diff options
Diffstat (limited to 'mips/compiler/mips/aasmcpu.pas')
| -rw-r--r-- | mips/compiler/mips/aasmcpu.pas | 147 |
1 files changed, 146 insertions, 1 deletions
diff --git a/mips/compiler/mips/aasmcpu.pas b/mips/compiler/mips/aasmcpu.pas index 065e23d67f..4493fb5abd 100644 --- a/mips/compiler/mips/aasmcpu.pas +++ b/mips/compiler/mips/aasmcpu.pas @@ -28,7 +28,7 @@ interface uses cclasses, globtype, globals, verbose, - aasmbase, aasmsym, aasmtai, + aasmbase, aasmdata, aasmsym, aasmtai, cgbase, cgutils, cpubase, cpuinfo; const @@ -78,11 +78,16 @@ type procedure InitAsm; procedure DoneAsm; + procedure fixup_jmps(list: TAsmList); + function spilling_create_load(const ref: treference; r: tregister): taicpu; function spilling_create_store(r: tregister; const ref: treference): taicpu; implementation + uses + cutils; + {***************************************************************************** taicpu Constructors *****************************************************************************} @@ -452,6 +457,146 @@ procedure DoneAsm; end; +procedure fixup_jmps(list: TAsmList); + var + p,pdelayslot: tai; + newcomment: tai_comment; + newjmp,newnoop: taicpu; + labelpositions: TFPList; + instrpos: ptrint; + l: tasmlabel; + inserted_something: boolean; + begin + // if certainly not enough instructions to cause an overflow, dont bother + if (list.count <= (high(smallint) div 4)) then + exit; + labelpositions := TFPList.create; + p := tai(list.first); + instrpos := 1; + // record label positions + while assigned(p) do + begin + if p.typ = ait_label then + begin + if (tai_label(p).labsym.labelnr >= labelpositions.count) then + labelpositions.count := tai_label(p).labsym.labelnr * 2; + labelpositions[tai_label(p).labsym.labelnr] := pointer(instrpos); + end; + { ait_const is for jump tables } + case p.typ of + ait_instruction: + { probleim here: pseudo-instructions can translate into + several CPU instructions, possibly depending on assembler options, + to obe on safe side, let's assume a mean of two. } + inc(instrpos,2); + ait_const: + begin + if (tai_const(p).consttype<>aitconst_32bit) then + internalerror(2008052101); + inc(instrpos); + end; + end; + p := tai(p.next); + end; + + { If the number of instructions is below limit, we can't overflow either } + if (instrpos <= (high(smallint) div 4)) then + exit; + // check and fix distances + repeat + inserted_something := false; + p := tai(list.first); + instrpos := 1; + while assigned(p) do + begin + case p.typ of + ait_label: + // update labelposition in case it changed due to insertion + // of jumps + begin + // can happen because of newly inserted labels + if (tai_label(p).labsym.labelnr > labelpositions.count) then + labelpositions.count := tai_label(p).labsym.labelnr * 2; + labelpositions[tai_label(p).labsym.labelnr] := pointer(instrpos); + end; + ait_instruction: + begin + inc(instrpos,2); + case taicpu(p).opcode of + A_BA: + if (taicpu(p).oper[0]^.typ = top_ref) and + assigned(taicpu(p).oper[0]^.ref^.symbol) and + (taicpu(p).oper[0]^.ref^.symbol is tasmlabel) and + (labelpositions[tasmlabel(taicpu(p).oper[0]^.ref^.symbol).labelnr] <> NIL) and +{$push} +{$q-} + (ptruint(abs(ptrint(labelpositions[tasmlabel(taicpu(p).oper[0]^.ref^.symbol).labelnr]-instrpos)) - (low(smallint) div 4)) > ptruint((high(smallint) - low(smallint)) div 4)) then +{$pop} + begin + { This is not PIC safe } + taicpu(p).opcode:=A_J; + newcomment:=tai_comment.create(strpnew('fixup_jmps, A_BA changed into A_J')); + list.insertbefore(newcomment,p); + end; + A_BC: + if (taicpu(p).ops=3) and (taicpu(p).oper[2]^.typ = top_ref) and + assigned(taicpu(p).oper[2]^.ref^.symbol) and + (taicpu(p).oper[2]^.ref^.symbol is tasmlabel) and + (labelpositions[tasmlabel(taicpu(p).oper[2]^.ref^.symbol).labelnr] <> NIL) and +{$push} +{$q-} + (ptruint(abs(ptrint(labelpositions[tasmlabel(taicpu(p).oper[2]^.ref^.symbol).labelnr]-instrpos)) - (low(smallint) div 4)) > ptruint((high(smallint) - low(smallint)) div 4)) then +{$pop} + begin + // add a new label after this jump + current_asmdata.getjumplabel(l); + { new label -> may have to increase array size } + if (l.labelnr >= labelpositions.count) then + labelpositions.count := l.labelnr + 10; + { newjmp will be inserted before the label, and it's inserted after } + { plus delay slot } + { the current jump -> instrpos+3 } + labelpositions[l.labelnr] := pointer(instrpos+2*3); + pdelayslot:=tai(p.next); + { We need to insert the new instruction after the delay slot instruction ! } + while assigned(pdelayslot) and (pdelayslot.typ<>ait_instruction) do + pdelayslot:=tai(pdelayslot.next); + + list.insertafter(tai_label.create(l),pdelayslot); + // add a new unconditional jump between this jump and the label + newcomment:=tai_comment.create(strpnew('fixup_jmps, A_BXX changed into A_BNOTXX label;A_J;label:')); + list.insertbefore(newcomment,p); + newjmp := taicpu.op_sym(A_J,taicpu(p).oper[2]^.ref^.symbol); + newjmp.is_jmp := true; + newjmp.fileinfo := taicpu(p).fileinfo; + list.insertafter(newjmp,pdelayslot); + inc(instrpos,2); + { Add a delay slot for new A_J instruction } + newnoop:=taicpu.op_none(A_NOP); + newnoop.fileinfo := taicpu(p).fileinfo; + list.insertafter(newnoop,newjmp); + inc(instrpos,2); + // change the conditional jump to point to the newly inserted label + tasmlabel(taicpu(p).oper[2]^.ref^.symbol).decrefs; + taicpu(p).oper[2]^.ref^.symbol := l; + l.increfs; + // and invert its condition code + taicpu(p).condition := inverse_cond(taicpu(p).condition); + // we inserted an instruction, so will have to check everything again + inserted_something := true; + end; + end; + end; + ait_const: + inc(instrpos); + end; + p := tai(p.next); + end; + until not inserted_something; + labelpositions.free; + end; + + begin cai_cpu := taicpu; cai_align := tai_align; |