From 01be7f5748a116b06bc5f3bdf2ead5b29668e818 Mon Sep 17 00:00:00 2001 From: Peter Cawley Date: Fri, 25 Dec 2015 15:44:47 +0000 Subject: [PATCH] DynASM/x64: Full VREG support. --- dynasm/dasm_x86.h | 31 ++++++++++--- dynasm/dasm_x86.lua | 109 +++++++++++++++++++++++++++++++------------- 2 files changed, 103 insertions(+), 37 deletions(-) diff --git a/dynasm/dasm_x86.h b/dynasm/dasm_x86.h index 175febe0..782c3192 100644 --- a/dynasm/dasm_x86.h +++ b/dynasm/dasm_x86.h @@ -170,7 +170,7 @@ void dasm_put(Dst_DECL, int start, ...) dasm_State *D = Dst_REF; dasm_ActList p = D->actionlist + start; dasm_Section *sec = D->section; - int pos = sec->pos, ofs = sec->ofs, mrm = 4; + int pos = sec->pos, ofs = sec->ofs, mrm = -1; int *b; if (pos >= sec->epos) { @@ -193,7 +193,7 @@ void dasm_put(Dst_DECL, int start, ...) b[pos++] = n; switch (action) { case DASM_DISP: - if (n == 0) { if ((mrm&7) == 4) mrm = p[-2]; if ((mrm&7) != 5) break; } + if (n == 0) { if (mrm < 0) mrm = p[-2]; if ((mrm&7) != 5) break; } case DASM_IMM_DB: if (((n+128)&-256) == 0) goto ob; case DASM_REL_A: /* Assumes ptrdiff_t is int. !x64 */ case DASM_IMM_D: ofs += 4; break; @@ -203,10 +203,17 @@ void dasm_put(Dst_DECL, int start, ...) case DASM_IMM_W: CK((n&-65536) == 0, RANGE_I); ofs += 2; break; case DASM_SPACE: p++; ofs += n; break; case DASM_SETLABEL: b[pos-2] = -0x40000000; break; /* Neg. label ofs. */ - case DASM_VREG: CK((n&-8) == 0 && (n != 4 || (*p&1) == 0), RANGE_VREG); - if (*p++ == 1 && *p == DASM_DISP) mrm = n; continue; + case DASM_VREG: CK((n&-16) == 0 && (n != 4 || (*p>>5) != 2), RANGE_VREG); + if (*p < 0x40 && p[1] == DASM_DISP) mrm = n; + if (*p < 0x20 && (n&7) == 4) ++ofs; + switch ((*p++>>3)&3) { + case 3: n |= b[pos-3]; + case 2: n |= b[pos-2]; + case 1: if(n <= 7) b[pos-1] |= 0x10, --ofs; + } + continue; } - mrm = 4; + mrm = -1; } else { int *pl, n; switch (action) { @@ -393,7 +400,19 @@ int dasm_encode(Dst_DECL, void *buffer) case DASM_IMM_W: dasmw(n); break; case DASM_VREG: { int t = *p++; - if (t >= 5) n <<= 4; else if (t >= 2) n <<= 3; + unsigned char* ex = cp - (t&7); + if ((n & 8) && (t < 0xa0)) { + if (*ex & 0x80) ex[1] ^= 0x20<<(t>>6); else *ex ^= 1<<(t>>6); + n &= 7; + } else if (n & 0x10) { + if (*ex & 0x80) *ex = 0xc5, ex[1] = (ex[1] & 0x80) | ex[2], ex += 2; + while (++ex < cp) ex[-1] = *ex; + if (mark) --mark; + --cp; n &= 7; + } + if (t >= 0xc0) n <<= 4; + else if (t >= 0x40) n <<= 3; + else if (n == 4 && t < 0x20) cp[-1] ^= n, *cp++ = 0x20; cp[-1] ^= n; break; } diff --git a/dynasm/dasm_x86.lua b/dynasm/dasm_x86.lua index 1fa80b55..0bf0b7fd 100644 --- a/dynasm/dasm_x86.lua +++ b/dynasm/dasm_x86.lua @@ -41,7 +41,7 @@ local action_names = { -- int arg, 1 buffer pos: "DISP", "IMM_S", "IMM_B", "IMM_W", "IMM_D", "IMM_WB", "IMM_DB", -- action arg (1 byte), int arg, 1 buffer pos (reg/num): - "VREG", "SPACE", -- !x64: VREG support NYI. + "VREG", "SPACE", -- ptrdiff_t arg, 1 buffer pos (address): !x64 "SETLABEL", "REL_A", -- action arg (1 byte) or int arg, 2 buffer pos (link, offset): @@ -83,6 +83,21 @@ local actargs = { 0 } -- Current number of section buffer positions for dasm_put(). local secpos = 1 +-- VREG kind encodings (pre-shifted by 5 bits) +local map_vreg = { + ["modrm.rm.m"] = 0x00, + ["modrm.rm.r"] = 0x20, + ["opcode"] = 0x20, + ["sib.base"] = 0x20, + ["sib.index"] = 0x40, + ["modrm.reg"] = 0x80, + ["vex.v"] = 0xa0, + ["imm.hi"] = 0xc0, +} + +-- Current number of VREG actions contributing to REX/VEX shrinkage. +local vreg_shrink_count = 0 + ------------------------------------------------------------------------------ -- Compute action numbers for action names. @@ -134,6 +149,21 @@ local function