mikepaul-LuaJIT/src/vm_s390x.dasc

|// Low-level VM code for IBM z/Architecture (s390x) CPUs in LJ_GC64 mode.
|// Bytecode interpreter, fast functions and helper functions.
|// Copyright (C) 2005-2016 Mike Pall. See Copyright Notice in luajit.h
|
|// ELF ABI registers:
|// r0,r1       |                            | volatile |
|// r2          | parameter and return value | volatile |
|// r3-r5       | parameter                  | volatile |
|// r6          | parameter                  | saved    |
|// r7-r11      |                            | saved    |
|// r12         | GOT pointer  (needed?)     | saved    |
|// r13         | literal pool (needed?)     | saved    |
|// r14         | return address             | volatile |
|// r15         | stack pointer              | saved    |
|// f0,f2,f4,f6 | parameter and return value | volatile |
|// f1,f3,f5,f7 |                            | volatile |
|// f8-f15      |                            | saved    |
|// ar0,ar1     | TLS                        | volatile |
|// ar2-ar15    |                            | volatile |
|
|// Instructions used that are not in base z/Architecture:
|//   clfi (compare logical immediate) [requires z9-109]
|// TODO: alternative instructions?
|
|.arch s390x
|.section code_op, code_sub
|
|.actionlist build_actionlist
|.globals GLOB_
|.globalnames globnames
|.externnames extnames
|
|//-----------------------------------------------------------------------
|
|// Fixed register assignments for the interpreter, callee-saved.
|.define BASE,			r7	// Base of current Lua stack frame.
|.define KBASE,			r8	// Constants of current Lua function.
|.define PC,			r9	// Next PC.
|.define DISPATCH,		r10	// Opcode dispatch table.
|.define LREG,			r11	// Register holding lua_State (also in SAVE_L).
|.define ITYPE,			r13	//
|
|// The following temporaries are not saved across C calls, except for RD.
|.define RA,			r1
|.define RB,			r12
|.define RC,			r5	// Overlaps CARG4.
|.define RD,			r6	// Overlaps CARG5. Callee-saved.
|
|// Calling conventions. Also used as temporaries.
|.define CARG1,			r2
|.define CARG2,			r3
|.define CARG3,			r4
|.define CARG4,			r5
|.define CARG5,			r6
|
|.define FARG1,			f0
|.define FARG2,			f2
|.define FARG3,			f4
|.define FARG4,			f6
|
|.define CRET1,			r2
|
|.define OP,			r2
|.define TMPR1,			r14
|.define TMPR2,			r0
|
|// Stack layout while in interpreter. Must match with lj_frame.h.
|.define CFRAME_SPACE,	240	// Delta for sp, 8 byte aligned.
|
|// Register save area.
|.define SAVE_GPRS,	288(sp)	// Save area for r6-r15 (10*8 bytes).
|.define SAVE_GPRS_P,	48(sp)  // Save area for r6-r15 (10*8 bytes) in prologue (before stack frame is allocated).
|
|// Argument save area.
|.define SAVE_ERRF,	280(sp) // Argument 4, in r5.
|.define SAVE_NRES,	272(sp)	// Argument 3, in r4. Size is 4-bytes.
|.define SAVE_CFRAME,	264(sp)	// Argument 2, in r3.
|.define SAVE_L,	256(sp)	// Argument 1, in r2.
|.define RESERVED,	248(sp)	// Reserved for compiler use.
|.define BACKCHAIN,	240(sp)	// <- sp entering interpreter.
|
|// Interpreter stack frame.
|.define SAVE_FPR15,	232(sp)
|.define SAVE_FPR14,	224(sp)
|.define SAVE_FPR13,	216(sp)
|.define SAVE_FPR12,	208(sp)
|.define SAVE_FPR11,	200(sp)
|.define SAVE_FPR10,	192(sp)
|.define SAVE_FPR9,	184(sp)
|.define SAVE_FPR8,	176(sp)
|.define SAVE_PC,	168(sp)
|.define SAVE_MULTRES,	160(sp)
|.define TMP_STACK,	160(sp) // Overlaps SAVE_MULTRES
|
|// Callee save area (allocated by interpreter).
|.define CALLEESAVE,	000(sp) // <- sp in interpreter.
|
|.macro saveregs
|  stmg r6, r15, SAVE_GPRS_P
|  lay sp, -CFRAME_SPACE(sp)	// Allocate stack frame.
|  // TODO: save backchain?
|  std f8, SAVE_FPR8		// f8-f15 are callee-saved.
|  std f9, SAVE_FPR9
|  std f10, SAVE_FPR10
|  std f11, SAVE_FPR11
|  std f12, SAVE_FPR12
|  std f13, SAVE_FPR13
|  std f14, SAVE_FPR14
|  std f15, SAVE_FPR15
|.endmacro
|
|.macro restoreregs
|  ld f8, SAVE_FPR8		// f8-f15 are callee-saved.
|  ld f9, SAVE_FPR9
|  ld f10, SAVE_FPR10
|  ld f11, SAVE_FPR11
|  ld f12, SAVE_FPR12
|  ld f13, SAVE_FPR13
|  ld f14, SAVE_FPR14
|  ld f15, SAVE_FPR15
|  lmg r6, r15, SAVE_GPRS	// Restores the stack pointer.
|.endmacro
|
|// Type definitions. Some of these are only used for documentation.
|.type L,		lua_State
|.type GL,		global_State
|.type TVALUE,		TValue
|.type GCOBJ,		GCobj
|.type STR,		GCstr
|.type TAB,		GCtab
|.type LFUNC,		GCfuncL
|.type CFUNC,		GCfuncC
|.type PROTO,		GCproto
|.type UPVAL,		GCupval
|.type NODE,		Node
|.type NARGS,		int
|.type TRACE,		GCtrace
|.type SBUF,		SBuf
|
|//-----------------------------------------------------------------------
|
|// Instruction headers.
|.macro ins_A; .endmacro
|.macro ins_AD; .endmacro
|.macro ins_AJ; .endmacro
|.macro ins_ABC; .endmacro
|.macro ins_AB_; .endmacro
|.macro ins_A_C; .endmacro
|.macro ins_AND; lghi TMPR1, -1; xgr RD, TMPR1; .endmacro // RD = ~RD
|
|// Instruction decode+dispatch.
|  // TODO: tune this, right now we always decode RA-D even if they aren't used.
|.macro ins_NEXT
|  llgf RD, 0(PC)
|  // 32                 63
|  // [  B |  C |  A | OP ]
|  // [    D    |  A | OP ]
|  llghr RA, RD
|  srlg RA, RA, 8(r0)
|  llgcr OP, RD
|  srlg RD, RD, 16(r0)
|  lgr RB, RD
|  srlg RB, RB, 8(r0)
|  llgcr RC, RD
|  la PC, 4(PC)
|  llgfr TMPR1, OP
|  sllg TMPR1, TMPR1, 3(r0) // TMPR1=OP*8
|  lg TMPR1, 0(TMPR1, DISPATCH)
|  br TMPR1
|.endmacro
|
|// Instruction footer.
|.if 1
|  // Replicated dispatch. Less unpredictable branches, but higher I-Cache use.
|  .define ins_next, ins_NEXT
|  .define ins_next_, ins_NEXT
|.else
|  // Common dispatch. Lower I-Cache use, only one (very) unpredictable branch.
|  .macro ins_next
|    jmp ->ins_next
|  .endmacro
|  .macro ins_next_
|  ->ins_next:
|    ins_NEXT
|  .endmacro
|.endif
|
|// Call decode and dispatch.
|.macro ins_callt
|  // BASE = new base, RB = LFUNC, RD = nargs+1, -8(BASE) = PC
|  lg PC, LFUNC:RB->pc
|  llgf RA, 0(PC) // TODO: combine loads?
|  llgcr OP, RA
|    sllg TMPR1, OP, 3(r0)
|  la PC, 4(PC)
|    lg TMPR1, 0(TMPR1, DISPATCH)
|    br TMPR1
|.endmacro
|
|.macro ins_call
|  // BASE = new base, RB = LFUNC, RD = nargs+1
|  stg PC, -8(BASE)
|  ins_callt
|.endmacro
|
|// Assumes DISPATCH is relative to GL.
#define DISPATCH_GL(field)	(GG_DISP2G + (int)offsetof(global_State, field))
#define DISPATCH_J(field)	(GG_DISP2J + (int)offsetof(jit_State, field))
|
#define PC2PROTO(field)  ((int)offsetof(GCproto, field)-(int)sizeof(GCproto))
|
|//-----------------------------------------------------------------------
|
|// Macros to clear or set tags.
|.macro cleartp, reg; sllg reg, reg, 17(r0); srlg reg, reg, 17(r0); .endmacro // TODO: use nihf instead? would introduce dependence on z9-109.
|.macro settp, reg, tp
|  oihh reg, ((tp>>1) &0xffff)
|  oihl reg, ((tp<<15)&0x8000)
|.endmacro
|.macro settp, dst, reg, tp
|  llihh dst, ((tp>>1) &0xffff)
|  iihl dst,  ((tp<<15)&0x8000)
|  ogr dst, reg
|.endmacro
|.macro setint, reg
|  settp reg, LJ_TISNUM
|.endmacro
|
|// Macros to test operand types.
|.macro checktp_nc, reg, tp, target
|  srag ITYPE, reg, 47(r0)
|  clfi ITYPE, tp
|  jne target
|.endmacro
|.macro checktp, reg, tp, target
|  srag ITYPE, reg, 47(r0)
|  cleartp reg
|  clfi ITYPE, tp
|  jne target
|.endmacro
|.macro checktptp, src, tp, target
|  srag ITYPE, src, 47(r0)
|  clfi ITYPE, tp
|  jne target
|.endmacro
|.macro checkstr, reg, target; checktp reg, LJ_TSTR, target; .endmacro
|.macro checktab, reg, target; checktp reg, LJ_TTAB, target; .endmacro
|.macro checkfunc, reg, target; checktp reg, LJ_TFUNC, target; .endmacro
|
|.macro checknumx, reg, target, jump
|  srag ITYPE, reg, 47(r0)
|  clfi ITYPE, LJ_TISNUM
|  jump target
|.endmacro
|.macro checkint, reg, target; checknumx reg, target, jne; .endmacro
|.macro checkinttp, src, target; checknumx src, target, jne; .endmacro
|.macro checknum, reg, target; checknumx reg, target, jhe; .endmacro
|.macro checknumtp, src, target; checknumx src, target, jhe; .endmacro
|.macro checknumber, src, target; checknumx src, target, jh; .endmacro
|
|.macro load_false, reg; lghi reg, -1; iihl reg, 0x7fff; .endmacro	// assumes LJ_TFALSE == ~(1<<47)
|.macro load_true, reg; lghi reg, -1; iihh reg, 0xfffe; .endmacro	// assumes LJ_TTRUE  == ~(2<<47)
|
|.define PC_OP, -1(PC)
|.define PC_RA, -2(PC)
|.define PC_RB, -4(PC)
|.define PC_RC, -3(PC)
|.define PC_RD, -4(PC)
|
|.macro branchPC, reg
|  // TODO: optimize this, was just lea PC, [PC+reg*4-BCBIAS_J*4].
|  // Can't clobber TMPR1 or condition code.
|  lgr TMPR2, TMPR1 // Workaround because TMPR2 == r0 and can't be used in lay.
|  sllg TMPR1, reg, 2(r0)
|  lay PC, (-BCBIAS_J*4)(TMPR1, PC)
|  lgr TMPR1, TMPR2
|.endmacro
|
|// Set current VM state.
|.macro set_vmstate, st
|  lghi TMPR1, ~LJ_VMST_..st
|  stg TMPR1, DISPATCH_GL(vmstate)(DISPATCH)
|.endmacro
|
|// Move table write barrier back. Overwrites reg.
|.macro barrierback, tab, reg
|  // TODO: more efficient way?
|  llgc reg, tab->marked
|  nill reg, (uint16_t)~LJ_GC_BLACK // black2gray(tab)
|  stc reg, tab->marked
|  lg reg, (DISPATCH_GL(gc.grayagain))(DISPATCH)
|  stg tab, (DISPATCH_GL(gc.grayagain))(DISPATCH)
|  stg reg, tab->gclist
|.endmacro

