \
+ CALLER_SAVE_CurrentNursery \
+ CALLER_SAVE_SparkHd \
+ CALLER_SAVE_SparkTl \
+ CALLER_SAVE_SparkBase \
+ CALLER_SAVE_SparkLim \
+ 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_HpLim \
+ CALLER_RESTORE_CurrentTSO \
+ CALLER_RESTORE_CurrentNursery \
+ CALLER_RESTORE_SparkHd \
+ CALLER_RESTORE_SparkTl \
+ CALLER_RESTORE_SparkBase \
+ CALLER_RESTORE_SparkLim
+
+#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 */