waction(action, a, num) if a or num then secpos = secpos + (num or 1) end end +-- Optionally add a VREG action. +local function wvreg(kind, vreg, psz, sk, defer) + if not vreg then return end + waction("VREG", vreg) + local b = assert(map_vreg[kind], "bad vreg kind `"..vreg.."'") + if b < (sk or 0) then + vreg_shrink_count = vreg_shrink_count + 1 + end + if not defer then + b = b + vreg_shrink_count * 8 + vreg_shrink_count = 0 + end + wputxb(b + (psz or 0)) +end + -- Add call to embedded DynASM C code. local function wcall(func, args) wline(format("dasm_%s(Dst, %s);", func, concat(args, ", ")), true) @@ -326,6 +356,7 @@ mkrmap("w", "Rw", {"ax", "cx", "dx", "bx", "sp", "bp", "si", "di"}) mkrmap("b", "Rb", {"al", "cl", "dl", "bl", "ah", "ch", "dh", "bh"}) map_reg_valid_index[map_archdef.esp] = false if x64 then map_reg_valid_index[map_archdef.rsp] = false end +if x64 then map_reg_needrex[map_archdef.Rb] = true end map_archdef["Ra"] = "@"..addrsize -- FP registers (internally tword sized, but use "f" as operand size). @@ -463,16 +494,24 @@ local function wputszarg(sz, n) end -- Put multi-byte opcode with operand-size dependent modifications. -local function wputop(sz, op, rex, vex) +local function wputop(sz, op, rex, vex, vregr, vregxb) + local psz, sk = 0 if vex then local tail if vex.m == 1 and band(rex, 11) == 0 then - wputb(0xc5) - tail = shl(bxor(band(rex, 4), 4), 5) - else + if x64 and vregxb then + sk = map_vreg["modrm.reg"] + else + wputb(0xc5) + tail = shl(bxor(band(rex, 4), 4), 5) + psz = 3 + end + end + if not tail then wputb(0xc4) wputb(shl(bxor(band(rex, 7), 7), 5) + vex.m) tail = shl(band(rex, 8), 4) + psz = 4 end local reg, vreg = 0, nil if vex.v then @@ -482,12 +521,18 @@ local function wputop(sz, op, rex, vex) end if sz == "y" or vex.l then tail = tail + 4 end wputb(tail + shl(bxor(reg, 15), 3) + vex.p) - if vreg then waction("VREG", vreg); wputxb(4) end + wvreg("vex.v", vreg) rex = 0 if op >= 256 then werror("bad vex opcode") end + else + if rex ~= 0 then + if not x64 then werror("bad operand size") end + elseif (vregr or vregxb) and x64 then + rex = 0x10 + sk = map_vreg["vex.v"] + end end local r - if rex ~= 0 and not x64 then werror("bad operand size") end if sz == "w" then wputb(102) end -- Needs >32 bit numbers, but only for crc32 eax, word [ebx] if op >= 4294967296 then r = op%4294967296 wputb((op-r)/4294967296) op = r end @@ -496,20 +541,20 @@ local function wputop(sz, op, rex, vex) if rex ~= 0 then local opc3 = band(op, 0xffff00) if opc3 == 0x0f3a00 or opc3 == 0x0f3800 then - wputb(64 + band(rex, 15)); rex = 0 + wputb(64 + band(rex, 15)); rex = 0; psz = 2 end end - wputb(shr(op, 16)); op = band(op, 0xffff) + wputb(shr(op, 16)); op = band(op, 0xffff); psz = psz + 1 end if op >= 256 then local b = shr(op, 8) - if b == 15 and rex ~= 0 then wputb(64 + band(rex, 15)); rex = 0 end - wputb(b) - op = band(op, 255) + if b == 15 and rex ~= 0 then wputb(64 + band(rex, 15)); rex = 0; psz = 2 end + wputb(b); op = band(op, 255); psz = psz + 1 end - if rex ~= 0 then wputb(64 + band(rex, 15)) end + if rex ~= 0 then wputb(64 + band(rex, 15)); psz = 2 end if sz == "b" then op = op - 1 end wputb(op) + return psz, sk end -- Put ModRM or SIB formatted byte. @@ -519,7 +564,7 @@ local function wputmodrm(m, s, rm, vs, vrm) end -- Put ModRM/SIB plus optional displacement. -local function wputmrmsib(t, imark, s, vsreg) +local function wputmrmsib(t, imark, s, vsreg, psz, sk) local vreg, vxreg local reg, xreg = t.reg, t.xreg if reg and reg < 0 then reg = 0; vreg = t.vreg end @@ -529,8 +574,8 @@ local function wputmrmsib(t, imark, s, vsreg) -- Register mode. if sub(t.mode, 1, 1) == "r" then wputmodrm(3, s, reg) - if vsreg