#if !LJ_DUALNUM
#error "Only dual-number mode supported for s390x target"
#endif

/* Generate subroutines used by opcodes and other parts of the VM. */
/* The .code_sub section should be last to help static branch prediction. */
static void build_subroutines(BuildCtx *ctx)
{
  |.code_sub
  |
  |//-----------------------------------------------------------------------
  |//-- Return handling ----------------------------------------------------
  |//-----------------------------------------------------------------------
  |
  |->vm_returnp:
  |  cghi PC, 0
  |  je ->cont_dispatch
  |
  |  // Return from pcall or xpcall fast func.
  |  nill PC, -7
  |  sgr BASE, PC			// Restore caller base.
  |  lay RA, -8(RA, PC)			// Rebase RA and prepend one result.
  |  lg PC, -8(BASE)			// Fetch PC of previous frame.
  |  // Prepending may overwrite the pcall frame, so do it at the end.
  |  load_true ITYPE
  |  stg ITYPE, 0(RA, BASE)		// Prepend true to results.
  |
  |->vm_returnc:
  |  aghi RD, 1				// RD = nresults+1
  |  jo ->vm_unwind_yield		// TODO: !!! NOT SURE, jz on x64, overflow? !!!
  |  stg RD, SAVE_MULTRES
  |  tmll PC, FRAME_TYPE
  |  je ->BC_RET_Z			// Handle regular return to Lua.
  |
  |->vm_return:
  |  // BASE = base, RA = resultofs, RD = nresults+1 (= MULTRES), PC = return
  |  lghi TMPR1, FRAME_C
  |  xgr PC, TMPR1
  |  tmll PC, FRAME_TYPE
  |  jne ->vm_returnp
  |
  |  // Return to C.
  |  set_vmstate C
  |  nill PC, -8
  |  sgr PC, BASE
  |  lcgr PC, PC			// Previous base = BASE - delta.
  |
  |  aghi RD, -1
  |  je >2
  |1:  // Move results down.
  |  lg RB, 0(BASE, RA)
  |  stg RB, -16(BASE)
  |  la BASE, 8(BASE)
  |  aghi RD, -1
  |  jne <1
  |2:
  |  lg L:RB, SAVE_L
  |  stg PC, L:RB->base
  |3:
  |  lg RD, SAVE_MULTRES
  |  lgf RA, SAVE_NRES			// RA = wanted nresults+1
  |4:
  |  cgr RA, RD
  |  jne >6				// More/less results wanted?
  |5:
  |  lay BASE, -16(BASE)
  |  stg BASE, L:RB->top
  |
  |->vm_leave_cp:
  |  lg RA, SAVE_CFRAME			// Restore previous C frame.
  |  stg RA, L:LREG->cframe
  |  lghi CRET1, 0			// Ok return status for vm_pcall.
  |
  |->vm_leave_unw:
  |  restoreregs
  |  br r14
  |
  |6:
  |  jl >7				// Less results wanted?
  |  // More results wanted. Check stack size and fill up results with nil.
  |  cg BASE, L:RB->maxstack
  |  jh >8
  |  lghi TMPR1, LJ_TNIL
  |  stg TMPR1, -16(BASE)
  |  la BASE, 8(BASE)
  |  aghi RD, 1
  |  j <4
  |
  |7:  // Fewer results wanted.
  |  cghi RA, 0
  |  je <5				// But check for LUA_MULTRET+1.
  |  sgr RA, RD				// Negative result!
  |  sllg TMPR1, RA, 3(r0)
  |  lay BASE, 0(TMPR1, BASE)		// Correct top.
  |  j <5
  |
  |8:  // Corner case: need to grow stack for filling up results.
  |  // This can happen if:
  |  // - A C function grows the stack (a lot).
  |  // - The GC shrinks the stack in between.
  |  // - A return back from a lua_call() with (high) nresults adjustment.
  |  stg BASE, L:RB->top		// Save current top held in BASE (yes).
  |  stg RD, SAVE_MULTRES		// Need to fill only remainder with nil.
  |  lgr CARG2, RA
  |  lgr CARG1, L:RB
  |  brasl r14, extern lj_state_growstack	// (lua_State *L, int n)
  |  lg BASE, L:RB->top			// Need the (realloced) L->top in BASE.
  |  j <3
  |
  |->vm_unwind_yield:
  |  lghi CRET1, LUA_YIELD
  |  j ->vm_unwind_c_eh
  |
  |->vm_unwind_c:			// Unwind C stack, return from vm_pcall.
  |  // (void *cframe, int errcode)
  |  lgr sp, CARG1
  |  lgfr CARG2, CRET1			// Error return status for vm_pcall.
  |->vm_unwind_c_eh:			// Landing pad for external unwinder.
  |  lg L:RB, SAVE_L
  |  lg GL:RB, L:RB->glref
  |  lghi TMPR1, ~LJ_VMST_C
  |  stg TMPR1, GL:RB->vmstate
  |  j ->vm_leave_unw
  |
  |->vm_unwind_rethrow:
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
  |
  |->vm_unwind_ff:			// Unwind C stack, return from ff pcall.
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
  |
  |->vm_unwind_ff_eh:			// Landing pad for external unwinder.
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
  |
  |//-----------------------------------------------------------------------
  |//-- Grow stack for calls -----------------------------------------------
  |//-----------------------------------------------------------------------
  |
  |->vm_growstack_c:			// Grow stack for C function.
  |  lghi CARG2, LUA_MINSTACK
  |  j >2
  |
  |->vm_growstack_v:			// Grow stack for vararg Lua function.
  |  aghi RD, -16			// LJ_FR2
  |  j >1
  |
  |->vm_growstack_f:			// Grow stack for fixarg Lua function.
  |  // BASE = new base, RD = nargs+1, RB = L, PC = first PC
  |  sllg RD, NARGS:RD, 3(r0)
  |  lay RD, -8(RD, BASE)
  |1:
  |  llgc RA, (PC2PROTO(framesize)-4)(PC)
  |  la PC, 4(PC)			// Must point after first instruction.
  |  stg BASE, L:RB->base
  |  stg RD, L:RB->top
  |  stg PC, SAVE_PC
  |  lgr CARG2, RA
  |2:
  |  // RB = L, L->base = new base, L->top = top
  |  lgr CARG1, L:RB
  |  brasl r14, extern lj_state_growstack	// (lua_State *L, int n)
  |  lg BASE, L:RB->base
  |  lg RD, L:RB->top
  |  lg LFUNC:RB, -16(BASE)
  |  cleartp LFUNC:RB
  |  sgr RD, BASE
  |  srlg RD, RD, 3(r0)
  |  aghi NARGS:RD, 1
  |  // BASE = new base, RB = LFUNC, RD = nargs+1
  |  ins_callt				// Just retry the call.
  |
  |//-----------------------------------------------------------------------
  |//-- Entry points into the assembler VM ---------------------------------
  |//-----------------------------------------------------------------------
  |
  |->vm_resume:				// Setup C frame and resume thread.
  |  // (lua_State *L, TValue *base, int nres1 = 0, ptrdiff_t ef = 0)
  |  saveregs
  |  lgr L:RB, CARG1			// Caveat: CARG1 may be RA.
  |  stg CARG1, SAVE_L
  |  lgr RA, CARG2
  |  lghi PC, FRAME_CP
  |  lghi RD, 0
  |  lay KBASE, CFRAME_RESUME(sp)
  |  lg DISPATCH, L:RB->glref		// Setup pointer to dispatch table.
  |  aghi DISPATCH, GG_G2DISP
  |  stg RD, SAVE_PC			// Any value outside of bytecode is ok.
  |  stg RD, SAVE_CFRAME
  |  st RD, SAVE_NRES
  |  stg RD, SAVE_ERRF
  |  stg KBASE, L:RB->cframe
  |  clm RD, 1, L:RB->status
  |  je >2				// Initial resume (like a call).
  |
  |  // Resume after yield (like a return).
  |  stg L:RB, (DISPATCH_GL(cur_L))(DISPATCH)
  |  set_vmstate INTERP
  |  llgc RD, L:RB->status
  |  lg BASE, L:RB->base
  |  lg RD, L:RB->top
  |  sgr RD, RA
  |  srlg RD, RD, 3(r0)
  |  aghi RD, 1				// RD = nresults+1
  |  sgr RA, BASE			// RA = resultofs
  |  lg PC, -8(BASE)
  |  stg RD, SAVE_MULTRES
  |  tmll PC, FRAME_TYPE
  |  je ->BC_RET_Z
  |  j ->vm_return
  |
  |->vm_pcall:				// Setup protected C frame and enter VM.
  |  // (lua_State *L, TValue *base, int nres1, ptrdiff_t ef)
  |  saveregs
  |  lghi PC, FRAME_CP
  |  llgfr CARG4, CARG4
  |  stg CARG4, SAVE_ERRF
  |  j >1
  |
  |->vm_call:				// Setup C frame and enter VM.
  |  // (lua_State *L, TValue *base, int nres1)
  |  saveregs
  |  lghi PC, FRAME_C
  |
  |1:  // Entry point for vm_pcall above (PC = ftype).
  |  st CARG3, SAVE_NRES
  |  lgr L:RB, CARG1
  |  stg CARG1, SAVE_L
  |  lgr RA, CARG2
  |
  |  lg DISPATCH, L:RB->glref		// Setup pointer to dispatch table.
  |  lg KBASE, L:RB->cframe		// Add our C frame to cframe chain.
  |  stg KBASE, SAVE_CFRAME
  |  stg L:RB, SAVE_PC			// Any value outside of bytecode is ok.
  |  aghi DISPATCH, GG_G2DISP
  |  stg sp, L:RB->cframe
  |  lgr L:LREG, L:RB			// TODO: use RB instead of LREG here?
  |
  |2: // Entry point for vm_resume/vm_cpcall (RA = base, LREG = L, PC = ftype).
  |  stg L:LREG, DISPATCH_GL(cur_L)(DISPATCH)
  |  set_vmstate INTERP
  |  lg BASE, L:LREG->base		// BASE = old base (used in vmeta_call).
  |  agr PC, RA
  |  sgr PC, BASE			// PC = frame delta + frame type
  |
  |  lg RD, L:LREG->top
  |  sgr RD, RA
  |  srlg NARGS:RD, NARGS:RD, 3(r0)	// TODO: support '3' on its own in dynasm.
  |  aghi NARGS:RD, 1			// RD = nargs+1
  |
  |->vm_call_dispatch:
  |  lg LFUNC:RB, -16(RA)
  |  checkfunc LFUNC:RB, ->vmeta_call	// Ensure KBASE defined and != BASE.
  |
  |->vm_call_dispatch_f:
  |  lgr BASE, RA
  |  ins_call
  |  // BASE = new base, RB = func, RD = nargs+1, PC = caller PC
  |
  |->vm_cpcall:				// Setup protected C frame, call C.
  |  // (lua_State *L, lua_CFunction func, void *ud, lua_CPFunction cp)
  |  saveregs
  |  lgr LREG, CARG1
  |  stg LREG, SAVE_L
  |  stg LREG, SAVE_PC			// Any value outside of bytecode is ok.
  |
  |  lg KBASE, L:LREG->stack		// Compute -savestack(L, L->top).
  |  sg KBASE, L:LREG->top
  |   lg DISPATCH, L:LREG->glref	// Setup pointer to dispatch table.
  |  lghi RA, 0
  |  stg RA, SAVE_ERRF			// No error function.
  |  st KBASE, SAVE_NRES		// Neg. delta means cframe w/o frame.
  |   aghi DISPATCH, GG_G2DISP
  |  // Handler may change cframe_nres(L->cframe) or cframe_errfunc(L->cframe).
  |
  |  lg KBASE, L:LREG->cframe		// Add our C frame to cframe chain.
  |  stg KBASE, SAVE_CFRAME
  |  stg sp, L:LREG->cframe
  |  stg L:LREG, DISPATCH_GL(cur_L)(DISPATCH)
  |
  |  basr r14, CARG4			// (lua_State *L, lua_CFunction func, void *ud)
  |  // TValue * (new base) or NULL returned in r2 (CRET1/).
  |  cghi CRET1, 0
  |  je ->vm_leave_cp			// No base? Just remove C frame.
  |  lgr RA, CRET1
  |  lghi PC, FRAME_CP
  |  j <2				// Else continue with the call.
  |
  |//-----------------------------------------------------------------------
  |//-- Metamethod handling ------------------------------------------------
  |//-----------------------------------------------------------------------
  |
  |//-- Continuation dispatch ----------------------------------------------
  |
  |->cont_dispatch:
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
  |
  |->cont_cat:				// BASE = base, RC = result, RB = mbase
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
  |
  |//-- Table indexing metamethods -----------------------------------------
  |
  |->vmeta_tgets:
  |  settp STR:RC, LJ_TSTR			// STR:RC = GCstr *
  |  stg STR:RC, TMP_STACK
  |  la RC, TMP_STACK
  |  llgc TMPR1, PC_OP
  |  cghi TMPR1, BC_GGET
  |  jne >1
  |  settp TAB:RA, TAB:RB, LJ_TTAB		// TAB:RB = GCtab *
  |  lay RB, (DISPATCH_GL(tmptv))(DISPATCH)	// Store fn->l.env in g->tmptv.
  |  stg TAB:RA, 0(RB)
  |  j >2
  |
  |->vmeta_tgetb:
  |  llgc RC, PC_RC
  |  setint RC
  |  stg RC, TMP_STACK
  |  la RC, TMP_STACK
  |  j >1
  |
  |->vmeta_tgetv:
  |  llgc RC, PC_RC			// Reload TValue *k from RC.
  |  sllg RC, RC, 3(r0)
  |  la RC, 0(RC, BASE)
  |1:
  |  llgc RB, PC_RB			// Reload TValue *t from RB.
  |  sllg RB, RB, 3(r0)
  |  la RB, 0(RB, BASE)
  |2:
  |  lg L:CARG1, SAVE_L
  |  stg BASE, L:CARG1->base
  |  lgr CARG2, RB
  |  lgr CARG3, RC
  |  lgr L:RB, L:CARG1
  |  stg PC, SAVE_PC
  |  brasl r14, extern lj_meta_tget	// (lua_State *L, TValue *o, TValue *k)
  |  // TValue * (finished) or NULL (metamethod) returned in r2 (CRET1).
  |  lg BASE, L:RB->base
  |  ltgr RC, CRET1
  |  je >3
  |->cont_ra:				// BASE = base, RC = result
  |  llgc RA, PC_RA
  |  sllg RA, RA, 3(r0)
  |  lg RB, 0(RC)
  |  stg RB, 0(RA, BASE)
  |  ins_next
  |
  |3:  // Call __index metamethod.
  |  // BASE = base, L->top = new base, stack = cont/func/t/k
  |  lg RA, L:RB->top
  |  stg PC, -24(PC)			// [cont|PC]
  |  lay PC, FRAME_CONT(RA)
  |  sgr PC, BASE
  |  lg LFUNC:RB, -16(RA)		// Guaranteed to be a function here.
  |  lghi NARGS:RD, 2+1			// 2 args for func(t, k).
  |  cleartp LFUNC:RB
  |  j ->vm_call_dispatch_f
  |
  |->vmeta_tgetr:
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
  |
  |//-----------------------------------------------------------------------
  |
  |->vmeta_tsets:
  |  settp STR:RC, LJ_TSTR			// STR:RC = GCstr *
  |  stg STR:RC, TMP_STACK
  |  la RC, TMP_STACK
  |  llgc TMPR2, PC_OP
  |  cghi TMPR2, BC_GSET
  |  jne >1
  |  settp TAB:RA, TAB:RB, LJ_TTAB		// TAB:RB = GCtab *
  |  lay RB, (DISPATCH_GL(tmptv))(DISPATCH)	// Store fn->l.env in g->tmptv.
  |  stg TAB:RA, 0(RB)
  |  j >2
  |
  |->vmeta_tsetb:
  |  llgc RC, PC_RC
  |  setint RC
  |  stg RC, TMP_STACK
  |  la RC, TMP_STACK
  |  j >1
  |
  |->vmeta_tsetv:
  |  llgc RC, PC_RC			// Reload TValue *k from RC.
  |  sllg RC, RC, 3(r0)
  |  la RC, 0(RC, BASE)
  |1:
  |  llgc RB, PC_RB			// Reload TValue *t from RB.
  |  sllg RB, RB, 3(r0)
  |  la RB, 0(RB, BASE)
  |2:
  |  lg L:CARG1, SAVE_L
  |  stg BASE, L:CARG1->base		// Caveat: CARG2/CARG3 may be BASE.
  |  lgr CARG2, RB
  |  lgr CARG3, RC
  |  lgr L:RB, L:CARG1
  |  stg PC, SAVE_PC
  |  brasl r14, extern lj_meta_tset	// (lua_State *L, TValue *o, TValue *k)
  |  // TValue * (finished) or NULL (metamethod) returned in r2 (CRET1).
  |  lg BASE, L:RB->base
  |  ltgr RC, CRET1
  |  je >3
  |  // NOBARRIER: lj_meta_tset ensures the table is not black.
  |  llgc RA, PC_RA
  |  sllg RA, RA, 3(r0)
  |  lg RB, 0(RA, BASE)
  |  stg RB, 0(RC)
  |->cont_nop:				// BASE = base, (RC = result)
  |  ins_next
  |
  |3:  // Call __newindex metamethod.
  |  // BASE = base, L->top = new base, stack = cont/func/t/k/(v)
  |  lg RA, L:RB->top
  |  stg PC, -24(PC)			// [cont|PC]
  |  llgc RC, PC_RA
  |  // Copy value to third argument.
  |  sllg RB, RC, 3(r0)
  |  lg RB, 0(RB, BASE)
  |  stg RB, 16(RA)
  |  la PC, FRAME_CONT(RA)
  |  sgr PC, BASE
  |  lg LFUNC:RB, -16(RA)		// Guaranteed to be a function here.
  |  lghi NARGS:RD, 3+1			// 3 args for func(t, k, v).
  |  cleartp LFUNC:RB
  |  j ->vm_call_dispatch_f
  |
  |->vmeta_tsetr:
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
  |
  |//-- Comparison metamethods ---------------------------------------------
  |
  |->vmeta_comp:
  |  llgh RD, PC_RD
  |  sllg RD, RD, 3(r0)
  |  llgc RA, PC_RA
  |  sllg RA, RA, 3(r0)
  |  lg L:RB, SAVE_L
  |  stg BASE, L:RB->base
  |  la CARG2, 0(RA, BASE)
  |  la CARG3, 0(RD, BASE)
  |  lgr CARG1, L:RB
  |  llgc CARG4, PC_OP
  |  stg PC, SAVE_PC
  |  brasl r14, extern lj_meta_comp	// (lua_State *L, TValue *o1, *o2, int op)
  |  // 0/1 or TValue * (metamethod) returned in r2 (CRET1).
  |3:
  |  lg BASE, L:RB->base
  |  clgfi CRET1, 1
  |  jh ->vmeta_binop
  |4:
  |  la PC, 4(PC)
  |  jl >6
  |5:
  |  llgh RD, PC_RD
  |  branchPC RD
  |6:
  |  ins_next
  |
  |->cont_condt:			// BASE = base, RC = result
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
  |
  |->cont_condf:			// BASE = base, RC = result
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
  |
  |->vmeta_equal:
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
  |
  |->vmeta_equal_cd:
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
  |
  |->vmeta_istype:
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
  |
  |//-- Arithmetic metamethods ---------------------------------------------
  |
  |->vmeta_arith_vno:
  |  llgc RB, PC_RB
  |  llgc RC, PC_RC
  |->vmeta_arith_vn:
  |  sllg RB, RB, 3(r0)
  |  sllg RC, RC, 3(r0)
  |  lay RB, 0(RB, BASE)
  |  lay RC, 0(RC, KBASE)
  |  j >1
  |
  |->vmeta_arith_nvo:
  |  llgc RC, PC_RC
  |  llgc RB, PC_RB
  |->vmeta_arith_nv:
  |  sllg RC, RC, 3(r0)
  |  sllg RB, RB, 3(r0)
  |  lay TMPR1, 0(RC, KBASE)
  |  lay RC, 0(RB, BASE)
  |  lgr RB, TMPR1
  |  j >1
  |
  |->vmeta_unm:
  |  llgh RD, PC_RD
  |  sllg RD, RD, 3(r0)
  |  la RC, 0(RD, BASE)
  |  lgr RB, RC
  |  j >1
  |
  |->vmeta_arith_vvo:
