paweld/fpc
1
0
Fork 0
mirror of https://gitlab.com/freepascal.org/fpc/source.git synced 2025-04-16 23:21:57 +02:00
Code Issues Packages Projects Releases Wiki Activity

* made optimization JSR, RTS to JMP more bullet proof, added comment

Browse Source 
git-svn-id: trunk@47750 -
This commit is contained in:
florian 2020-12-10 21:09:20 +00:00
parent 8b7c5666a2
commit bb8c3fd153
1 changed files with 10 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
compiler/m68k/aoptcpu.pas
View File

@ -48,7 +48,7 @@ unit aoptcpu;
Implementation
uses
cutils, aasmcpu, cgutils, globtype, globals, verbose, cpuinfo, itcpugas;
cutils, aasmcpu, cgutils, globtype, globals, verbose, cpuinfo, itcpugas, procinfo, cpupi;
{ Range check must be disabled explicitly as conversions between signed and unsigned
32-bit values are done without explicit typecasts }
@ -398,7 +398,15 @@ unit aoptcpu;
begin
if (cs_opt_level4 in current_settings.optimizerswitches) and
GetNextInstruction(p,next) and
MatchInstruction(next,A_RTS,[S_NO]) then
MatchInstruction(next,A_RTS,[S_NO]) and
{ play safe: if any parameter is pushed on the stack, we cannot to this optimization
as the bottom stack element might be a parameter and not the return address as it is expected
after a call (which we simulate by a jmp)
Actually, as in this case the stack pointer is no used as a frame pointer and
there will be more instructions to restore the stack frame before jsr, so this
is unlikedly to happen }
(current_procinfo.maxpushedparasize=0) then
begin
DebugMsg('Optimizer: JSR, RTS to JMP',p);
taicpu(p).opcode:=A_JMP;