then waction("VREG", vsreg); wputxb(2) end - if vreg then waction("VREG", vreg); wputxb(0) end + wvreg("modrm.reg", vsreg, psz+1, sk, vreg) + wvreg("modrm.rm.r", vreg, psz+1, sk) return end @@ -544,21 +589,22 @@ local function wputmrmsib(t, imark, s, vsreg) -- [xreg*xsc+disp] -> (0, s, esp) (xsc, xreg, ebp) wputmodrm(0, s, 4) if imark == "I" then waction("MARK") end - if vsreg then waction("VREG", vsreg); wputxb(2) end + wvreg("modrm.reg", vsreg, psz+1, sk, vxreg) wputmodrm(t.xsc, xreg, 5) - if vxreg then waction("VREG", vxreg); wputxb(3) end + wvreg("sib.index", vxreg, psz+2, sk) else -- Pure 32 bit displacement. if x64 and tdisp ~= "table" then wputmodrm(0, s, 4) -- [disp] -> (0, s, esp) (0, esp, ebp) + wvreg("modrm.reg", vsreg, psz+1, sk) if imark == "I" then waction("MARK") end wputmodrm(0, 4, 5) else riprel = x64 wputmodrm(0, s, 5) -- [disp|rip-label] -> (0, s, ebp) + wvreg("modrm.reg", vsreg, psz+1, sk) if imark == "I" then waction("MARK") end end - if vsreg then waction("VREG", vsreg); wputxb(2) end end if riprel then -- Emit rip-relative displacement. if match("UWSiI", imark) then @@ -586,16 +632,16 @@ local function wputmrmsib(t, imark, s, vsreg) if xreg or band(reg, 7) == 4 then wputmodrm(m or 2, s, 4) -- ModRM. if m == nil or imark == "I" then waction("MARK") end - if vsreg then waction("VREG", vsreg); wputxb(2) end + wvreg("modrm.reg", vsreg, psz+1, sk, vxreg or vreg) wputmodrm(t.xsc or 0, xreg or 4, reg) -- SIB. - if vxreg then waction("VREG", vxreg); wputxb(3) end - if vreg then waction("VREG", vreg); wputxb(1) end + wvreg("sib.index", vxreg, psz+2, sk, vreg) + wvreg("sib.base", vreg, psz+2, sk) else wputmodrm(m or 2, s, reg) -- ModRM. if (imark == "I" and (m == 1 or m == 2)) or (m == nil and (vsreg or vreg)) then waction("MARK") end - if vsreg then waction("VREG", vsreg); wputxb(2) end - if vreg then waction("VREG", vreg); wputxb(1) end + wvreg("modrm.reg", vsreg, psz+1, sk, vreg) + wvreg("modrm.rm.m", vreg, psz+1, sk) end -- Put displacement. @@ -1761,10 +1807,11 @@ local function dopattern(pat, args, sz, op, needrex) if t.xreg and t.xreg > 7 then rex = rex + 2 end if s > 7 then rex = rex + 4 end if needrex then rex = rex + 16 end - wputop(szov, opcode, rex, vex); opcode = nil + local psz, sk = wputop(szov, opcode, rex, vex, s < 0, t.vreg or t.vxreg) + opcode = nil local imark = sub(pat, -1) -- Force a mark (ugly). -- Put ModRM/SIB with regno/last digit as spare. - wputmrmsib(t, imark, s, addin and addin.vreg) + wputmrmsib(t, imark, s, addin and addin.vreg, psz, sk) addin = nil elseif map_vexarg[c] ~= nil then -- Encode using VEX prefix local b = band(opcode, 255); opcode = shr(opcode, 8) @@ -1791,8 +1838,8 @@ local function dopattern(pat, args, sz, op, needrex) if szov == "q" and rex == 0 then rex = rex + 8 end if needrex then rex = rex + 16 end if addin and addin.reg == -1 then - wputop(szov, opcode - 7, rex, vex) - waction("VREG", addin.vreg); wputxb(0) + local psz, sk = wputop(szov, opcode - 7, rex, vex, true) + wvreg("opcode", addin.vreg, psz, sk) else if addin and addin.reg > 7 then rex = rex + 1 end wputop(szov, opcode, rex, vex) @@ -1836,7 +1883,7 @@ local function dopattern(pat, args, sz, op, needrex) local reg = a.reg if reg < 0 then wputb(0) - waction("VREG", a.vreg); wputxb(5) + wvreg("imm.hi", a.vreg) else wputb(shl(reg, 4)) end @@ -1988,8 +2035,8 @@ if x64 then rex = a.reg > 7 and 9 or 8 end end - wputop(sz, opcode, rex) - if vreg then waction("VREG", vreg); wputxb(0) end + local psz, sk = wputop(sz, opcode, rex, nil, vreg) + wvreg("opcode", vreg, psz, sk) waction("IMM_D", format("(unsigned int)(%s)", op64)) waction("IMM_D", format("(unsigned int)((%s)>>32)", op64)) end