  |  llgc RB, PC_RB
  |  llgc RC, PC_RC
  |->vmeta_arith_vv:
  |  sllg RC, RC, 3(r0)
  |  sllg RB, RB, 3(r0)
  |  lay RB, 0(RB, BASE)
  |  lay RC, 0(RC, BASE)
  |1:
  |  llgc RA, PC_RA
  |  sllg RA, RA, 3(r0)
  |  lay RA, 0(RA, BASE)
  |  llgc CARG5, PC_OP			// Caveat: CARG5 == RD.
  |  lgr CARG2, RA
  |  lgr CARG3, RB
  |  // lgr CARG4, RC			// Caveat: CARG4 == RC (nop, so commented out).
  |  lg L:CARG1, SAVE_L
  |  stg BASE, L:CARG1->base
  |  lgr L:RB, L:CARG1
  |  stg PC, SAVE_PC
  |  brasl r14, extern lj_meta_arith // (lua_State *L, TValue *ra,*rb,*rc, BCReg op)
  |  // NULL (finished) or TValue * (metamethod) returned in r2 (CRET1).
  |  lg BASE, L:RB->base
  |  cghi CRET1, 0
  |  lgr RC, CRET1
  |  je ->cont_nop
  |
  |  // Call metamethod for binary op.
  |->vmeta_binop:
  |  // BASE = base, RC = new base, stack = cont/func/o1/o2
  |  lgr RA, RC
  |  sgr RC, BASE
  |  stg PC, -24(RA)			// [cont|PC]
  |  la PC, FRAME_CONT(RC)
  |  lghi NARGS:RD, 2+1			// 2 args for func(o1, o2).
  |  j ->vm_call_dispatch
  |
  |->vmeta_len:
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
  |
  |//-- Call metamethod ----------------------------------------------------
  |
  |->vmeta_call_ra:
  |  la RA, 16(RA, BASE)		// RA previously set to RA*8.
  |->vmeta_call:			// Resolve and call __call metamethod.
  |  // BASE = old base, RA = new base, RC = nargs+1, PC = return
  |  stg NARGS:RD, TMP_STACK		// Save RA, RC for us (not sure about this).
  |  lgr RB, RA
  |  lg L:CARG1, SAVE_L
  |  stg BASE, L:CARG1->base
  |  lay CARG2, -16(RA)
  |  sllg RD, RD, 3(r0)
  |  lay CARG3, -8(RA, RD)
  |  stg PC, SAVE_PC
  |  brasl r14, extern lj_meta_call	// (lua_State *L, TValue *func, TValue *top)
  |  lgr RA, RB
  |  lg L:RB, SAVE_L
  |  lg BASE, L:RB->base
  |  lg NARGS:RD, TMP_STACK
  |  lg LFUNC:RB, -16(RA)
  |  aghi NARGS:RD, 1			// 32-bit on x64.
  |  // This is fragile. L->base must not move, KBASE must always be defined.
  |  cgr KBASE, BASE			// Continue with CALLT if flag set.
  |  je ->BC_CALLT_Z
  |  cleartp LFUNC:RB
  |  lgr BASE, RA
  |  ins_call				// Otherwise call resolved metamethod.
  |
  |//-- Argument coercion for 'for' statement ------------------------------
  |
  |->vmeta_for:
  |  lg L:RB, SAVE_L
  |  stg BASE, L:RB->base
  |  lgr CARG2, RA
  |  lgr CARG1, RB
  |  stg PC, SAVE_PC
  |  brasl r14, extern lj_meta_for	// (lua_State *L, TValue *base)
  |  lg BASE, L:RB->base
  |  llgc OP, PC_OP
  |  llgc RA, PC_RA
  |  llgh RD, PC_RD
  |  sllg TMPR1, OP, 3(r0)
  |  lg TMPR1, GG_DISP2STATIC(TMPR1, DISPATCH)	// Retry FORI or JFORI.
  |  br TMPR1
  |
  |//-----------------------------------------------------------------------
  |//-- Fast functions -----------------------------------------------------
  |//-----------------------------------------------------------------------
  |
  |.macro .ffunc, name
  |->ff_ .. name:
  |.endmacro
  |
  |.macro .ffunc_1, name
  |->ff_ .. name:
  |  clfi NARGS:RD, 1+1; jl ->fff_fallback
  |.endmacro
  |
  |.macro .ffunc_2, name
  |->ff_ .. name:
  |  clfi NARGS:RD, 2+1; jl ->fff_fallback
  |.endmacro
  |
  |.macro .ffunc_n, name, op
  |  .ffunc_1 name
  |.endmacro
  |
  |.macro .ffunc_n, name
  |  .ffunc_n name, mvc
  |.endmacro
  |
  |.macro .ffunc_nn, name
  |  .ffunc_2 name
  |.endmacro
  |
  |// Inlined GC threshold check. Caveat: uses label 1.
  |.macro ffgccheck
  |.endmacro
  |
  |//-- Base library: checks -----------------------------------------------
  |
  |.ffunc_1 assert
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
  |
  |.ffunc_1 type
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
  |
  |//-- Base library: getters and setters ---------------------------------
  |
  |.ffunc_1 getmetatable
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
  |
  |.ffunc_2 setmetatable
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
  |
  |.ffunc_2 rawget
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
  |
  |//-- Base library: conversions ------------------------------------------
  |
  |.ffunc tonumber
  |  // Only handles the number case inline (without a base argument).
  |  clfi NARGS:RD, 1+1; jne ->fff_fallback	// Exactly one argument.
  |  lg RB, 0(BASE)
  |  checknumber RB, ->fff_fallback
  |  lg PC, -8(BASE)
  |  stg RB, -16(BASE)
  |  j ->fff_res1
  |
  |.ffunc_1 tostring
  |  // Only handles the string or number case inline.
  |  lg PC, -8(BASE)
  |  lg STR:RB, 0(BASE)
  |  checktp_nc STR:RB, LJ_TSTR, >3
  |  // A __tostring method in the string base metatable is ignored.
  |2:
  |  stg STR:RB, -16(BASE)
  |  j ->fff_res1
  |3:  // Handle numbers inline, unless a number base metatable is present.
  |  clfi ITYPE, LJ_TISNUM; jh ->fff_fallback_1
  |  lghi TMPR2, 0
  |  cg TMPR2, (DISPATCH_GL(gcroot[GCROOT_BASEMT_NUM]))(DISPATCH)
  |  jne ->fff_fallback
  |  ffgccheck				// Caveat: uses label 1.
  |  lg L:RB, SAVE_L
  |  stg BASE, L:RB->base		// Add frame since C call can throw.
  |  stg PC, SAVE_PC			// Redundant (but a defined value).
  |  lgr CARG2, BASE			// Otherwise: CARG2 == BASE
  |  lgr L:CARG1, L:RB
  |  brasl r14, extern lj_strfmt_number	// (lua_State *L, cTValue *o)
  |  // GCstr returned in r2 (CRET1).
  |  stg r0, 0(r0)
  |  lg BASE, L:RB->base
  |  settp STR:RB, CRET1, LJ_TSTR
  |  j <2
  |
  |//-- Base library: iterators -------------------------------------------
  |
  |.ffunc_1 next
  |
  |.ffunc_1 pairs
  |
  |.ffunc_2 ipairs_aux
  |->fff_res0:
  |
  |.ffunc_1 ipairs
  |
  |//-- Base library: catch errors ----------------------------------------
  |
  |.ffunc_1 pcall
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
  |
  |.ffunc_2 xpcall
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
  |
  |//-- Coroutine library --------------------------------------------------
  |
  |.macro coroutine_resume_wrap, resume
  |.if resume
  |.ffunc_1 coroutine_resume
  |.else
  |.ffunc coroutine_wrap_aux
  |.endif
  |.endmacro
  |
  |  coroutine_resume_wrap 1		// coroutine.resume
  |  coroutine_resume_wrap 0		// coroutine.wrap
  |
  |.ffunc coroutine_yield
  |
  |//-- Math library -------------------------------------------------------
  |
  |  .ffunc_1 math_abs
  |->fff_resbit:
  |->fff_resi:
  |->fff_resRB:
  |
  |.ffunc_n math_sqrt, sqrtsd
  |->fff_resxmm0:
  |
  |->fff_res1:
  |  lghi RD, 1+1
  |->fff_res:
  |  stg RD, SAVE_MULTRES
  |->fff_res_:
  |  tmll PC, FRAME_TYPE
  |  jne >7
  |5:
  |  llgc TMPR1, PC_RB
  |  clgr TMPR1, RD			// More results expected?
  |  jh >6
  |  // Adjust BASE. KBASE is assumed to be set for the calling frame.
  |  llgc RA, PC_RA
  |  lcgr RA, RA
  |  sllg RA, RA, 3(r0)
  |  lay BASE, -16(RA, BASE)		// base = base - (RA+2)*8
  |  ins_next
  |
  |6:  // Fill up results with nil.
  |  sllg TMPR1, RD, 3(r0)
  |  lghi TMPR2, LJ_TNIL
  |  stg TMPR2, -24(TMPR1, BASE)
  |  la RD, 1(RD)
  |  j <5
  |
  |7:  // Non-standard return case.
  |  lghi RA, -16			// Results start at BASE+RA = BASE-16.
  |  j ->vm_return
  |
  |.macro math_round, func
  |  .ffunc math_ .. func
  |.endmacro
  |
  |  math_round floor
  |  math_round ceil
  |
  |.ffunc math_log
  |
  |.macro math_extern, func
  |  .ffunc_n math_ .. func
  |.endmacro
  |
  |.macro math_extern2, func
  |  .ffunc_nn math_ .. func
  |.endmacro
  |
  |  math_extern log10
  |  math_extern exp
  |  math_extern sin
  |  math_extern cos
  |  math_extern tan
  |  math_extern asin
  |  math_extern acos
  |  math_extern atan
  |  math_extern sinh
  |  math_extern cosh
  |  math_extern tanh
  |  math_extern2 pow
  |  math_extern2 atan2
  |  math_extern2 fmod
  |
  |.ffunc_2 math_ldexp
  |
  |.ffunc_n math_frexp
  |
  |.ffunc_n math_modf
  |.macro math_minmax, name, cmovop, sseop
  |  .ffunc name
  |.endmacro
  |
  |  math_minmax math_min, cmovg, minsd
  |  math_minmax math_max, cmovl, maxsd
  |
  |//-- String library -----------------------------------------------------
  |
  |.ffunc string_byte			// Only handle the 1-arg case here.
  |  stg r0, 0(r0)
  |
  |.ffunc string_char			// Only handle the 1-arg case here.
  |  stg r0, 0(r0)
  |->fff_newstr:
  |  stg r0, 0(r0)
  |->fff_resstr:
  |  stg r0, 0(r0)
  |
  |.ffunc string_sub
  |  stg r0, 0(r0)
  |
  |->fff_emptystr:  // Range underflow.
  |  stg r0, 0(r0)
  |
  |.macro ffstring_op, name
  |  .ffunc_1 string_ .. name
  |.endmacro
  |
  |ffstring_op reverse
  |ffstring_op lower
  |ffstring_op upper
  |
  |//-- Bit library --------------------------------------------------------
  |
  |.macro .ffunc_bit, name, kind, fdef
  |  fdef name
  |.endmacro
  |
  |.macro .ffunc_bit, name, kind
  |  .ffunc_bit name, kind, .ffunc_1
  |.endmacro
  |
  |.ffunc_bit bit_tobit, 0
  |
  |.macro .ffunc_bit_op, name, ins
  |  .ffunc_bit name, 2
  |.endmacro
  |
  |.ffunc_bit_op bit_band, and
  |.ffunc_bit_op bit_bor, or
  |.ffunc_bit_op bit_bxor, xor
  |
  |.ffunc_bit bit_bswap, 1
  |
  |.ffunc_bit bit_bnot, 1
  |->fff_resbit:
  |
  |->fff_fallback_bit_op:
  |
  |.macro .ffunc_bit_sh, name, ins
  |  .ffunc_bit name, 1, .ffunc_2
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
  |.endmacro
  |
  |.ffunc_bit_sh bit_lshift, shl
  |.ffunc_bit_sh bit_rshift, shr
  |.ffunc_bit_sh bit_arshift, sar
  |.ffunc_bit_sh bit_rol, rol
  |.ffunc_bit_sh bit_ror, ror
  |
  |//-----------------------------------------------------------------------
  |
  |->fff_fallback_2:
  |  lghi NARGS:RD, 1+2			// Other args are ignored, anyway.
  |  j ->fff_fallback
  |->fff_fallback_1:
  |  lghi NARGS:RD, 1+1			// Other args are ignored, anyway.
  |->fff_fallback:			// Call fast function fallback handler.
  |  // BASE = new base, RD = nargs+1
  |  lg L:RB, SAVE_L
  |  lg PC, -8(BASE)			// Fallback may overwrite PC.
  |  stg PC, SAVE_PC			// Redundant (but a defined value).
  |  stg BASE, L:RB->base
  |  sllg RD, NARGS:RD, 3(r0)
  |  lay RD, -8(RD, BASE)
  |  la RA, (8*LUA_MINSTACK)(RD)	// Ensure enough space for handler.
  |  stg RD, L:RB->top
  |  lg CFUNC:RD, -16(BASE)
  |  cleartp CFUNC:RD
  |  clg RA, L:RB->maxstack
  |  jh >5				// Need to grow stack.
  |  lgr CARG1, L:RB
  |  lg TMPR1, CFUNC:RD->f
  |  basr r14, TMPR1			// (lua_State *L)
  |  lg BASE, L:RB->base
  |  // Either throws an error, or recovers and returns -1, 0 or nresults+1.
  |  lgr RD, CRET1
  |  cghi RD, 0; jh ->fff_res	// Returned nresults+1?
  |1:
  |  lg RA, L:RB->top
  |  sgr RA, BASE
  |  srlg RA, RA, 3(r0)
  |  cghi RD, 0
  |    la NARGS:RD, 1(RA)
  |    lg LFUNC:RB, -16(BASE)
  |  jne ->vm_call_tail			// Returned -1?
  |  cleartp LFUNC:RB
  |  ins_callt				// Returned 0: retry fast path.
  |
  |// Reconstruct previous base for vmeta_call during tailcall.
  |->vm_call_tail:
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
  |
  |->fff_gcstep:			// Call GC step function.
  |  // BASE = new base, RD = nargs+1
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
  |
  |//-----------------------------------------------------------------------
  |//-- Special dispatch targets -------------------------------------------
  |//-----------------------------------------------------------------------
  |
  |->vm_record:				// Dispatch target for recording phase.
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
  |
  |->vm_rethook:			// Dispatch target for return hooks.
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
  |
  |->vm_inshook:			// Dispatch target for instr/line hooks.
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
  |
  |->cont_hook:				// Continue from hook yield.
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
  |
  |->vm_hotloop:			// Hot loop counter underflow.
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
  |
  |->vm_callhook:			// Dispatch target for call hooks.
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
  |
  |->vm_hotcall:			// Hot call counter underflow.
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
  |
  |->cont_stitch:			// Trace stitching.
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
  |
  |->vm_profhook:			// Dispatch target for profiler hook.
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
  |
  |//-----------------------------------------------------------------------
  |//-- Trace exit handler -------------------------------------------------
  |//-----------------------------------------------------------------------
  |
  |// Called from an exit stub with the exit number on the stack.
  |// The 16 bit exit number is stored with two (sign-extended) push imm8.
  |->vm_exit_handler:
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
  |->vm_exit_interp:
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
  |
  |//-----------------------------------------------------------------------
  |//-- Math helper functions ----------------------------------------------
  |//-----------------------------------------------------------------------
  |
  |// FP value rounding. Called by math.floor/math.ceil fast functions.
  |// Value to round is in f0. May clobber f0-f7 and r0. Return address is r14.
  |.macro vm_round, name, mask
  |->name:
  |  // TODO: handle edge cases?
  |  lghi r0, 1
  |  cdfbr f1, r0
  |  didbr f0, f2, f1, mask // f0=remainder, f2=quotient.
  |  jnle >1
  |  ldr f0, f2
  |  br r14
  |1: // partial remainder (sanity check)
  |  stg r0, 0(r0)
  |.endmacro
  |
  |  vm_round vm_floor, 7 // Round towards -inf.
  |  vm_round vm_ceil,  6 // Round towards +inf.
  |  vm_round vm_trunc, 5 // Round towards 0.
  |
  |// FP modulo x%y. Called by BC_MOD* and vm_arith.
  |->vm_mod:
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
  |
  |// Args in xmm0/eax. Ret in xmm0. xmm0-xmm1 and eax modified.
  |->vm_powi_sse:
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
  |
  |//-----------------------------------------------------------------------
  |//-- Miscellaneous functions --------------------------------------------
  |//-----------------------------------------------------------------------
  |
  |// int lj_vm_cpuid(uint32_t f, uint32_t res[4])
  |->vm_cpuid:
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
  |
  |//-----------------------------------------------------------------------
  |//-- Assertions ---------------------------------------------------------
  |//-----------------------------------------------------------------------
  |
  |->assert_bad_for_arg_type:
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
#ifdef LUA_USE_ASSERT
#endif
  |
  |//-----------------------------------------------------------------------
  |//-- FFI helper functions -----------------------------------------------
  |//-----------------------------------------------------------------------
  |
  |// Handler for callback functions. Callback slot number in ah/al.
  |->vm_ffi_callback:
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
  |
  |->cont_ffi_callback:			// Return from FFI callback.
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
  |
  |->vm_ffi_call:			// Call C function via FFI.
  |// Note: vm_ffi_call must be the last function in this object file!
  |  stg r0, 0(r0)
  |  stg r0, 0(r0)
  |
  |//-----------------------------------------------------------------------
}

