paweld/fpc
1
0
Fork 0
mirror of https://gitlab.com/freepascal.org/fpc/source.git synced 2025-04-18 05:39:26 +02:00
Code Issues Packages Projects Releases Wiki Activity

Optimize Add/Sub+Ldr/Str by using preindexed references

Browse Source 
git-svn-id: trunk@24789 -
This commit is contained in:
Jeppe Johansen 2013-06-02 21:51:12 +00:00
parent f8a6ddd460
commit f3273fa87d
1 changed files with 65 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

65
compiler/arm/aoptcpu.pas
View File

@ -57,6 +57,7 @@ Type
private
function SkipEntryExitMarker(current: tai; var next: tai): boolean;
protected
function LookForPreindexedPattern(p: taicpu): boolean;
function LookForPostindexedPattern(p: taicpu): boolean;
End;
@ -405,6 +406,60 @@ Implementation
end;
end;
{
optimize
add/sub reg1,reg1,regY/const
...
ldr/str regX,[reg1]
into
ldr/str regX,[reg1, regY/const]!
}
function TCpuAsmOptimizer.LookForPreindexedPattern(p: taicpu): boolean;
var
hp1: tai;
begin
if (p.ops=3) and
MatchOperand(p.oper[0]^, p.oper[1]^.reg) and
GetNextInstructionUsingReg(p, hp1, p.oper[0]^.reg) and
(not RegModifiedBetween(p.oper[0]^.reg, p, hp1)) and
MatchInstruction(hp1, [A_LDR,A_STR], [C_None], [PF_None,PF_B,PF_H,PF_SH,PF_SB]) and
(taicpu(hp1).oper[1]^.ref^.addressmode=AM_OFFSET) and
(taicpu(hp1).oper[1]^.ref^.base=p.oper[0]^.reg) and
(taicpu(hp1).oper[0]^.reg<>p.oper[0]^.reg) and
(taicpu(hp1).oper[1]^.ref^.offset=0) and
(taicpu(hp1).oper[1]^.ref^.index=NR_NO) and
(((p.oper[2]^.typ=top_reg) and
(not RegModifiedBetween(p.oper[2]^.reg, p, hp1))) or
((p.oper[2]^.typ=top_const) and
((abs(p.oper[2]^.val) < 256) or
((abs(p.oper[2]^.val) < 4096) and
(taicpu(hp1).oppostfix in [PF_None,PF_B]))))) then
begin
taicpu(hp1).oper[1]^.ref^.addressmode:=AM_PREINDEXED;
if p.oper[2]^.typ=top_reg then
begin
taicpu(hp1).oper[1]^.ref^.index:=p.oper[2]^.reg;
if p.opcode=A_ADD then
taicpu(hp1).oper[1]^.ref^.signindex:=1
else
taicpu(hp1).oper[1]^.ref^.signindex:=-1;
end
else
begin
if p.opcode=A_ADD then
taicpu(hp1).oper[1]^.ref^.offset:=p.oper[2]^.val
else
taicpu(hp1).oper[1]^.ref^.offset:=-p.oper[2]^.val;
end;
result:=true;
end
else
result:=false;
end;
{
optimize
@ -1467,6 +1522,16 @@ Implementation
if (taicpu(p).ops=3) then
RemoveSuperfluousMove(p, hp1, 'DataMov2Data');
end;
if MatchInstruction(p, [A_ADD,A_SUB], [C_None], [PF_None]) and
LookForPreindexedPattern(taicpu(p)) then
begin
GetNextInstruction(p,hp1);
DebugMsg('Peephole Add/Sub to Preindexed done', p);
asml.remove(p);
p.free;
p:=hp1;
end;
end;
{$ifdef dummy}
A_MVN: