forked from mia/Aegisub
467 lines
12 KiB
C
467 lines
12 KiB
C
/*
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** x86/x64 instruction emitter.
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** Copyright (C) 2005-2017 Mike Pall. See Copyright Notice in luajit.h
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*/
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/* -- Emit basic instructions --------------------------------------------- */
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#define MODRM(mode, r1, r2) ((MCode)((mode)+(((r1)&7)<<3)+((r2)&7)))
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#if LJ_64
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#define REXRB(p, rr, rb) \
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{ MCode rex = 0x40 + (((rr)>>1)&4) + (((rb)>>3)&1); \
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if (rex != 0x40) *--(p) = rex; }
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#define FORCE_REX 0x200
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#define REX_64 (FORCE_REX|0x080000)
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#else
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#define REXRB(p, rr, rb) ((void)0)
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#define FORCE_REX 0
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#define REX_64 0
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#endif
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#define emit_i8(as, i) (*--as->mcp = (MCode)(i))
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#define emit_i32(as, i) (*(int32_t *)(as->mcp-4) = (i), as->mcp -= 4)
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#define emit_u32(as, u) (*(uint32_t *)(as->mcp-4) = (u), as->mcp -= 4)
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#define emit_x87op(as, xo) \
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(*(uint16_t *)(as->mcp-2) = (uint16_t)(xo), as->mcp -= 2)
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/* op */
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static LJ_AINLINE MCode *emit_op(x86Op xo, Reg rr, Reg rb, Reg rx,
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MCode *p, int delta)
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{
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int n = (int8_t)xo;
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#if defined(__GNUC__)
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if (__builtin_constant_p(xo) && n == -2)
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p[delta-2] = (MCode)(xo >> 24);
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else if (__builtin_constant_p(xo) && n == -3)
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*(uint16_t *)(p+delta-3) = (uint16_t)(xo >> 16);
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else
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#endif
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*(uint32_t *)(p+delta-5) = (uint32_t)xo;
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p += n + delta;
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#if LJ_64
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{
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uint32_t rex = 0x40 + ((rr>>1)&(4+(FORCE_REX>>1)))+((rx>>2)&2)+((rb>>3)&1);
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if (rex != 0x40) {
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rex |= (rr >> 16);
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if (n == -4) { *p = (MCode)rex; rex = (MCode)(xo >> 8); }
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else if ((xo & 0xffffff) == 0x6600fd) { *p = (MCode)rex; rex = 0x66; }
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*--p = (MCode)rex;
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}
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}
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#else
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UNUSED(rr); UNUSED(rb); UNUSED(rx);
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#endif
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return p;
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}
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/* op + modrm */
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#define emit_opm(xo, mode, rr, rb, p, delta) \
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(p[(delta)-1] = MODRM((mode), (rr), (rb)), \
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emit_op((xo), (rr), (rb), 0, (p), (delta)))
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/* op + modrm + sib */
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#define emit_opmx(xo, mode, scale, rr, rb, rx, p) \
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(p[-1] = MODRM((scale), (rx), (rb)), \
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p[-2] = MODRM((mode), (rr), RID_ESP), \
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emit_op((xo), (rr), (rb), (rx), (p), -1))
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/* op r1, r2 */
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static void emit_rr(ASMState *as, x86Op xo, Reg r1, Reg r2)
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{
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MCode *p = as->mcp;
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as->mcp = emit_opm(xo, XM_REG, r1, r2, p, 0);
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}
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#if LJ_64 && defined(LUA_USE_ASSERT)
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/* [addr] is sign-extended in x64 and must be in lower 2G (not 4G). */
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static int32_t ptr2addr(const void *p)
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{
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lua_assert((uintptr_t)p < (uintptr_t)0x80000000);
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return i32ptr(p);
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}
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#else
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#define ptr2addr(p) (i32ptr((p)))
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#endif
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/* op r, [addr] */
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static void emit_rma(ASMState *as, x86Op xo, Reg rr, const void *addr)
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{
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MCode *p = as->mcp;
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*(int32_t *)(p-4) = ptr2addr(addr);
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#if LJ_64
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p[-5] = MODRM(XM_SCALE1, RID_ESP, RID_EBP);
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as->mcp = emit_opm(xo, XM_OFS0, rr, RID_ESP, p, -5);
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#else
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as->mcp = emit_opm(xo, XM_OFS0, rr, RID_EBP, p, -4);
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#endif
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}
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/* op r, [base+ofs] */
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static void emit_rmro(ASMState *as, x86Op xo, Reg rr, Reg rb, int32_t ofs)
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{
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MCode *p = as->mcp;
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x86Mode mode;
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if (ra_hasreg(rb)) {
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if (ofs == 0 && (rb&7) != RID_EBP) {
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mode = XM_OFS0;
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} else if (checki8(ofs)) {
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*--p = (MCode)ofs;