/* Generate the code for a single instruction. */
static void build_ins(BuildCtx *ctx, BCOp op, int defop)
{
  int vk = 0;
  (void)vk;
  |// Note: aligning all instructions does not pay off.
  |=>defop:

  switch (op) {

  /* -- Comparison ops ---------------------------------------------------- */

  /* Remember: all ops branch for a true comparison, fall through otherwise. */

  |.macro jmp_comp, lt, ge, le, gt, target
  ||switch (op) {
  ||case BC_ISLT:
  |   lt target
  ||break;
  ||case BC_ISGE:
  |   ge target
  ||break;
  ||case BC_ISLE:
  |   le target
  ||break;
  ||case BC_ISGT:
  |   gt target
  ||break;
  ||default: break;  /* Shut up GCC. */
  ||}
  |.endmacro

  case BC_ISLT: case BC_ISGE: case BC_ISLE: case BC_ISGT:
    |  // RA = src1, RD = src2, JMP with RD = target
    |  ins_AD
    |  sllg RA, RA, 3(r0)
    |  sllg RD, RD, 3(r0)
    |  ld f0, 0(RA, BASE)
    |  ld f1, 0(RD, BASE)
    |  lg RA, 0(RA, BASE)
    |  lg RD, 0(RD, BASE)
    |  srag ITYPE, RA, 47(r0)
    |  srag RB, RD, 47(r0)
    |
    |  clfi ITYPE, LJ_TISNUM; jne >7
    |  clfi RB, LJ_TISNUM; jne >8
    |  // Both are integers.
    |  la PC, 4(PC)
    |  cr RA, RD
    |  jmp_comp jhe, jl, jh, jle, >9
    |6:
    |  llgh RD, PC_RD
    |  branchPC RD
    |9:
    |  ins_next
    |
    |7:  // RA is not an integer.
    |  jh ->vmeta_comp
    |  // RA is a number.
    |  clfi RB, LJ_TISNUM; jl >1; jne ->vmeta_comp
    |  // RA is a number, RD is an integer.
    |  cdfbr f1, RD
    |  j >1
    |
    |8:  // RA is an integer, RD is not an integer.
    |  jh ->vmeta_comp
    |  // RA is an integer, RD is a number.
    |  cdfbr f0, RA
    |1:
    |  la PC, 4(PC)
    |  cdbr f0, f1
    |  // To preserve NaN semantics GE/GT branch on unordered, but LT/LE don't.
    |  jmp_comp jnl, jl, jnle, jle, <9
    |  j <6
    break;

