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* patch by J. Gareth Moreton: CMOV extensions: frame/stack pointer relative references are always valid, resolves #36675

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git-svn-id: trunk@44141 -
This commit is contained in:
florian 2020-02-09 17:39:50 +00:00
parent d750582581
commit 12d015a935
1 changed files with 36 additions and 11 deletions
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47
compiler/x86/aoptx86.pas
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@ -61,6 +61,15 @@ unit aoptx86;
except where the register is being written }
function ReplaceRegisterInInstruction(const p: taicpu; const AOldReg, ANewReg: TRegister): Boolean;
{ Returns true if the reference only refers to ESP or EBP (or their 64-bit equivalents),
or writes to a global symbol }
class function IsRefSafe(const ref: PReference): Boolean; static; inline;
{ Returns true if the given MOV instruction can be safely converted to CMOV }
class function CanBeCMOV(p : tai) : boolean; static;
function DeepMOVOpt(const p_mov: taicpu; const hp: taicpu): Boolean;
procedure DebugMsg(const s : string; p : tai);inline;
@ -1627,6 +1636,23 @@ unit aoptx86;
end;
class function TX86AsmOptimizer.IsRefSafe(const ref: PReference): Boolean; inline;
begin
Result :=
(ref^.index = NR_NO) and
(
{$ifdef x86_64}
(
(ref^.base = NR_RIP) and
(ref^.refaddr in [addr_pic, addr_pic_no_got])
) or
{$endif x86_64}
(ref^.base = NR_STACK_POINTER_REG) or
(ref^.base = current_procinfo.framepointer)
);
end;
function TX86AsmOptimizer.DeepMOVOpt(const p_mov: taicpu; const hp: taicpu): Boolean;
var
CurrentReg, ReplaceReg: TRegister;
@ -4638,7 +4664,7 @@ unit aoptx86;
end;
function CanBeCMOV(p : tai) : boolean;
class function TX86AsmOptimizer.CanBeCMOV(p : tai) : boolean;
begin
CanBeCMOV:=assigned(p) and
MatchInstruction(p,A_MOV,[S_W,S_L,S_Q]) and
@ -4648,16 +4674,15 @@ unit aoptx86;
or ((taicpu(p).oper[0]^.typ = top_ref) and
(taicpu(p).oper[0]^.ref^.refaddr = addr_no))
}
(MatchOpType(taicpu(p),top_reg,top_reg) or
{ allow references, but only pure symbols or got rel. addressing with RIP as based,
it is not expected that this can cause a seg. violation }
(MatchOpType(taicpu(p),top_ref,top_reg) and
(((taicpu(p).oper[0]^.ref^.base=NR_NO) and (taicpu(p).oper[0]^.ref^.refaddr=addr_no)){$ifdef x86_64} or
((taicpu(p).oper[0]^.ref^.base=NR_RIP) and (taicpu(p).oper[0]^.ref^.refaddr=addr_pic)){$endif x86_64}
) and
(taicpu(p).oper[0]^.ref^.index=NR_NO) and
(taicpu(p).oper[0]^.ref^.offset=0)
)
(taicpu(p).oper[1]^.typ = top_reg) and
(
(taicpu(p).oper[0]^.typ = top_reg) or
{ allow references, but only pure symbols or got rel. addressing with RIP as based,
it is not expected that this can cause a seg. violation }
(
(taicpu(p).oper[0]^.typ = top_ref) and
IsRefSafe(taicpu(p).oper[0]^.ref)
)
);
end;