TSize and TPoint, the other two advanced records defined there, have (well, mostly, they're also missing a couple) all record parameters in their method signatures declared "const", for what is presumably performance / efficiency reasons.
That is to say, record parameters specified without "var", "const", or "constref" have copies made of them 100% of the time regardless of any optimization settings, which results in quite a bit more assembly code being generated and of course slower runtime performance. TRect on the other hand has literally no "const" of any kind for anything except the array called Points in one of the Union method overloads. It seems to me like the original author of this unit probably *intended* to "constify" the methods for TRec the same way they did for TSize and TPoint, but just never got around to it / forgot / something along those lines. I did a little test wherein I extracted the interface and implementation for TRect into a standalone unit, and compared the size of the generated assembly file both as-is and with "const" added in what I believe are the appropriate places. Compiled with native Win64 trunk FPC at -O3, the no-const version was 28KB, while the version with const was 23KB, confirming my expectation that objectively slower / longer assembly is generated without const. As an example, here's the no-const assembly for the "equal" operator overload: .section .text.n_unit1$_$tmyrect_$__$$_equal$tmyrect$tmyrect$$boolean,"x" .balign 16,0x90 .globl UNIT1$_$TMYRECT_$__$$_equal$TMYRECT$TMYRECT$$BOOLEAN UNIT1$_$TMYRECT_$__$$_equal$TMYRECT$TMYRECT$$BOOLEAN: .Lc16: .seh_proc UNIT1$_$TMYRECT_$__$$_equal$TMYRECT$TMYRECT$$BOOLEAN leaq -40(%rsp),%rsp .Lc18: .seh_stackalloc 40 .seh_endprologue movq (%rcx),%rax movq %rax,(%rsp) movq 8(%rcx),%rax movq %rax,8(%rsp) movq (%rdx),%rax movq %rax,16(%rsp) movq 8(%rdx),%rax movq %rax,24(%rsp) movq %rsp,%rax leaq 16(%rsp),%rdx movl (%rax),%ecx cmpl (%rdx),%ecx jne .Lj16 movl 8(%rax),%ecx cmpl 8(%rdx),%ecx jne .Lj16 movl 4(%rax),%ecx cmpl 4(%rdx),%ecx jne .Lj16 movl 12(%rax),%eax cmpl 12(%rdx),%eax jne .Lj16 movb $1,%al jmp .Lj20 .Lj16: xorb %al,%al .Lj20: leaq 40(%rsp),%rsp ret .seh_endproc .Lc17: With const however, it looks like this: .section .text.n_unit1$_$tmyrect_$__$$_equal$tmyrect$tmyrect$$boolean,"x" .balign 16,0x90 .globl UNIT1$_$TMYRECT_$__$$_equal$TMYRECT$TMYRECT$$BOOLEAN UNIT1$_$TMYRECT_$__$$_equal$TMYRECT$TMYRECT$$BOOLEAN: .Lc12: movl (%rcx),%eax cmpl (%rdx),%eax jne .Lj18 movl 8(%rcx),%eax cmpl 8(%rdx),%eax jne .Lj18 movl 4(%rcx),%eax cmpl 4(%rdx),%eax jne .Lj18 movl 12(%rcx),%eax cmpl 12(%rdx),%eax jne .Lj18 movb $1,%al ret .Lj18: xorb %al,%al ret .Lc13: All of that said, I'd be quite happy to prepare and submit a patch that corrects this, assuming it would be accepted and there is not some hidden reason it is the way it is now, which is what I wanted to confirm here.
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