  case BC_ISEQV: case BC_ISNEV:
    vk = op == BC_ISEQV;
    |  ins_AD	// RA = src1, RD = src2, JMP with RD = target
    |  sllg RD, RD, 3(r0)
    |  ld f1, 0(RD, BASE)
    |  lg RD, 0(RD, BASE)
    |  sllg RA, RA, 3(r0)
    |  ld f0, 0(RA, BASE)
    |  lg RA, 0(RA, BASE)
    |  la PC, 4(PC)
    |  srag RB, RD, 47(r0)
    |  srag ITYPE, RA, 47(r0)
    |  clfi RB, LJ_TISNUM; jne >7
    |  clfi ITYPE, LJ_TISNUM; jne >8
    |  cr RD, RA
    if (vk) {
      |  jne >9
    } else {
      |  je >9
    }
    |  llgh RD, PC_RD
    |  branchPC RD
    |9:
    |  ins_next
    |
    |7:  // RD is not an integer.
    |  jh >5
    |  // RD is a number.
    |  clfi ITYPE, LJ_TISNUM; jl >1; jne >5
    |  // RD is a number, RA is an integer.
    |  cdfbr f0, RA
    |  j >1
    |
    |8:  // RD is an integer, RA is not an integer.
    |  jh >5
    |  // RD is an integer, RA is a number.
    |  cdfbr f1, RD
    |  j >1
    |
    |1:
    |  cdbr f0, f1
    |4:
  iseqne_fp:
    if (vk) {
      |  jne >2				// Unordered means not equal.
    } else {
      |  je >1				// Unordered means not equal.
    }
  iseqne_end:
    if (vk) {
      |1:				// EQ: Branch to the target.
      |  llgh RD, PC_RD
      |  branchPC RD
      |2:				// NE: Fallthrough to next instruction.
      |.if not FFI
      |3:
      |.endif
    } else {
      |.if not FFI
      |3:
      |.endif
      |2:				// NE: Branch to the target.
      |  llgh RD, PC_RD
      |  branchPC RD
      |1:				// EQ: Fallthrough to next instruction.
    }
    if (LJ_DUALNUM && (op == BC_ISEQV || op == BC_ISNEV ||
		       op == BC_ISEQN || op == BC_ISNEN)) {
      |  j <9
    } else {
      |  ins_next
    }
    |
    if (op == BC_ISEQV || op == BC_ISNEV) {
      |5:  // Either or both types are not numbers.
      |.if FFI
      |  clfi RB, LJ_TCDATA; je ->vmeta_equal_cd
      |  clfi ITYPE, LJ_TCDATA; je ->vmeta_equal_cd
      |.endif
      |  cgr RA, RD
      |  je <1				// Same GCobjs or pvalues?
      |  cr RB, ITYPE
      |  jne <2				// Not the same type?
      |  clfi RB, LJ_TISTABUD
      |  jh <2				// Different objects and not table/ud?
      |
      |  // Different tables or userdatas. Need to check __eq metamethod.
      |  // Field metatable must be at same offset for GCtab and GCudata!
      |  cleartp TAB:RA
      |  lg TAB:RB, TAB:RA->metatable
      |  cghi TAB:RB, 0
      |  je <2				// No metatable?
      |  llgc TMPR2, TAB:RB->nomm
      |  tmll TMPR2, 1<<MM_eq
      |  jne <2				// Or 'no __eq' flag set?
      if (vk) {
	|  lghi RB, 0			// ne = 0 // TODO: should be 32-bit?
      } else {
	|  lghi RB, 1			// ne = 1 // TODO: should be 32-bit?
      }
      |  j ->vmeta_equal		// Handle __eq metamethod.
    } else {
      |.if FFI
      |3:
      |  clfi ITYPE, LJ_TCDATA
      if (LJ_DUALNUM && vk) {
	|  jne <9
      } else {
	|  jne <2
      }
      |  j ->vmeta_equal_cd
      |.endif
    }
    break;
  case BC_ISEQS: case BC_ISNES:
    vk = op == BC_ISEQS;
    |  ins_AND	// RA = src, RD = str const, JMP with RD = target
    |  sllg RA, RA, 3(r0)
    |  sllg RD, RD, 3(r0)
    |  lg RB, 0(RA, BASE)
    |  la PC, 4(PC)
    |  checkstr RB, >3
    |  cg RB, 0(RD, KBASE)
  iseqne_test:
    if (vk) {
      |  jne >2
    } else {
      |  je >1
    }
    goto iseqne_end;
  case BC_ISEQN: case BC_ISNEN:
    vk = op == BC_ISEQN;
    |  ins_AD	// RA = src, RD = num const, JMP with RD = target
    |  sllg RA, RA, 3(r0)
    |  sllg RD, RD, 3(r0)
    |  ld f0, 0(RA, BASE)
    |  lg RB, 0(RA, BASE)
    |  ld f1, 0(RD, KBASE)
    |  lg RD, 0(RD, KBASE)
    |  la PC, 4(PC)
    |  checkint RB, >7
    |  checkint RD, >8
    |  cr RB, RD
    if (vk) {
      |  jne >9
    } else {
      |  je >9
    }
    |  llgh RD, PC_RD
    |  branchPC RD
    |9:
    |  ins_next
    |
    |7:  // RA is not an integer.
    |  jh >3
    |  // RA is a number.
    |  checkint RD, >1
    |  // RA is a number, RD is an integer.
    |  cdfbr f1, RD
    |  j >1
    |
    |8:  // RA is an integer, RD is a number.
    |  cdfbr f0, RB
    |  cdbr f0, f1
    |  j >4
    |1:
    |  cdbr f0, f1
    |4:
    goto iseqne_fp;
  case BC_ISEQP: case BC_ISNEP:
    vk = op == BC_ISEQP;
    |  ins_AND	// RA = src, RD = primitive type (~), JMP with RD = target
    |  sllg RA, RA, 3(r0)
    |  lg RB, 0(RA, BASE)
    |  srag RB, RB, 47(r0)
    |  la PC, 4(PC)
    |  cr RB, RD
    if (!LJ_HASFFI) goto iseqne_test;
    if (vk) {
      |  jne >3
      |  llgh RD, PC_RD
      |  branchPC RD
      |2:
      |  ins_next
      |3:
      |  cghi RB, LJ_TCDATA; jne <2
      |  j ->vmeta_equal_cd
    } else {
      |  je >2
      |  cghi RB, LJ_TCDATA; je ->vmeta_equal_cd
      |  llgh RD, PC_RD
      |  branchPC RD
      |2:
      |  ins_next
    }
    break;

  /* -- Unary test and copy ops ------------------------------------------- */

  case BC_ISTC: case BC_ISFC: case BC_IST: case BC_ISF:
    |  ins_AD	// RA = dst or unused, RD = src, JMP with RD = target
    |  sllg RD, RD, 3(r0)
    |  sllg RA, RA, 3(r0)
    |  lg ITYPE, 0(RD, BASE)
    |  la PC, 4(PC)
    if (op == BC_ISTC || op == BC_ISFC) {
      |  lgr RB, ITYPE
    }
    |  srag ITYPE, ITYPE, 47(r0)
    |  clfi ITYPE, LJ_TISTRUECOND
    if (op == BC_IST || op == BC_ISTC) {
      |  jhe >1
    } else {
      |  jl >1
    }
    if (op == BC_ISTC || op == BC_ISFC) {
      |  stg RB, 0(RA, BASE)
    }
    |  llgh RD, PC_RD
    |  branchPC RD
    |1:					// Fallthrough to the next instruction.
    |  ins_next
    break;
  case BC_ISTYPE:
    |  stg r0, 0(r0)
    |  stg r0, 0(r0)
    break;
  case BC_ISNUM:
    |  stg r0, 0(r0)
    |  stg r0, 0(r0)
    break;
  case BC_MOV:
    |  ins_AD	// RA = dst, RD = src
    |  sllg RD, RD, 3(r0)
    |  lg RB, 0(RD, BASE)
    |  sllg RA, RA, 3(r0)
    |  stg RB, 0(RA, BASE)
    |  ins_next_
    break;
  case BC_NOT:
    |  ins_AD	// RA = dst, RD = src
    |  sllg RD, RD, 3(r0)
    |  sllg RA, RA, 3(r0)
    |  lg RB, 0(RD, BASE)
    |  srag RB, RB, 47(r0)
    |  load_false RC
    |  cghi RB, LJ_TTRUE
    |  je >1 // TODO: Maybe do something fancy to avoid the jump?
    |  load_true RC
    |1:
    |  stg RC, 0(RA, BASE)
    |  ins_next
    break;
  case BC_UNM:
    |  ins_AD	// RA = dst, RD = src
    |  sllg RA, RA, 3(r0)
    |  sllg RD, RD, 3(r0)
    |  lg RB, 0(RD, BASE)
    |  checkint RB, >3
    |  lcr RB, RB; jo >2
    |1:
    |  stg RB, 0(RA, BASE)
    |  ins_next
    |2:
    |  llihh RB, 0x41e0 // (double)2^31
    |  j <1
    |3:
    |  jh ->vmeta_unm
    |  // Toggle sign bit.
    |  llihh TMPR2, 0x8000
    |  xgr RB, TMPR2
    |  j <1
    break;
  case BC_LEN:
    |  stg r0, 0(r0)
    |  stg r0, 0(r0)
    break;

  /* -- Binary ops -------------------------------------------------------- */

    |.macro ins_arithpre
    |  ins_ABC
    |  sllg RB, RB, 3(r0)
    |  sllg RC, RC, 3(r0)
    |  sllg RA, RA, 3(r0)
    |.endmacro
    |
    |.macro ins_arithfp, ins
    |  ins_arithpre
    ||vk = ((int)op - BC_ADDVN) / (BC_ADDNV-BC_ADDVN);
    ||switch (vk) {
    ||case 0:
    |   ld f0, 0(RB, BASE)
    |   ld f1, 0(RC, KBASE)
    |   lg RB, 0(RB, BASE)
    |   lg RC, 0(RC, KBASE)
    |   checknumtp RB, ->vmeta_arith_vno
    |   checknumtp RC, ->vmeta_arith_vno
    |   ins f0, f1
    ||  break;
    ||case 1:
    |   ld f1, 0(RB, BASE)
    |   ld f0, 0(RC, KBASE)
    |   lg RB, 0(RB, BASE)
    |   lg RC, 0(RC, KBASE)
    |   checknumtp RB, ->vmeta_arith_nvo
    |   checknumtp RC, ->vmeta_arith_nvo
    |   ins f0, f1
    ||  break;
    ||default:
    |   ld f0, 0(RB, BASE)
    |   ld f1, 0(RC, BASE)
    |   lg RB, 0(RB, BASE)
    |   lg RC, 0(RC, BASE)
    |   checknumtp RB, ->vmeta_arith_vvo
    |   checknumtp RC, ->vmeta_arith_vvo
    |   ins f0, f1
    ||  break;
    ||}
    |  std f0, 0(RA, BASE)
    |  ins_next
    |.endmacro
    |
    |.macro ins_arithdn, intins
    |  ins_arithpre
    ||vk = ((int)op - BC_ADDVN) / (BC_ADDNV-BC_ADDVN);
    ||switch (vk) {
    ||case 0:
    |   lg RB, 0(RB, BASE)
    |   lg RC, 0(RC, KBASE)
    |   checkint RB, ->vmeta_arith_vno
    |   checkint RC, ->vmeta_arith_vno
    |   intins RB, RC; jo ->vmeta_arith_vno
    ||  break;
    ||case 1:
    |   lg RB, 0(RB, BASE)
    |   lg RC, 0(RC, KBASE)
    |   checkint RB, ->vmeta_arith_nvo
    |   checkint RC, ->vmeta_arith_nvo
    |   intins RC, RB; jo ->vmeta_arith_nvo
    ||  break;
    ||default:
    |   lg RB, 0(RB, BASE)
    |   lg RC, 0(RC, BASE)
    |   checkint RB, ->vmeta_arith_vvo
    |   checkint RC, ->vmeta_arith_vvo
    |   intins RB, RC; jo ->vmeta_arith_vvo
    ||  break;
    ||}
    ||if (vk == 1) {
    |   // setint RC
    |   stg RC, 0(RA, BASE)
    ||} else {
    |   // setint RB
    |   stg RB, 0(RA, BASE)
    ||}
    |  ins_next
    |.endmacro