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mode = XM_OFS8;
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} else {
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p -= 4;
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*(int32_t *)p = ofs;
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mode = XM_OFS32;
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}
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if ((rb&7) == RID_ESP)
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*--p = MODRM(XM_SCALE1, RID_ESP, RID_ESP);
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} else {
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*(int32_t *)(p-4) = ofs;
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#if LJ_64
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p[-5] = MODRM(XM_SCALE1, RID_ESP, RID_EBP);
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p -= 5;
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rb = RID_ESP;
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#else
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p -= 4;
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rb = RID_EBP;
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#endif
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mode = XM_OFS0;
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}
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as->mcp = emit_opm(xo, mode, rr, rb, p, 0);
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}
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/* op r, [base+idx*scale+ofs] */
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static void emit_rmrxo(ASMState *as, x86Op xo, Reg rr, Reg rb, Reg rx,
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x86Mode scale, int32_t ofs)
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{
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MCode *p = as->mcp;
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x86Mode mode;
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if (ofs == 0 && (rb&7) != RID_EBP) {
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mode = XM_OFS0;
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} else if (checki8(ofs)) {
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mode = XM_OFS8;
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*--p = (MCode)ofs;
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} else {
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mode = XM_OFS32;
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p -= 4;
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*(int32_t *)p = ofs;
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}
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as->mcp = emit_opmx(xo, mode, scale, rr, rb, rx, p);
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}
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/* op r, i */
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static void emit_gri(ASMState *as, x86Group xg, Reg rb, int32_t i)
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{
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MCode *p = as->mcp;
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x86Op xo;
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if (checki8(i)) {
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*--p = (MCode)i;
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xo = XG_TOXOi8(xg);
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} else {
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p -= 4;
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*(int32_t *)p = i;
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xo = XG_TOXOi(xg);
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}
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as->mcp = emit_opm(xo, XM_REG, (Reg)(xg & 7) | (rb & REX_64), rb, p, 0);
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}
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/* op [base+ofs], i */
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static void emit_gmroi(ASMState *as, x86Group xg, Reg rb, int32_t ofs,
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int32_t i)
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{
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x86Op xo;
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if (checki8(i)) {
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emit_i8(as, i);
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xo = XG_TOXOi8(xg);
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} else {
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emit_i32(as, i);
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xo = XG_TOXOi(xg);
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}
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emit_rmro(as, xo, (Reg)(xg & 7), rb, ofs);
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}
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#define emit_shifti(as, xg, r, i) \
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(emit_i8(as, (i)), emit_rr(as, XO_SHIFTi, (Reg)(xg), (r)))
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/* op r, rm/mrm */
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static void emit_mrm(ASMState *as, x86Op xo, Reg rr, Reg rb)
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{
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MCode *p = as->mcp;
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x86Mode mode = XM_REG;
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if (rb == RID_MRM) {
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rb = as->mrm.base;
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if (rb == RID_NONE) {
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rb = RID_EBP;
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mode = XM_OFS0;
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p -= 4;
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*(int32_t *)p = as->mrm.ofs;
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if (as->mrm.idx != RID_NONE)
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goto mrmidx;
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#if LJ_64
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*--p = MODRM(XM_SCALE1, RID_ESP, RID_EBP);
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rb = RID_ESP;
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#endif
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} else {
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if (as->mrm.ofs == 0 && (rb&7) != RID_EBP) {
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mode = XM_OFS0;
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} else if (checki8(as->mrm.ofs)) {
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*--p = (MCode)as->mrm.ofs;
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mode = XM_OFS8;
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} else {
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p -= 4;
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*(int32_t *)p = as->mrm.ofs;
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mode = XM_OFS32;
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}
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if (as->mrm.idx != RID_NONE) {
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mrmidx:
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as->mcp = emit_opmx(xo, mode, as->mrm.scale, rr, rb, as->mrm.idx, p);
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return;
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}
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if ((rb&7) == RID_ESP)
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*--p = MODRM(XM_SCALE1, RID_ESP, RID_ESP);
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}
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}
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as->mcp = emit_opm(xo, mode, rr, rb, p, 0);
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}
