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* x86: Revamped OptPass2Jcc CMOV code to shrink and reuse registers as much as possible

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This commit is contained in:
J. Gareth "Curious Kit" Moreton 2023-07-16 10:43:03 +01:00 committed by FPK
parent 2a83972db8
commit 6ffa258abb
1 changed files with 58 additions and 13 deletions
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71
compiler/x86/aoptx86.pas
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@ -11696,6 +11696,9 @@ unit aoptx86;
function TX86AsmOptimizer.OptPass2Jcc(var p : tai) : boolean; function TX86AsmOptimizer.OptPass2Jcc(var p : tai) : boolean;
const
subreg2opsize : array[tsubregister] of topsize =
(S_NO,S_B,S_B,S_W,S_L,S_Q,S_NO,S_NO,S_NO,S_NO,S_NO,S_NO,S_NO,S_NO,S_NO,S_NO,S_NO,S_NO,S_NO,S_NO,S_NO,S_NO,S_NO,S_NO);
var var
hp1,hp2: tai; hp1,hp2: tai;
carryadd_opcode : TAsmOp; carryadd_opcode : TAsmOp;
@ -11714,6 +11717,10 @@ unit aoptx86;
ConstRegs: array[0..MAX_CMOV_REGISTERS - 1] of TRegister; ConstRegs: array[0..MAX_CMOV_REGISTERS - 1] of TRegister;
ConstVals: array[0..MAX_CMOV_REGISTERS - 1] of TCGInt; ConstVals: array[0..MAX_CMOV_REGISTERS - 1] of TCGInt;
ConstSizes: array[0..MAX_CMOV_REGISTERS - 1] of TSubRegister; { May not match ConstRegs if one is shared over multiple CMOVs. }
ConstMovs: array[0..MAX_CMOV_REGISTERS - 1] of tai; { Location of initialisation instruction }
ConstWriteSizes: array[0..first_int_imreg - 1] of TSubRegister; { Largest size of register written. }
{ Tries to convert a mov const,%reg instruction into a CMOV by reserving a { Tries to convert a mov const,%reg instruction into a CMOV by reserving a
new register to store the constant } new register to store the constant }
@ -11750,10 +11757,10 @@ unit aoptx86;
{ See if the value has already been reserved for another CMOV instruction } { See if the value has already been reserved for another CMOV instruction }
CurrentVal := taicpu(p).oper[0]^.val; CurrentVal := taicpu(p).oper[0]^.val;
for X := 0 to StoredCount - 1 do for X := 0 to StoredCount - 1 do
if (ConstVals[X] = CurrentVal) and if ConstVals[X] = CurrentVal then
(getsubreg(taicpu(p).oper[1]^.reg) <= getsubreg(ConstRegs[X])) then
begin begin
ConstRegs[StoredCount] := newreg(R_INTREGISTER, getsupreg(ConstRegs[X]), RegSize); ConstRegs[StoredCount] := ConstRegs[X];
ConstSizes[StoredCount] := RegSize;
ConstVals[StoredCount] := CurrentVal; ConstVals[StoredCount] := CurrentVal;
Result := True; Result := True;
@ -11762,7 +11769,7 @@ unit aoptx86;
Exit; Exit;
end; end;
ANewReg := GetIntRegisterBetween(RegSize, TmpUsedRegs, search_start_p, stop_search_p, True); ANewReg := GetIntRegisterBetween(R_SUBWHOLE, TmpUsedRegs, search_start_p, stop_search_p, True);
if ANewReg = NR_NO then if ANewReg = NR_NO then
{ No free registers } { No free registers }
Exit; Exit;
@ -11772,6 +11779,7 @@ unit aoptx86;
IncludeRegInUsedRegs(ANewReg, TmpUsedRegs); IncludeRegInUsedRegs(ANewReg, TmpUsedRegs);
ConstRegs[StoredCount] := ANewReg; ConstRegs[StoredCount] := ANewReg;
ConstSizes[StoredCount] := RegSize;
ConstVals[StoredCount] := CurrentVal; ConstVals[StoredCount] := CurrentVal;
Inc(StoredCount); Inc(StoredCount);
@ -12242,10 +12250,13 @@ unit aoptx86;
l := 0; l := 0;
c := 0; c := 0;
{ Initialise RegWrites, ConstRegs and ConstVals } { Initialise RegWrites, ConstRegs, ConstVals, ConstSizes, ConstWriteSizes and ConstMovs }
FillChar(RegWrites[0], MAX_CMOV_INSTRUCTIONS * 2 * SizeOf(TRegister), 0); FillChar(RegWrites[0], MAX_CMOV_INSTRUCTIONS * 2 * SizeOf(TRegister), 0);