    |  // RA = dst, RB = src1 or num const, RC = src2 or num const
  case BC_ADDVN: case BC_ADDNV: case BC_ADDVV:
    |  ins_arithdn ar
    break;
  case BC_SUBVN: case BC_SUBNV: case BC_SUBVV:
    |  ins_arithdn sr
    break;
  case BC_MULVN: case BC_MULNV: case BC_MULVV:
    |  ins_arithpre
    |  // For multiplication we use msgfr and check if the result
    |  // fits in an int32_t.
    switch(op) {
    case BC_MULVN:
      |  lg RB, 0(RB, BASE)
      |  lg RC, 0(RC, KBASE)
      |  checkint RB, ->vmeta_arith_vno
      |  checkint RC, ->vmeta_arith_vno
      |  lgfr RB, RB
      |  msgfr RB, RC
      |  lgfr RC, RB
      |  cgr RB, RC; jne ->vmeta_arith_vno
      break;
    case BC_MULNV:
      |  lg RB, 0(RB, BASE)
      |  lg RC, 0(RC, KBASE)
      |  checkint RB, ->vmeta_arith_nvo
      |  checkint RC, ->vmeta_arith_nvo
      |  lgfr RB, RB
      |  msgfr RB, RC
      |  lgfr RC, RB
      |  cgr RB, RC; jne ->vmeta_arith_nvo
      break;
    default:
      |  lg RB, 0(RB, BASE)
      |  lg RC, 0(RC, BASE)
      |  checkint RB, ->vmeta_arith_vvo
      |  checkint RC, ->vmeta_arith_vvo
      |  lgfr RB, RB
      |  msgfr RB, RC
      |  lgfr RC, RB
      |  cgr RB, RC; jne ->vmeta_arith_vvo
      break;
    }
    |  llgfr RB, RB
    |  setint RB
    |  stg RB, 0(RA, BASE)
    |  ins_next
    break;
  case BC_DIVVN: case BC_DIVNV: case BC_DIVVV:
    |  ins_arithfp ddbr
    break;
  // TODO: implement fast mod operation.
  // x86_64 does floating point mod, however it might be better to use integer mod.
  case BC_MODVN:
    |  j ->vmeta_arith_vno
    break;
  case BC_MODNV:
    |  j ->vmeta_arith_nvo
    break;
  case BC_MODVV:
    |  j ->vmeta_arith_vvo
    break;
  case BC_POW:
    |  stg r0, 0(r0)
    |  stg r0, 0(r0)
    break;
  case BC_CAT:
    |  stg r0, 0(r0)
    |  stg r0, 0(r0)
    break;

  /* -- Constant ops ------------------------------------------------------ */

  case BC_KSTR:
    |  ins_AND	// RA = dst, RD = str const (~)
    |  sllg RD, RD, 3(r0)
    |  lg RD, 0(RD, KBASE)
    |  settp RD, LJ_TSTR
    |  sllg RA, RA, 3(r0)
    |  stg RD, 0(RA, BASE)
    |  ins_next
    break;
  case BC_KCDATA:
    |  stg r0, 0(r0)
    |  stg r0, 0(r0)
    break;
  case BC_KSHORT:
    |  ins_AD	// RA = dst, RD = signed int16 literal
    |  // Assumes DUALNUM.
    |  lhr RD, RD			// Sign-extend literal to 32-bits.
    |  setint RD
    |  sllg RA, RA, 3(r0)
    |  stg RD, 0(RA, BASE)
    |  ins_next
    break;
  case BC_KNUM:
    |  ins_AD	// RA = dst, RD = num const
    |  sllg RD, RD, 3(r0)
    |  ld f0, 0(RD, KBASE)
    |  sllg RA, RA, 3(r0)
    |  std f0, 0(RA, BASE)
    |  ins_next
    break;
  case BC_KPRI:
    |  ins_AD	// RA = dst, RD = primitive type (~)
    |  sllg RA, RA, 3(r0)
    |  sllg RD, RD, 47(r0)
    |  lghi TMPR2, -1
    |  xgr RD, TMPR2 // not
    |  stg RD, 0(RA, BASE)
    |  ins_next
    break;
  case BC_KNIL:
    |  stg r0, 0(r0)
    |  stg r0, 0(r0)
    break;
  case BC_UGET:
    |  stg r0, 0(r0)
    |  stg r0, 0(r0)
    break;
  case BC_USETV:
    |  stg r0, 0(r0)
    |  stg r0, 0(r0)
    break;
  case BC_USETS:
    |  stg r0, 0(r0)
    |  stg r0, 0(r0)
    break;
  case BC_USETN:
    |  stg r0, 0(r0)
    |  stg r0, 0(r0)
    break;
  case BC_USETP:
    |  stg r0, 0(r0)
    |  stg r0, 0(r0)
    break;
  case BC_UCLO:
    |  stg r0, 0(r0)
    |  stg r0, 0(r0)
    break;
  case BC_FNEW:
    |  ins_AND	// RA = dst, RD = proto const (~) (holding function prototype)
    |  lg L:RB, SAVE_L
    |  stg BASE, L:RB->base
    |  lg CARG3, -16(BASE)
    |  cleartp CARG3
    |  sllg RD, RD, 3(r0)
    |  lg CARG2, 0(RD, KBASE)		// Fetch GCproto *.
    |  lgr CARG1, L:RB
    |  stg PC, SAVE_PC
    |  // (lua_State *L, GCproto *pt, GCfuncL *parent)
    |  brasl r14, extern lj_func_newL_gc
    |  // GCfuncL * returned in r2 (CRET1).
    |  lg BASE, L:RB->base
    |  llgc RA, PC_RA
    |  sllg RA, RA, 3(r0)
    |  settp LFUNC:CRET1, LJ_TFUNC
    |  stg LFUNC:CRET1, 0(RA, BASE)
    |  ins_next
    break;
  case BC_TNEW:
    |  ins_AD	// RA = dst, RD = hbits|asize
    |  lg L:RB, SAVE_L
    |  stg BASE, L:RB->base
    |  lg RA, (DISPATCH_GL(gc.total))(DISPATCH)
    |  clg RA, (DISPATCH_GL(gc.threshold))(DISPATCH)
    |  stg PC, SAVE_PC
    |  jhe >5
    |1:
    |  srlg CARG3, RD, 11(r0)
    |  llill TMPR2, 0x7ff
    |  nr RD, TMPR2
    |  cr RD, TMPR2
    |  je >3
    |2:
    |  lgr L:CARG1, L:RB
    |  llgfr CARG2, RD
    |  brasl r14, extern lj_tab_new  // (lua_State *L, uint32_t asize, uint32_t hbits)
    |  // Table * returned in r2 (CRET1).
    |  lg BASE, L:RB->base
    |  llgc RA, PC_RA
    |  sllg RA, RA, 3(r0)
    |  settp TAB:CRET1, LJ_TTAB
    |  stg TAB:CRET1, 0(RA, BASE)
    |  ins_next
    |3:  // Turn 0x7ff into 0x801.
    |  llill RD, 0x801
    |  j <2
    |5:
    |  lgr L:CARG1, L:RB
    |  brasl r14, extern lj_gc_step_fixtop	// (lua_State *L)
    |  llgh RD, PC_RD
    |  j <1
    break;
  case BC_TDUP:
    |  ins_AND	// RA = dst, RD = table const (~) (holding template table)
    |  lg L:RB, SAVE_L
    |  lg RA, (DISPATCH_GL(gc.total))(DISPATCH)
    |  stg PC, SAVE_PC
    |  clg RA, (DISPATCH_GL(gc.threshold))(DISPATCH)
    |  stg BASE, L:RB->base
    |  jhe >3
    |2:
    |  sllg RD, RD, 3(r0)
    |  lg TAB:CARG2, 0(RD, KBASE)
    |  lgr L:CARG1, L:RB
    |  brasl r14, extern lj_tab_dup		// (lua_State *L, Table *kt)
    |  // Table * returned in r2 (CRET1).
    |  lg BASE, L:RB->base
    |  llgc RA, PC_RA
    |  settp TAB:CRET1, LJ_TTAB
    |  sllg RA, RA, 3(r0)
    |  stg TAB:CRET1, 0(RA, BASE)
    |  ins_next
    |3:
    |  lgr L:CARG1, L:RB
    |  brasl r14, extern lj_gc_step_fixtop	// (lua_State *L)
    |  llgh RD, PC_RD				// Need to reload RD.
    |  lghi TMPR2, -1
    |  xgr RD, TMPR2				// not RD
    |  j <2
    break;

  case BC_GGET:
    |  ins_AND	// RA = dst, RD = str const (~)
    |  lg LFUNC:RB, -16(BASE)
    |  cleartp LFUNC:RB
    |  lg TAB:RB, LFUNC:RB->env
    |  sllg TMPR1, RD, 3(r0)
    |  lg STR:RC, 0(TMPR1, KBASE)
    |  j ->BC_TGETS_Z
    break;
  case BC_GSET:
    |  ins_AND	// RA = src, RD = str const (~)
    |  lg LFUNC:RB, -16(BASE)
    |  cleartp LFUNC:RB
    |  lg TAB:RB, LFUNC:RB->env
    |  sllg TMPR1, RD, 3(r0)
    |  lg STR:RC, 0(TMPR1, KBASE)
    |  j ->BC_TSETS_Z
    break;

  case BC_TGETV:
    |  ins_ABC	// RA = dst, RB = table, RC = key
    |  sllg RB, RB, 3(r0)
    |  lg TAB:RB, 0(RB, BASE)
    |  sllg RC, RC, 3(r0)
    |  lg RC, 0(RC, BASE)
    |  checktab TAB:RB, ->vmeta_tgetv
    |
    |  // Integer key?
    |  checkint RC, >5
    |  cl RC, TAB:RB->asize		// Takes care of unordered, too.
    |  jhe ->vmeta_tgetv		// Not in array part? Use fallback.
    |  llgfr RC, RC
    |  sllg RC, RC, 3(r0)
    |  ag RC, TAB:RB->array
    |  // Get array slot.
    |  lg ITYPE, 0(RC)
    |  cghi ITYPE, LJ_TNIL		// Avoid overwriting RB in fastpath.
    |  je >2
    |1:
    |  sllg RA, RA, 3(r0)
    |  stg ITYPE, 0(RA, BASE)
    |  ins_next
    |
    |2:  // Check for __index if table value is nil.
    |  lg TAB:TMPR1, TAB:RB->metatable
    |  cghi TAB:TMPR1, 0
    |  je <1
    |  llgc TMPR2, TAB:TMPR1->nomm
    |  tmll TMPR2, 1<<MM_index
    |  je ->vmeta_tgetv			// 'no __index' flag NOT set: check.
    |  j <1
    |
    |5:  // String key?
    |  cghi ITYPE, LJ_TSTR; jne ->vmeta_tgetv
    |  cleartp STR:RC
    |  j ->BC_TGETS_Z
    break;
  case BC_TGETS:
    |  ins_ABC
    |  sllg RB, RB, 3(r0)
    |  lg TAB:RB, 0(RB, BASE)
    |  lghi TMPR1, -1
    |  xgr RC, TMPR1
    |  sllg RC, RC, 3(r0)
    |  lg STR:RC, 0(RC, BASE)
    |  checktab TAB:RB, ->vmeta_tgets
    |->BC_TGETS_Z:	// RB = GCtab *, RC = GCstr *
    |  l TMPR1, TAB:RB->hmask
    |  n TMPR1, STR:RC->hash
    |  lgfr TMPR1, TMPR1
    |  mghi TMPR1, #NODE // TODO: not sure about this one, original: imul TMPRd, #NODE
    |  ag NODE:TMPR1, TAB:RB->node
    |  settp ITYPE, STR:RC, LJ_TSTR
    |1:
    |  cg ITYPE, NODE:TMPR1->key
    |  jne >4
    |  // Get node value.
    |  lg ITYPE, NODE:TMPR1->val
    |  cghi ITYPE, LJ_TNIL
    |  je >5				// Key found, but nil value?
    |2:
    |  sllg RA, RA, 3(r0)
    |  stg ITYPE, 0(RA, BASE)
    |  ins_next
    |
    |4:  // Follow hash chain.
    |  lg NODE:TMPR1, NODE:TMPR1->next
    |  cghi NODE:TMPR1, 0
    |  jne <1
    |  // End of hash chain: key not found, nil result.
    |  lghi ITYPE, LJ_TNIL
    |
    |5:  // Check for __index if table value is nil.
    |  lg TAB:TMPR1, TAB:RB->metatable
    |  cghi TAB:TMPR1, 0
    |  je <2				// No metatable: done.
    |  llgc TMPR2, TAB:TMPR1->nomm
    |  tmll TMPR2, 1<<MM_index
    |  jne <2				// 'no __index' flag set: done.
    |  j ->vmeta_tgets			// Caveat: preserve STR:RC.
    break;
  case BC_TGETB:
    |  ins_ABC	// RA = dst, RB = table, RC = byte literal
    |  sllg RB, RB, 3(r0)
    |  lg TAB:RB, 0(RB, BASE)
    |  checktab TAB:RB, ->vmeta_tgetb
    |  cl RC, TAB:RB->asize
    |  jhe ->vmeta_tgetb
    |  sllg RC, RC, 3(r0)
    |  ag RC, TAB:RB->array
    |  // Get array slot.
    |  lg ITYPE, 0(RC)
    |  cghi ITYPE, LJ_TNIL
    |  je >2
    |1:
    |  sllg RA, RA, 3(r0)
    |  stg ITYPE, 0(RA, BASE)
    |  ins_next
    |
    |2:  // Check for __index if table value is nil.
    |  lg TAB:TMPR1, TAB:RB->metatable
    |  cghi TAB:TMPR1, 0
    |  je <1
    |  llgc TMPR2, TAB:TMPR1->nomm
    |  tmll TMPR2, 1<<MM_index
    |  je ->vmeta_tgetb			// 'no __index' flag NOT set: check.
    |  j <1
    break;
  case BC_TGETR:
    |  stg r0, 0(r0)
    |  stg r0, 0(r0)
    break;

