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DynASM/x64: Allow "&expr" syntax in MRM to generate IP-relative code

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DynASM already allows usage of jump taget syntax in x86 MRM

| mov rax, [->1]

On x86_86 this leads to generatation of IP-realtive code. but for some reason  "&expr" jump target syntax is not supported.
The patch enables this syntax, so now we may write

| mov rcx, [&addr]

instead of

| mov64 rcx, &addr
| mov rcx, [rcx]
This commit is contained in:
Dmitry Stogov 2023-12-22 17:10:27 +03:00
parent 29b0b282f5
commit 35a36aa20b
1 changed files with 8 additions and 4 deletions
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12
dynasm/dasm_x86.lua
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@ -478,7 +478,7 @@ local function wputdarg(n)
wputb(band(shr(n, 16), 255)) wputb(band(shr(n, 16), 255))
wputb(shr(n, 24)) wputb(shr(n, 24))
elseif tn == "table" then elseif tn == "table" then
wputlabel("IMM_", n[1], 1) wputlabel("IMM_", n[2], 1)
else else
waction("IMM_D", n) waction("IMM_D", n)
end end
@ -627,7 +627,11 @@ local function wputmrmsib(t, imark, s, vsreg, psz, sk)
werror("NYI: rip-relative displacement followed by immediate") werror("NYI: rip-relative displacement followed by immediate")
end end
-- The previous byte in the action buffer cannot be 0xe9 or 0x80-0x8f. -- The previous byte in the action buffer cannot be 0xe9 or 0x80-0x8f.
wputlabel("REL_", disp[1], 2) if disp[1] == "iPJ" then
waction("REL_A", disp[2])
else
wputlabel("REL_", disp[2], 2)
end
else else
wputdarg(disp) wputdarg(disp)
end end
@ -744,9 +748,9 @@ local function dispexpr(expr)
return imm*map_opsizenum[ops] return imm*map_opsizenum[ops]
end end
local mode, iexpr = immexpr(dispt) local mode, iexpr = immexpr(dispt)
if mode == "iJ" then if mode == "iJ" or mode == "iPJ" then
if c == "-" then werror("cannot invert label reference") end if c == "-" then werror("cannot invert label reference") end
return { iexpr } return { mode, iexpr }
end end
return expr -- Need to return original signed expression. return expr -- Need to return original signed expression.
end end