FillChar(ConstRegs[0], MAX_CMOV_REGISTERS * SizeOf(TRegister), 0); FillChar(ConstRegs[0], MAX_CMOV_REGISTERS * SizeOf(TRegister), 0);
FillChar(ConstVals[0], MAX_CMOV_REGISTERS * SizeOf(TCGInt), 0); FillChar(ConstVals[0], MAX_CMOV_REGISTERS * SizeOf(TCGInt), 0);
FillChar(ConstSizes[0], MAX_CMOV_REGISTERS * SizeOf(TSubRegister), 0);
FillChar(ConstWriteSizes[0], first_int_imreg * SizeOf(TOpSize), 0);
FillChar(ConstMovs[0], MAX_CMOV_REGISTERS * SizeOf(taicpu), 0);
RefModified := False; RefModified := False;
while assigned(hp1) and while assigned(hp1) and
@ -12341,7 +12352,7 @@ unit aoptx86;
below) } below) }
if not TmpUsedRegs[R_INTREGISTER].IsUsed(ConstRegs[x]) then if not TmpUsedRegs[R_INTREGISTER].IsUsed(ConstRegs[x]) then
begin begin
hp_new := taicpu.op_const_reg(A_MOV, reg2opsize(ConstRegs[x]), taicpu(hp1).oper[0]^.val, ConstRegs[x]); hp_new := taicpu.op_const_reg(A_MOV, subreg2opsize[R_SUBWHOLE], taicpu(hp1).oper[0]^.val, ConstRegs[X]);
taicpu(hp_new).fileinfo := taicpu(hp_prev).fileinfo; taicpu(hp_new).fileinfo := taicpu(hp_prev).fileinfo;
asml.InsertBefore(hp_new, hp_flagalloc); asml.InsertBefore(hp_new, hp_flagalloc);
@ -12349,14 +12360,20 @@ unit aoptx86;
TrySwapMovOp(hp_prev2, hp_new); TrySwapMovOp(hp_prev2, hp_new);
IncludeRegInUsedRegs(ConstRegs[x], TmpUsedRegs); IncludeRegInUsedRegs(ConstRegs[x], TmpUsedRegs);
ConstMovs[X] := hp_new;
end end
else else
{ We just need an instruction between hp_prev and hp1 { We just need an instruction between hp_prev and hp1
where we know the register is marked as in use } where we know the register is marked as in use }
hp_new := hpmov1; hp_new := hpmov1;
{ Keep track of largest write for this register so it can be optimised later }
if (getsubreg(taicpu(hp1).oper[1]^.reg) > ConstWriteSizes[getsupreg(ConstRegs[X])]) then
ConstWriteSizes[getsupreg(ConstRegs[X])] := getsubreg(taicpu(hp1).oper[1]^.reg);
AllocRegBetween(ConstRegs[x], hp_new, hp1, UsedRegs); AllocRegBetween(ConstRegs[x], hp_new, hp1, UsedRegs);
taicpu(hp1).loadreg(0, newreg(R_INTREGISTER, getsupreg(ConstRegs[X]), getsubreg(taicpu(hp1).oper[1]^.reg))); taicpu(hp1).loadreg(0, newreg(R_INTREGISTER, getsupreg(ConstRegs[X]), ConstSizes[X]));
Inc(x); Inc(x);
end; end;
@ -12368,6 +12385,14 @@ unit aoptx86;
GetNextInstruction(hp1, hp1); GetNextInstruction(hp1, hp1);
until (hp1 = hp_lblxxx); until (hp1 = hp_lblxxx);
{ Update initialisation MOVs to the smallest possible size }
for c := 0 to x - 1 do
if Assigned(ConstMovs[c]) then
begin
taicpu(ConstMovs[c]).opsize := subreg2opsize[ConstWriteSizes[Word(ConstRegs[c])]];
setsubreg(taicpu(ConstMovs[c]).oper[1]^.reg, ConstWriteSizes[Word(ConstRegs[c])]);
end;
hp2 := hp_lblxxx; hp2 := hp_lblxxx;
repeat repeat
if not Assigned(hp2) then if not Assigned(hp2) then
@ -12595,7 +12620,7 @@ unit aoptx86;
for x := 0 to c - 1 do for x := 0 to c - 1 do
if (ConstVals[x] = taicpu(hp1).oper[0]^.val) and if (ConstVals[x] = taicpu(hp1).oper[0]^.val) and
(getsubreg(taicpu(hp1).oper[1]^.reg) <= getsubreg(ConstRegs[X])) then (getsubreg(taicpu(hp1).oper[1]^.reg) = ConstSizes[X]) then
begin begin
RegMatch := True; RegMatch := True;
@ -12606,20 +12631,26 @@ unit aoptx86;
below) } below) }
if not TmpUsedRegs[R_INTREGISTER].IsUsed(ConstRegs[x]) then if not TmpUsedRegs[R_INTREGISTER].IsUsed(ConstRegs[x]) then
begin begin
hp_new := taicpu.op_const_reg(A_MOV, reg2opsize(ConstRegs[X]), taicpu(hp1).oper[0]^.val, ConstRegs[X]); hp_new := taicpu.op_const_reg(A_MOV, subreg2opsize[R_SUBWHOLE], taicpu(hp1).oper[0]^.val, ConstRegs[X]);
asml.InsertBefore(hp_new, hp_flagalloc); asml.InsertBefore(hp_new, hp_flagalloc);
if Assigned(hp_prev2) then if Assigned(hp_prev2) then