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/* op rm/mrm, i */
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static void emit_gmrmi(ASMState *as, x86Group xg, Reg rb, int32_t i)
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{
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x86Op xo;
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if (checki8(i)) {
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emit_i8(as, i);
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xo = XG_TOXOi8(xg);
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} else {
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emit_i32(as, i);
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xo = XG_TOXOi(xg);
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}
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emit_mrm(as, xo, (Reg)(xg & 7) | (rb & REX_64), (rb & ~REX_64));
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}
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/* -- Emit loads/stores --------------------------------------------------- */
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/* Instruction selection for XMM moves. */
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#define XMM_MOVRR(as) ((as->flags & JIT_F_SPLIT_XMM) ? XO_MOVSD : XO_MOVAPS)
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#define XMM_MOVRM(as) ((as->flags & JIT_F_SPLIT_XMM) ? XO_MOVLPD : XO_MOVSD)
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/* mov [base+ofs], i */
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static void emit_movmroi(ASMState *as, Reg base, int32_t ofs, int32_t i)
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{
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emit_i32(as, i);
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emit_rmro(as, XO_MOVmi, 0, base, ofs);
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}
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/* mov [base+ofs], r */
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#define emit_movtomro(as, r, base, ofs) \
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emit_rmro(as, XO_MOVto, (r), (base), (ofs))
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/* Get/set global_State fields. */
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#define emit_opgl(as, xo, r, field) \
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emit_rma(as, (xo), (r), (void *)&J2G(as->J)->field)
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#define emit_getgl(as, r, field) emit_opgl(as, XO_MOV, (r), field)
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#define emit_setgl(as, r, field) emit_opgl(as, XO_MOVto, (r), field)
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#define emit_setvmstate(as, i) \
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(emit_i32(as, i), emit_opgl(as, XO_MOVmi, 0, vmstate))
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/* mov r, i / xor r, r */
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static void emit_loadi(ASMState *as, Reg r, int32_t i)
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{
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/* XOR r,r is shorter, but modifies the flags. This is bad for HIOP. */
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if (i == 0 && !(LJ_32 && (IR(as->curins)->o == IR_HIOP ||
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(as->curins+1 < as->T->nins &&
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IR(as->curins+1)->o == IR_HIOP)))) {
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emit_rr(as, XO_ARITH(XOg_XOR), r, r);
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} else {
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MCode *p = as->mcp;
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*(int32_t *)(p-4) = i;
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p[-5] = (MCode)(XI_MOVri+(r&7));
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p -= 5;
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REXRB(p, 0, r);
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as->mcp = p;
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}
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}
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/* mov r, addr */
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#define emit_loada(as, r, addr) \
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emit_loadi(as, (r), ptr2addr((addr)))
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#if LJ_64
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/* mov r, imm64 or shorter 32 bit extended load. */
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static void emit_loadu64(ASMState *as, Reg r, uint64_t u64)
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{
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if (checku32(u64)) { /* 32 bit load clears upper 32 bits. */
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emit_loadi(as, r, (int32_t)u64);
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} else if (checki32((int64_t)u64)) { /* Sign-extended 32 bit load. */
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MCode *p = as->mcp;
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*(int32_t *)(p-4) = (int32_t)u64;
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as->mcp = emit_opm(XO_MOVmi, XM_REG, REX_64, r, p, -4);
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} else { /* Full-size 64 bit load. */
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MCode *p = as->mcp;
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*(uint64_t *)(p-8) = u64;
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p[-9] = (MCode)(XI_MOVri+(r&7));
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p[-10] = 0x48 + ((r>>3)&1);
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p -= 10;
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as->mcp = p;
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}
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}
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#endif
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/* movsd r, [&tv->n] / xorps r, r */
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static void emit_loadn(ASMState *as, Reg r, cTValue *tv)
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{
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if (tvispzero(tv)) /* Use xor only for +0. */
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emit_rr(as, XO_XORPS, r, r);
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else
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emit_rma(as, XMM_MOVRM(as), r, &tv->n);
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}
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/* -- Emit control-flow instructions -------------------------------------- */
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/* Label for short jumps. */
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typedef MCode *MCLabel;
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#if LJ_32 && LJ_HASFFI
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/* jmp short target */
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static void emit_sjmp(ASMState *as, MCLabel target)
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{
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MCode *p = as->mcp;
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ptrdiff_t delta = target - p;
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lua_assert(delta == (int8_t)delta);
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p[-1] = (MCode)(int8_t)delta;
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p[-2] = XI_JMPs;
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as->mcp = p - 2;
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}
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#endif
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/* jcc short target */
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static void emit_sjcc(ASMState *as, int cc, MCLabel target)