  case BC_TSETV:
    |  ins_ABC	// RA = src, RB = table, RC = key
    |  sllg RB, RB, 3(r0)
    |  lg TAB:RB, 0(RB, BASE)
    |  sllg RC, RC, 3(r0)
    |  lg RC, 0(RC, BASE)
    |  checktab TAB:RB, ->vmeta_tsetv
    |
    |  // Integer key?
    |  checkint RC, >5
    |  cl RC, TAB:RB->asize		// Takes care of unordered, too.
    |  jhe ->vmeta_tsetv
    |  llgfr RC, RC
    |  sllg RC, RC, 3(r0)
    |  ag RC, TAB:RB->array
    |  lghi TMPR2, LJ_TNIL
    |  cg TMPR2, 0(RC)
    |  je >3				// Previous value is nil?
    |1:
    |  llgc TMPR1, TAB:RB->marked
    |  tmll TMPR1, LJ_GC_BLACK			// isblack(table)
    |  jne >7
    |2:  // Set array slot.
    |  sllg RA, RA, 3(r0)
    |  lg RB, 0(RA, BASE)
    |  stg RB, 0(RC)
    |  ins_next
    |
    |3:  // Check for __newindex if previous value is nil.
    |  lg TAB:TMPR1, TAB:RB->metatable
    |  cghi TAB:TMPR1, 0
    |  je <1
    |  llgc TMPR2, TAB:TMPR1->nomm
    |  tmll TMPR2, 1<<MM_newindex
    |  je ->vmeta_tsetv			// 'no __newindex' flag NOT set: check.
    |  j <1
    |
    |5:  // String key?
    |  cghi ITYPE, LJ_TSTR; jne ->vmeta_tsetv
    |  cleartp STR:RC
    |  j ->BC_TSETS_Z
    |
    |7:  // Possible table write barrier for the value. Skip valiswhite check.
    |  barrierback TAB:RB, TMPR1
    |  j <2
    break;
  case BC_TSETS:
    |  stg r0, 0(r0)
    |
    |->BC_TSETS_Z:	// RB = GCtab *, RC = GCstr *
    |  l TMPR1, TAB:RB->hmask
    |  n TMPR1, STR:RC->hash
    |  lgfr TMPR1, TMPR1
    |  mghi TMPR1, #NODE
    |  xr TMPR2, TMPR2
    |  stc TMPR2, TAB:RB->nomm		// Clear metamethod cache.
    |  ag NODE:TMPR1, TAB:RB->node
    |  settp ITYPE, STR:RC, LJ_TSTR
    |1:
    |  cg ITYPE, NODE:TMPR1->key
    |  jne >5
    |  // Ok, key found. Assumes: offsetof(Node, val) == 0
    |  lghi TMPR2, LJ_TNIL
    |  cg TMPR2, 0(TMPR1)
    |  je >4				// Previous value is nil?
    |2:
    |  llgc TMPR2, TAB:RB->marked
    |  tmll TMPR2, LJ_GC_BLACK			// isblack(table)
    |  jne >7
    |3:  // Set node value.
    |  sllg RA, RA, 3(r0)
    |  lg ITYPE, 0(RA, BASE)
    |  stg ITYPE, 0(TMPR1)
    |  ins_next
    |
    |4:  // Check for __newindex if previous value is nil.
    |  lg TAB:ITYPE, TAB:RB->metatable
    |  cghi TAB:ITYPE, 0
    |  je <2
    |  llgc TMPR2, TAB:ITYPE->nomm
    |  tmll TMPR2, 1<<MM_newindex
    |  je ->vmeta_tsets			// 'no __newindex' flag NOT set: check.
    |  j <2
    |
    |5:  // Follow hash chain.
    |  lg NODE:TMPR1, NODE:TMPR1->next
    |  cghi NODE:TMPR1, 0
    |  jne <1
    |  // End of hash chain: key not found, add a new one.
    |
    |  // But check for __newindex first.
    |  lg TAB:TMPR1, TAB:RB->metatable
    |  cghi TAB:TMPR1, 0
    |  je >6				// No metatable: continue.
    |  llgc TMPR2, TAB:TMPR1->nomm
    |  tmll TMPR2, 1<<MM_newindex
    |  je ->vmeta_tsets			// 'no __newindex' flag NOT set: check.
    |6:
    |  stg ITYPE, TMP_STACK
    |  lg L:CARG1, SAVE_L
    |  stg BASE, L:CARG1->base
    |  la CARG3, TMP_STACK		// TODO: lea CARG3, ITYPE... not sure.
    |  lgr CARG2, TAB:RB
    |  stg PC, SAVE_PC
    |  brasl r14, extern lj_tab_newkey	// (lua_State *L, GCtab *t, TValue *k)
    |  // Handles write barrier for the new key. TValue * returned in r2 (CRET1).
    |  lgr TMPR1, CRET1
    |  lg L:CRET1, SAVE_L
    |  lg BASE, L:CRET1->base
    |  llgc RA, PC_RA
    |  j <2				// Must check write barrier for value.
    |
    |7:  // Possible table write barrier for the value. Skip valiswhite check.
    |  barrierback TAB:RB, ITYPE
    |  j <3
    break;
  case BC_TSETB:
    |  ins_ABC	// RA = src, RB = table, RC = byte literal
    |  sllg RB, RB, 3(r0)
    |  lg TAB:RB, 0(RB, BASE)
    |  checktab TAB:RB, ->vmeta_tsetb
    |  cl RC, TAB:RB->asize
    |  jhe ->vmeta_tsetb
    |  sllg RC, RC, 3(r0)
    |  ag RC, TAB:RB->array
    |  lghi TMPR2, LJ_TNIL
    |  cg TMPR2, 0(RC)
    |  je >3				// Previous value is nil?
    |1:
    |  llgc TMPR1, TAB:RB->marked
    |  tmll TMPR1, LJ_GC_BLACK		// isblack(table)
    |  jne >7
    |2:	 // Set array slot.
    |  sllg RA, RA, 3(r0)
    |  lg ITYPE, 0(RA, BASE)
    |  stg ITYPE, 0(RC)
    |  ins_next
    |
    |3:  // Check for __newindex if previous value is nil.
    |  lg TAB:TMPR1, TAB:RB->metatable
    |  cghi TAB:TMPR1, 0
    |  je <1
    |  llgc TMPR2, TAB:TMPR1->nomm
    |  tmll TMPR2, 1<<MM_newindex
    |  je ->vmeta_tsetb			// 'no __newindex' flag NOT set: check.
    |  j <1
    |
    |7:  // Possible table write barrier for the value. Skip valiswhite check.
    |  barrierback TAB:RB, TMPR1
    |  j <2
    break;
  case BC_TSETR:
    |  stg r0, 0(r0)
    |  stg r0, 0(r0)
    break;
  case BC_TSETM:
    |  stg r0, 0(r0)
    |  stg r0, 0(r0)
    break;

  /* -- Calls and vararg handling ----------------------------------------- */

  case BC_CALL: case BC_CALLM:
    |  ins_A_C	// RA = base, (RB = nresults+1,) RC = nargs+1 | extra_nargs
    |  lgr RD, RC
    if (op == BC_CALLM) {
      |  ag NARGS:RD, SAVE_MULTRES			// TODO: MULTRES is 32-bit on x64
    }
    |  sllg RA, RA, 3(r0)
    |  lg LFUNC:RB, 0(BASE, RA)
    |  checkfunc LFUNC:RB, ->vmeta_call_ra
    |  la BASE, 16(RA, BASE)
    |  ins_call
    break;

  case BC_CALLMT:
    |  stg r0, 0(r0)
    |  stg r0, 0(r0)
    break;
  case BC_CALLT:
    |  ins_AD	// RA = base, RD = nargs+1
    |  sllg RA, RA, 3(r0)
    |  la RA, 16(RA, BASE)
    |  lgr KBASE, BASE			// Use KBASE for move + vmeta_call hint.
    |  lg LFUNC:RB, -16(RA)
    |  checktp_nc LFUNC:RB, LJ_TFUNC, ->vmeta_call
    |->BC_CALLT_Z:
    |  lg PC, -8(BASE)
    |  tmll PC, FRAME_TYPE
    |  jne >7
    |1:
    |  stg LFUNC:RB, -16(BASE)		// Copy func+tag down, reloaded below.
    |  stg NARGS:RD, SAVE_MULTRES	// 32-bit on x64.
    |  aghi NARGS:RD, -1
    |  je >3
    |2:  // Move args down.
    |  // TODO: mvc or something here?
    |  lg RB, 0(RA)
    |  la RA, 8(RA)
    |  stg RB, 0(KBASE)
    |  la KBASE, 8(KBASE)
    |  // TODO: replace decrement/branch with brctg
    |  aghi NARGS:RD, -1
    |  jne <2
    |
    |  lg LFUNC:RB, -16(BASE)
    |3:
    |  cleartp LFUNC:RB
    |  lg NARGS:RD, SAVE_MULTRES
    |  llgc TMPR1, LFUNC:RB->ffid
    |  cghi TMPR1, 1			// (> FF_C) Calling a fast function?
    |  jh >5
    |4:
    |  ins_callt
    |
    |5:  // Tailcall to a fast function.
    |  tmll PC, FRAME_TYPE		// Lua frame below?
    |  jne <4
    |  llgc RA, PC_RA
    |  lcgr RA, RA
    |  sllg RA, RA, 3(r0)
    |  lg LFUNC:KBASE, -32(RA, BASE)	// Need to prepare KBASE.
    |  cleartp LFUNC:KBASE
    |  lg KBASE, LFUNC:KBASE->pc
    |  lg KBASE, (PC2PROTO(k))(KBASE)
    |  j <4
    |
    |7:  // Tailcall from a vararg function.
    |  aghi PC, -FRAME_VARG
    |  tmll PC, FRAME_TYPEP
    |  jne >8				// Vararg frame below?
    |  sgr BASE, PC			// Need to relocate BASE/KBASE down.
    |  lgr KBASE, BASE
    |  lg PC, -8(BASE)
    |  j <1
    |8:
    |  aghi PC, FRAME_VARG
    |  j <1
    break;

  case BC_ITERC:
    |  stg r0, 0(r0)
    |  stg r0, 0(r0)
    break;
  case BC_ITERN:
    |  stg r0, 0(r0)
    |  stg r0, 0(r0)
    break;
  case BC_ISNEXT:
    |  stg r0, 0(r0)
    |  stg r0, 0(r0)
    break;
  case BC_VARG:
    |  stg r0, 0(r0)
    |  stg r0, 0(r0)
    break;
  case BC_RETM:
    |  stg r0, 0(r0) // not implemented
    |  stg r0, 0(r0)
    break;

  case BC_RET: case BC_RET0: case BC_RET1:
    |  ins_AD	// RA = results, RD = nresults+1
    if (op != BC_RET0) {
      |  sllg RA, RA, 3(r0)
    }
    |1:
    |  lg PC, -8(BASE)
    |  stg RD, SAVE_MULTRES		// Save nresults+1.
    |  tmll PC, FRAME_TYPE		// Check frame type marker.
    |  jne >7				// Not returning to a fixarg Lua func?
    switch (op) {
    case BC_RET:
      |->BC_RET_Z:
      |  lgr KBASE, BASE		// Use KBASE for result move.
      |  aghi RD, -1
      |  je >3
      |2:  // Move results down.
      |  lg RB, 0(KBASE, RA)
      |  stg RB, -16(KBASE)
      |  la KBASE, 8(KBASE)
      |  // TODO: replace with brctg RD, <2 once supported.
      |  aghi RD, -1
      |  jne <2
      |3:
      |  lg RD, SAVE_MULTRES		// Note: MULTRES may be >255.
      |  llgc RB, PC_RB
      |5:
      |  cgr RB, RD			// More results expected?
      |  jh >6
      break;
    case BC_RET1:
      |  lg RB, 0(BASE, RA)
      |  stg RB, -16(BASE)
      /* fallthrough */
    case BC_RET0:
      |5:
      |  llgc TMPR1, PC_RB
      |  cgr TMPR1, RD
      |  jh >6
    default:
      break;
    }
    |  llgc RA, PC_RA
    |  lcgr RA, RA
    |  sllg RA, RA, 3(r0)
    |  lay BASE, -16(RA, BASE)		// base = base - (RA+2)*8
    |  lg LFUNC:KBASE, -16(BASE)
    |  cleartp LFUNC:KBASE
    |  lg KBASE, LFUNC:KBASE->pc
    |  lg KBASE, PC2PROTO(k)(KBASE)
    |  ins_next
    |
    |6:  // Fill up results with nil.
    |  lghi TMPR1, LJ_TNIL
    if (op == BC_RET) {
      |  stg TMPR1, -16(KBASE)		// Note: relies on shifted base.
      |  la KBASE, 8(KBASE)
    } else {
      |  sllg RC, RD, 3(r0) 		// RC used as temp.
      |  stg TMPR1, -24(RC, BASE)
    }
    |  la RD, 1(RD)
    |  j <5
    |
    |7:  // Non-standard return case.
    |  lay RB, -FRAME_VARG(PC)
    |  tmll RB, FRAME_TYPEP
    |  jne ->vm_return
    |  // Return from vararg function: relocate BASE down and RA up.
    |  sgr BASE, RB
    if (op != BC_RET0) {
      |  agr RA, RB
    }
    |  j <1
    break;