TrySwapMovOp(hp_prev2, hp_new); TrySwapMovOp(hp_prev2, hp_new);
IncludeRegInUsedRegs(ConstRegs[x], TmpUsedRegs); IncludeRegInUsedRegs(ConstRegs[x], TmpUsedRegs);
ConstMovs[X] := hp_new;
end end
else else
{ We just need an instruction between hp_prev and hp1 { We just need an instruction between hp_prev and hp1
where we know the register is marked as in use } where we know the register is marked as in use }
hp_new := hpmov2; hp_new := hpmov2;
{ Keep track of largest write for this register so it can be optimised later }
if (getsubreg(taicpu(hp1).oper[1]^.reg) > ConstWriteSizes[getsupreg(ConstRegs[X])]) then
ConstWriteSizes[getsupreg(ConstRegs[X])] := getsubreg(taicpu(hp1).oper[1]^.reg);
AllocRegBetween(ConstRegs[x], hp_new, hp1, UsedRegs); AllocRegBetween(ConstRegs[x], hp_new, hp1, UsedRegs);
taicpu(hp1).loadreg(0, newreg(R_INTREGISTER, getsupreg(ConstRegs[X]), getsubreg(taicpu(hp1).oper[1]^.reg))); taicpu(hp1).loadreg(0, newreg(R_INTREGISTER, getsupreg(ConstRegs[X]), ConstSizes[X]));
Break; Break;
end; end;
@ -12678,7 +12709,7 @@ unit aoptx86;
for x := 0 to c - 1 do for x := 0 to c - 1 do
if (ConstVals[x] = taicpu(hp1).oper[0]^.val) and if (ConstVals[x] = taicpu(hp1).oper[0]^.val) and
(getsubreg(taicpu(hp1).oper[1]^.reg) <= getsubreg(ConstRegs[X])) then (getsubreg(taicpu(hp1).oper[1]^.reg) = ConstSizes[X]) then
begin begin
RegMatch := True; RegMatch := True;
@ -12689,20 +12720,26 @@ unit aoptx86;
below) } below) }
if not TmpUsedRegs[R_INTREGISTER].IsUsed(ConstRegs[x]) then if not TmpUsedRegs[R_INTREGISTER].IsUsed(ConstRegs[x]) then
begin begin
hp_new := taicpu.op_const_reg(A_MOV, reg2opsize(ConstRegs[X]), taicpu(hp1).oper[0]^.val, ConstRegs[X]); hp_new := taicpu.op_const_reg(A_MOV, subreg2opsize[R_SUBWHOLE], taicpu(hp1).oper[0]^.val, ConstRegs[X]);
asml.InsertBefore(hp_new, hp_flagalloc); asml.InsertBefore(hp_new, hp_flagalloc);
if Assigned(hp_prev2) then if Assigned(hp_prev2) then
TrySwapMovOp(hp_prev2, hp_new); TrySwapMovOp(hp_prev2, hp_new);
IncludeRegInUsedRegs(ConstRegs[x], TmpUsedRegs); IncludeRegInUsedRegs(ConstRegs[x], TmpUsedRegs);
ConstMovs[X] := hp_new;
end end
else else
{ We just need an instruction between hp_prev and hp1 { We just need an instruction between hp_prev and hp1
where we know the register is marked as in use } where we know the register is marked as in use }
hp_new := hpmov1; hp_new := hpmov1;
{ Keep track of largest write for this register so it can be optimised later }
if (getsubreg(taicpu(hp1).oper[1]^.reg) > ConstWriteSizes[getsupreg(ConstRegs[X])]) then
ConstWriteSizes[getsupreg(ConstRegs[X])] := getsubreg(taicpu(hp1).oper[1]^.reg);
AllocRegBetween(ConstRegs[x], hp_new, hp1, UsedRegs); AllocRegBetween(ConstRegs[x], hp_new, hp1, UsedRegs);
taicpu(hp1).loadreg(0, newreg(R_INTREGISTER, getsupreg(ConstRegs[X]), getsubreg(taicpu(hp1).oper[1]^.reg))); taicpu(hp1).loadreg(0, newreg(R_INTREGISTER, getsupreg(ConstRegs[X]), ConstSizes[X]));
Break; Break;
end; end;
@ -12717,6 +12754,14 @@ unit aoptx86;
GetNextInstruction(hp1, hp1); GetNextInstruction(hp1, hp1);
until (hp1 = hp_jump); { Stop at the jump, not lbl xxx } until (hp1 = hp_jump); { Stop at the jump, not lbl xxx }
{ Update initialisation MOVs to the smallest possible size }
for x := 0 to c - 1 do
if Assigned(ConstMovs[x]) then
begin
taicpu(ConstMovs[x]).opsize := subreg2opsize[ConstWriteSizes[Word(ConstRegs[x])]];
setsubreg(taicpu(ConstMovs[x]).oper[1]^.reg, ConstWriteSizes[Word(ConstRegs[x])]);
end;
UpdateUsedRegs(tai(hp_jump.next)); UpdateUsedRegs(tai(hp_jump.next));
UpdateUsedRegs(tai(hp_lblyyy.next)); UpdateUsedRegs(tai(hp_lblyyy.next));