paweld/fpc
1
0
Fork 0
mirror of https://gitlab.com/freepascal.org/fpc/source.git synced 2025-09-14 09:29:19 +02:00
Code Issues Packages Projects Releases Wiki Activity

+ better precision in determining the registers, read by mul/imul/div/idiv in

Browse Source 
i386's TCpuAsmOptimizer.RegReadByInstruction:
  * mul doesn't read edx (unless included in operand)
  * 8-bit mul and imul don't read ah (unless included in operand)
  * 8-bit div and idiv don't read edx (unless included in operand)

git-svn-id: trunk@35958 -
This commit is contained in:
nickysn 2017-04-26 16:17:31 +00:00
parent 916c09af55
commit 0f010430cc
1 changed files with 21 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

26
compiler/i386/aoptcpu.pas
View File

@ -160,17 +160,33 @@ unit aoptcpu;
A_IMUL: A_IMUL:
case p.ops of case p.ops of
1: 1:
regReadByInstruction := regReadByInstruction := RegInOp(reg,p.oper[0]^) or
(reg = NR_EAX) or RegInOp(reg,p.oper[0]^); (
((getregtype(reg)=R_INTREGISTER) and (getsupreg(reg)=RS_EAX)) and
((getsubreg(reg)<>R_SUBH) or (p.opsize<>S_B))
);
2,3: 2,3:
regReadByInstruction := regReadByInstruction :=
reginop(reg,p.oper[0]^) or reginop(reg,p.oper[0]^) or
reginop(reg,p.oper[1]^); reginop(reg,p.oper[1]^);
end; end;
A_IDIV,A_DIV,A_MUL: A_MUL:
begin begin
regReadByInstruction := regReadByInstruction := RegInOp(reg,p.oper[0]^) or
RegInOp(reg,p.oper[0]^) or ((getregtype(reg)=R_INTREGISTER) and (getsupreg(reg) in [RS_EAX,RS_EDX])); (
((getregtype(reg)=R_INTREGISTER) and (getsupreg(reg)=RS_EAX)) and
((getsubreg(reg)<>R_SUBH) or (p.opsize<>S_B))
);
end;
A_IDIV,A_DIV:
begin
regReadByInstruction := RegInOp(reg,p.oper[0]^) or
(
(getregtype(reg)=R_INTREGISTER) and
(
(getsupreg(reg)=RS_EAX) or ((getsupreg(reg)=RS_EDX) and (p.opsize<>S_B))
)
);
end; end;
else else
begin begin