  /* -- Loops and branches ------------------------------------------------ */

  |.define FOR_IDX,  0(RA)
  |.define FOR_STOP, 8(RA)
  |.define FOR_STEP, 16(RA)
  |.define FOR_EXT,  24(RA)

  case BC_FORL:
    |  stg r0, 0(r0)
    |  stg r0, 0(r0)
    break;

  case BC_JFORI:
  case BC_JFORL:
#if !LJ_HASJIT
    break;
#endif
  case BC_FORI:
  case BC_IFORL:
    vk = (op == BC_IFORL || op == BC_JFORL);
    |  ins_AJ	// RA = base, RD = target (after end of loop or start of loop)
    |  sllg RA, RA, 3(r0)
    |  la RA, 0(RA, BASE)
    |  lg RB, FOR_IDX
    |  checkint RB, >9
    |  lg TMPR1, FOR_STOP
    if (!vk) {
      |  checkint TMPR1, ->vmeta_for
      |  lg ITYPE, FOR_STEP
      |  chi ITYPE, 0; jl >5
      |  srag ITYPE, ITYPE, 47(r0)
      |  cghi ITYPE, LJ_TISNUM; jne ->vmeta_for
    } else {
#ifdef LUA_USE_ASSERT
      |  // lg TMPR1, FOR_STOP
      |  checkinttp TMPR1, ->assert_bad_for_arg_type
      |  lg TMPR2, FOR_STEP
      |  checkinttp TMPR2, ->assert_bad_for_arg_type
#endif
      |  lg ITYPE, FOR_STEP
      |  chi ITYPE, 0; jl >5
      |  ar RB, ITYPE; jo >1
      |  setint RB
      |  stg RB, FOR_IDX
    }
    |  cr RB, TMPR1
    |  stg RB, FOR_EXT
    if (op == BC_FORI) {
      |  jle >7
      |1:
      |6:
      |  branchPC RD
    } else if (op == BC_JFORI) {
      |  branchPC RD
      |  llgh RD, PC_RD
      |  jle =>BC_JLOOP
      |1:
      |6:
    } else if (op == BC_IFORL) {
      |  jh >7
      |6:
      |  branchPC RD
      |1:
    } else {
      |  jle =>BC_JLOOP
      |1:
      |6:
    }
    |7:
    |  ins_next
    |
    |5:  // Invert check for negative step.
    if (!vk) {
      |  srag ITYPE, ITYPE, 47(r0)
      |  cghi ITYPE, LJ_TISNUM; jne ->vmeta_for
    } else {
      |  ar RB, ITYPE; jo <1
      |  setint RB
      |  stg RB, FOR_IDX
    }
    |  cr RB, TMPR1
    |  stg RB, FOR_EXT
    if (op == BC_FORI) {
      |  jhe <7
    } else if (op == BC_JFORI) {
      |  branchPC RD
      |  llgh RD, PC_RD
      |  jhe =>BC_JLOOP
    } else if (op == BC_IFORL) {
      |  jl <7
    } else {
      |  jhe =>BC_JLOOP
    }
    |  j <6
    |9:  // Fallback to FP variant.
    if (!vk) {
      |  jhe ->vmeta_for
    }
    if (!vk) {
      |  lg TMPR2, FOR_STOP
      |  checknumtp TMPR2, ->vmeta_for
    } else {
#ifdef LUA_USE_ASSERT
      |  lg TMPR2, FOR_STOP
      |  checknumtp TMPR2, ->assert_bad_for_arg_type
      |  lg TMPR2, FOR_STEP
      |  checknumtp TMPR2, ->assert_bad_for_arg_type
#endif
    }
    |  lg RB, FOR_STEP
    if (!vk) {
      |  checknum RB, ->vmeta_for
    }
    |  ld f0, FOR_IDX
    |  ld f1, FOR_STOP
    if (vk) {
      |  adb f0, FOR_STEP
      |  std f0, FOR_IDX
    }
    |  cghi RB, 0; jl >3
    |  cdbr f1, f0
    |1:
    |  std f0, FOR_EXT
    if (op == BC_FORI) {
      |  jnl <7
    } else if (op == BC_JFORI) {
      |  branchPC RD
      |  llgh RD, PC_RD
      |  jnl =>BC_JLOOP
    } else if (op == BC_IFORL) {
      |  jl <7
    } else {
      |  jnl =>BC_JLOOP
    }
    |  j <6
    |
    |3:  // Invert comparison if step is negative.
    |  cdbr f0, f1
    |  j <1
    break;

  case BC_ITERL:
    |  stg r0, 0(r0)
    |  stg r0, 0(r0)
    break;
  case BC_JITERL:
    |  stg r0, 0(r0)
    |  stg r0, 0(r0)
    break;
  case BC_IITERL:
    |  stg r0, 0(r0)
    |  stg r0, 0(r0)
    break;
  case BC_LOOP:
    |  stg r0, 0(r0)
    |  stg r0, 0(r0)
    break;
  case BC_ILOOP:
    |  stg r0, 0(r0)
    |  stg r0, 0(r0)
    break;
  case BC_JLOOP:
    |  stg r0, 0(r0)
    |  stg r0, 0(r0)
    break;

  case BC_JMP:
    |  ins_AJ	// RA = unused, RD = target
    |  branchPC RD
    |  ins_next
    break;

  /* -- Function headers -------------------------------------------------- */

   /*
   ** Reminder: A function may be called with func/args above L->maxstack,
   ** i.e. occupying EXTRA_STACK slots. And vmeta_call may add one extra slot,
   ** too. This means all FUNC* ops (including fast functions) must check
   ** for stack overflow _before_ adding more slots!
   */

  case BC_FUNCF:
    |.if JIT
    |  stg r0, 0(r0)
    |.endif
  case BC_FUNCV:  /* NYI: compiled vararg functions. */
    | // Fall through. Assumes BC_IFUNCF/BC_IFUNCV follow and ins_AD is a no-op.
    break;

  case BC_JFUNCF:
#if !LJ_HASJIT
    break;
#endif
  case BC_IFUNCF:
    |  ins_AD  // BASE = new base, RA = framesize, RD = nargs+1
    |  lg KBASE, (PC2PROTO(k)-4)(PC)
    |  lg L:RB, SAVE_L
    |  sllg RA, RA, 3(r0)
    |  la RA, 0(RA, BASE)		// Top of frame.
    |  clg RA, L:RB->maxstack
    |  jh ->vm_growstack_f
    |  llgc RA, (PC2PROTO(numparams)-4)(PC)
    |  clgr NARGS:RD, RA		// Check for missing parameters.
    |  jle >3
    |2:
    if (op == BC_JFUNCF) {
      |  llgh RD, PC_RD
      |  j =>BC_JLOOP
    } else {
      |  ins_next
    }
    |
    |3:  // Clear missing parameters.
    |  // TODO: optimize this. Some of this can be hoisted.
    |  sllg TMPR1, NARGS:RD, 3(r0)
    |  lghi TMPR2, LJ_TNIL
    |  stg TMPR2, -8(TMPR1, BASE)
    |  la RD, 1(RD)
    |  clgr RD, RA
    |  jle <3
    |  j <2
    break;

  case BC_JFUNCV:
#if !LJ_HASJIT
    break;
#endif
    | stg r0, 0(r0)  // NYI: compiled vararg functions
    break;           /* NYI: compiled vararg functions. */

  case BC_IFUNCV:
    |  ins_AD  // BASE = new base, RA = framesize, RD = nargs+1
    |  sllg TMPR1, NARGS:RD, 3(r0)
    |  la RB, (FRAME_VARG+8)(TMPR1)
    |  la RD, 8(TMPR1, BASE)
    |  lg LFUNC:KBASE, -16(BASE)
    |  stg RB, -8(RD)			// Store delta + FRAME_VARG.
    |  stg LFUNC:KBASE, -16(RD)		// Store copy of LFUNC.
    |  lg L:RB, SAVE_L
    |  sllg RA, RA, 3(r0)
    |  la RA, 0(RA, RD)
    |  cg RA, L:RB->maxstack
    |  jh ->vm_growstack_v		// Need to grow stack.
    |  lgr RA, BASE
    |  lgr BASE, RD
    |  llgc RB, (PC2PROTO(numparams)-4)(PC)
    |  cghi RB, 0
    |  je >2
    |  aghi RA, 8
    |  lghi TMPR1, LJ_TNIL
    |1:  // Copy fixarg slots up to new frame.
    |  la RA, 8(RA)
    |  cgr RA, BASE
    |  jnl >3				// Less args than parameters?
    |  lg KBASE, -16(RA)
    |  stg KBASE, 0(RD)
    |  la RD, 8(RD)
    |  stg TMPR1, -16(RA)	// Clear old fixarg slot (help the GC).
    |  aghi RB, -1
    |  jne <1
    |  // TODO: brctg instead of decrement/branch
    |2:
    if (op == BC_JFUNCV) {
      |  llgh RD, PC_RD
      |  j =>BC_JLOOP
    } else {
      |  lg KBASE, (PC2PROTO(k)-4)(PC)
      |  ins_next
    }
    |
    |3:  // Clear missing parameters.
    |  stg TMPR1, 0(RD)			// TMPR1=LJ_TNIL (-1) here.
    |  la RD, 8(RD)
    |  aghi RB, -1
    |  jne <3
    |  // TODO: brctg instead of decrement/branch
    |  j <2
    break;

  case BC_FUNCC:
  case BC_FUNCCW:
    |  ins_AD  // BASE = new base, RD = nargs+1
    |  lg CFUNC:RB, -16(BASE)
    |  cleartp CFUNC:RB
    |  lg KBASE, CFUNC:RB->f
    |  lg L:RB, SAVE_L
    |  sllg RD, NARGS:RD, 3(r0)
    |  lay RD, -8(RD,BASE)
    |  stg BASE, L:RB->base
    |  lay RA, (8*LUA_MINSTACK)(RD)
    |  cg RA, L:RB->maxstack
    |  stg RD, L:RB->top
    |  lgr CARG1, L:RB			// Caveat: CARG1 may be RA.
    if (op != BC_FUNCC) {
      |  lgr CARG2, KBASE
    }
    |  jh ->vm_growstack_c		// Need to grow stack.
    |  set_vmstate C
    if (op == BC_FUNCC) {
      |  basr r14, KBASE		// (lua_State *L)
    } else {
      |  // (lua_State *L, lua_CFunction f)
      |  lg TMPR1, (DISPATCH_GL(wrapf))(DISPATCH)
      |  basr r14, TMPR1 // TODO: TMPR1==r14, is this ok?
    }
    |  // nresults returned in r2 (CRET1).
    |  lgr RD, CRET1
    |  lg BASE, L:RB->base
    |  stg L:RB, (DISPATCH_GL(cur_L))(DISPATCH)
    |  set_vmstate INTERP
    |  sllg TMPR1, RD, 3(r0)
    |  la RA, 0(TMPR1, BASE)
    |  lcgr RA, RA
    |  ag RA, L:RB->top			// RA = (L->top-(L->base+nresults))*8
    |  lg PC, -8(BASE)			// Fetch PC of caller.
    |  // BUG: PC seems to be -1 here sometimes. Not yet sure why.
    |  j ->vm_returnc
    break;

  /* ---------------------------------------------------------------------- */

  default:
    fprintf(stderr, "Error: undefined opcode BC_%s\n", bc_names[op]);
    exit(2);
    break;
  }
}

static int build_backend(BuildCtx *ctx)
{
  int op;
  dasm_growpc(Dst, BC__MAX);
  build_subroutines(ctx);
  |.code_op
  for (op = 0; op < BC__MAX; op++)
    build_ins(ctx, (BCOp)op, op);
  return BC__MAX;
}

/* Emit pseudo frame-info for all assembler functions. */
static void emit_asm_debug(BuildCtx *ctx)
{
}