Mercurial > pub > dyncall > dyncall
comparison doc/disas_examples/arm.armhf.disas @ 499:fc614cb865c6
- doc and disasexample additions specific to non-trivial C++ aggregates as return values (incl. fixes to doc and additional LSB specific PPC32 section)
| author | Tassilo Philipp |
|---|---|
| date | Mon, 04 Apr 2022 15:50:52 +0200 |
| parents | cb19b2fe2422 |
| children |
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| 498:fd9ba3a6d348 | 499:fc614cb865c6 |
|---|---|
| 694 | 694 |
| 695 ; ... snip, removed code of ctor and copy ctor ... | 695 ; ... snip, removed code of ctor and copy ctor ... |
| 696 | 696 |
| 697 | 697 |
| 698 | 698 |
| 699 ; ---------- C++ trivial and non-trivial aggrs as return values ----------> | |
| 700 ; | |
| 701 ; struct Trivial { int a; }; | |
| 702 ; struct NonTrivial { int a; NonTrivial() : a(0) {} NonTrivial(const NonTrivial& rhs) : a(rhs.a) { } }; | |
| 703 ; | |
| 704 ; extern "C" { | |
| 705 ; struct Trivial f1() { return Trivial(); } | |
| 706 ; } | |
| 707 ; | |
| 708 ; struct NonTrivial f2() { return NonTrivial(); } | |
| 709 ; | |
| 710 ; extern "C" { | |
| 711 ; void f() | |
| 712 ; { | |
| 713 ; int a=1; | |
| 714 ; a += 123; | |
| 715 ; struct Trivial t = f1(); | |
| 716 ; a -= 123; | |
| 717 ; struct NonTrivial n = f2(); | |
| 718 ; a -= 12; | |
| 719 ; } | |
| 720 ; } | |
| 721 | |
| 722 | |
| 723 | |
| 724 ; output from raspbian-11-armelhf w/ gcc 10.2.1 | |
| 725 | |
| 726 000103d0 <f1>: | |
| 727 103d0: e52db004 push {fp} | |
| 728 103d4: e28db000 add fp, sp, #0 | |
| 729 103d8: e3a03000 mov r3, #0 | |
| 730 103dc: e1a00003 mov r0, r3 | |
| 731 103e0: e28bd000 add sp, fp, #0 | |
| 732 103e4: e49db004 pop {fp} | |
| 733 103e8: e12fff1e bx lr | |
| 734 | |
| 735 000103ec <_Z2f2v>: | |
| 736 103ec: e92d4800 push {fp, lr} | |
| 737 103f0: e28db004 add fp, sp, #4 | |
| 738 103f4: e24dd008 sub sp, sp, #8 | |
| 739 103f8: e50b0008 str r0, [fp, #-8] | |
| 740 103fc: e51b0008 ldr r0, [fp, #-8] | |
| 741 10400: eb00001f bl 10484 <_ZN10NonTrivialC1Ev> | |
| 742 10404: e51b0008 ldr r0, [fp, #-8] ; ptr to retval space -> r0 | |
| 743 10408: e24bd004 sub sp, fp, #4 | |
| 744 1040c: e8bd8800 pop {fp, pc} | |
| 745 | |
| 746 00010410 <f>: | |
| 747 10410: e92d4800 push {fp, lr} ; | | |
| 748 10414: e28db004 add fp, sp, #4 ; | prolog | |
| 749 10418: e24dd010 sub sp, sp, #16 ; / | |
| 750 1041c: e3a03001 mov r3, #1 ; \ a = 1 | |
| 751 10420: e50b3008 str r3, [fp, #-8] ; / | |
| 752 10424: e51b3008 ldr r3, [fp, #-8] ; \ | |
| 753 10428: e283307b add r3, r3, #123 ; | a += 123 | |
| 754 1042c: e50b3008 str r3, [fp, #-8] ; | | |
| 755 10430: ebffffe6 bl 103d0 <f1> ; call f1() | |
| 756 10434: e1a03000 mov r3, r0 ; | retval via r0, as small struct | |
| 757 10438: e50b300c str r3, [fp, #-12] ; / | |
| 758 1043c: e51b3008 ldr r3, [fp, #-8] ; \ | |
| 759 10440: e243307b sub r3, r3, #123 ; | a -= 123 | |
| 760 10444: e50b3008 str r3, [fp, #-8] ; | | |
| 761 10448: e24b3010 sub r3, fp, #16 ; space to hold non-triv retval -> eax ... | |
| 762 1044c: e1a00003 mov r0, r3 ; ... as hidden first arg (r0) | |
| 763 10450: ebffffe5 bl 103ec <_Z2f2v> ; call f2() | |
| 764 10454: e51b3008 ldr r3, [fp, #-8] ; | | |
| 765 10458: e243300c sub r3, r3, #12 ; | a -= 12 | |
| 766 1045c: e50b3008 str r3, [fp, #-8] ; / | |
| 767 10460: e1a00000 nop ; \ | |
| 768 10464: e24bd004 sub sp, fp, #4 ; | epilog | |
| 769 10468: e8bd8800 pop {fp, pc} ; | | |
| 770 | |
| 771 | |
| 772 | |
| 699 ; vim: ft=asm68k | 773 ; vim: ft=asm68k |
| 700 | 774 |