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{
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MCode *p = as->mcp;
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ptrdiff_t delta = target - p;
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lua_assert(delta == (int8_t)delta);
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p[-1] = (MCode)(int8_t)delta;
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p[-2] = (MCode)(XI_JCCs+(cc&15));
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as->mcp = p - 2;
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}
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/* jcc short (pending target) */
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static MCLabel emit_sjcc_label(ASMState *as, int cc)
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{
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MCode *p = as->mcp;
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p[-1] = 0;
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p[-2] = (MCode)(XI_JCCs+(cc&15));
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as->mcp = p - 2;
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return p;
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}
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/* Fixup jcc short target. */
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static void emit_sfixup(ASMState *as, MCLabel source)
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{
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source[-1] = (MCode)(as->mcp-source);
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}
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/* Return label pointing to current PC. */
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#define emit_label(as) ((as)->mcp)
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/* Compute relative 32 bit offset for jump and call instructions. */
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static LJ_AINLINE int32_t jmprel(MCode *p, MCode *target)
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{
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ptrdiff_t delta = target - p;
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lua_assert(delta == (int32_t)delta);
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return (int32_t)delta;
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}
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/* jcc target */
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static void emit_jcc(ASMState *as, int cc, MCode *target)
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{
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MCode *p = as->mcp;
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*(int32_t *)(p-4) = jmprel(p, target);
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p[-5] = (MCode)(XI_JCCn+(cc&15));
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p[-6] = 0x0f;
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as->mcp = p - 6;
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}
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/* jmp target */
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static void emit_jmp(ASMState *as, MCode *target)
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{
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MCode *p = as->mcp;
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*(int32_t *)(p-4) = jmprel(p, target);
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p[-5] = XI_JMP;
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as->mcp = p - 5;
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}
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/* call target */
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static void emit_call_(ASMState *as, MCode *target)
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{
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MCode *p = as->mcp;
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#if LJ_64
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if (target-p != (int32_t)(target-p)) {
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/* Assumes RID_RET is never an argument to calls and always clobbered. */
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emit_rr(as, XO_GROUP5, XOg_CALL, RID_RET);
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emit_loadu64(as, RID_RET, (uint64_t)target);
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return;
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}
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#endif
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*(int32_t *)(p-4) = jmprel(p, target);
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p[-5] = XI_CALL;
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as->mcp = p - 5;
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}
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#define emit_call(as, f) emit_call_(as, (MCode *)(void *)(f))
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/* -- Emit generic operations --------------------------------------------- */
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/* Use 64 bit operations to handle 64 bit IR types. */
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#if LJ_64
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#define REX_64IR(ir, r) ((r) + (irt_is64((ir)->t) ? REX_64 : 0))
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#else
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#define REX_64IR(ir, r) (r)
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#endif
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/* Generic move between two regs. */
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static void emit_movrr(ASMState *as, IRIns *ir, Reg dst, Reg src)
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{
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UNUSED(ir);
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if (dst < RID_MAX_GPR)
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emit_rr(as, XO_MOV, REX_64IR(ir, dst), src);
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else
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emit_rr(as, XMM_MOVRR(as), dst, src);
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}
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/* Generic load of register from stack slot. */
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static void emit_spload(ASMState *as, IRIns *ir, Reg r, int32_t ofs)
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{
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if (r < RID_MAX_GPR)
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emit_rmro(as, XO_MOV, REX_64IR(ir, r), RID_ESP, ofs);
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else
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emit_rmro(as, irt_isnum(ir->t) ? XMM_MOVRM(as) : XO_MOVSS, r, RID_ESP, ofs);
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}
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/* Generic store of register to stack slot. */
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static void emit_spstore(ASMState *as, IRIns *ir, Reg r, int32_t ofs)
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{
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|
if (r < RID_MAX_GPR)
|
|
emit_rmro(as, XO_MOVto, REX_64IR(ir, r), RID_ESP, ofs);
|
|
else
|
|
emit_rmro(as, irt_isnum(ir->t) ? XO_MOVSDto : XO_MOVSSto, r, RID_ESP, ofs);
|
|
}
|
|
|
|
/* Add offset to pointer. */
|
|
static void emit_addptr(ASMState *as, Reg r, int32_t ofs)
|
|
{
|
|
if (ofs) {
|
|
if ((as->flags & JIT_F_LEA_AGU))
|
|
emit_rmro(as, XO_LEA, r, r, ofs);
|
|
else
|
|
emit_gri(as, XG_ARITHi(XOg_ADD), r, ofs);
|
|
}
|
|
}
|
|
|
|
#define emit_spsub(as, ofs) emit_addptr(as, RID_ESP|REX_64, -(ofs))
|
|
|
|
/* Prefer rematerialization of BASE/L from global_State over spills. */
|
|
#define emit_canremat(ref) ((ref) <= REF_BASE)
|
|
|