Mercurial > pub > dyncall > dyncall
diff doc/disas_examples/mips.o32.disas @ 497:cb19b2fe2422
- more disas examples to check behaviour of passing C++ non-trivial aggregates by value; they all behave the same, calling the copy ctor first, passing a pointer then
| author | Tassilo Philipp |
|---|---|
| date | Wed, 23 Mar 2022 15:24:31 +0100 |
| parents | 6c72cb768099 |
| children | fd9ba3a6d348 |
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--- a/doc/disas_examples/mips.o32.disas Mon Mar 21 18:11:38 2022 +0100 +++ b/doc/disas_examples/mips.o32.disas Wed Mar 23 15:24:31 2022 +0100 @@ -1754,5 +1754,113 @@ +; ---------- C++ trivial and non-trivial aggrs passed to C funcs ----------> +; +; struct Trivial { int a; }; +; struct NonTrivial { int a; NonTrivial() : a(0) {} NonTrivial(const NonTrivial& rhs) : a(rhs.a) { } }; +; +; extern "C" { +; +; void f1(struct Trivial s) { } +; void f2(struct NonTrivial s) { } +; +; void f() +; { +; struct Trivial t; +; struct NonTrivial n; +; int a=1; +; a += 123; +; f1(t); +; a -= 123; +; f2(n); +; a -= 12; +; } +; } + + + +; output from freebsd-12.0_r333647-malta_mipsebhf w/ gcc 4.2.1 *and* -mhard-float -----> + +004008c0 <f1>: + 4008c0: 3c1c0002 lui gp,0x2 + 4008c4: 279c8330 addiu gp,gp,-31952 + 4008c8: 0399e021 addu gp,gp,t9 + 4008cc: 27bdfff8 addiu sp,sp,-8 + 4008d0: afbe0000 sw s8,0(sp) + 4008d4: 03a0f021 move s8,sp + 4008d8: afc40008 sw a0,8(s8) + 4008dc: 03c0e821 move sp,s8 + 4008e0: 8fbe0000 lw s8,0(sp) + 4008e4: 03e00008 jr ra + 4008e8: 27bd0008 addiu sp,sp,8 + +004008ec <f2>: + 4008ec: 3c1c0002 lui gp,0x2 + 4008f0: 279c8304 addiu gp,gp,-31996 + 4008f4: 0399e021 addu gp,gp,t9 + 4008f8: 27bdfff8 addiu sp,sp,-8 + 4008fc: afbe0000 sw s8,0(sp) + 400900: 03a0f021 move s8,sp + 400904: afc40008 sw a0,8(s8) + 400908: 03c0e821 move sp,s8 + 40090c: 8fbe0000 lw s8,0(sp) + 400910: 03e00008 jr ra + 400914: 27bd0008 addiu sp,sp,8 + +00400918 <f>: + 400918: 3c1c0002 lui gp,0x2 ; + 40091c: 279c82d8 addiu gp,gp,-32040 ; + 400920: 0399e021 addu gp,gp,t9 ; + 400924: 27bdffd0 addiu sp,sp,-48 ; + 400928: afbf002c sw ra,44(sp) ; + 40092c: afbe0028 sw s8,40(sp) ; + 400930: 03a0f021 move s8,sp ; + 400934: afbc0010 sw gp,16(sp) ; + 400938: 27c20024 addiu v0,s8,36 ; + 40093c: 00402021 move a0,v0 ; + 400940: 8f998064 lw t9,-32668(gp) ; | + 400944: 0320f809 jalr t9 ; | NonTrivial::NonTrivial() / ctor + 400948: 00000000 nop ; + 40094c: 8fdc0010 lw gp,16(s8) ; + 400950: 24020001 li v0,1 ; + 400954: afc20018 sw v0,24(s8) ; + 400958: 8fc20018 lw v0,24(s8) ; + 40095c: 2442007b addiu v0,v0,123 ; + 400960: afc20018 sw v0,24(s8) ; + 400964: 8fc40020 lw a0,32(s8) ; + 400968: 8f998060 lw t9,-32672(gp) ; | + 40096c: 0320f809 jalr t9 ; | call f1(struct Trivial) + 400970: 00000000 nop ; + 400974: 8fdc0010 lw gp,16(s8) ; + 400978: 8fc20018 lw v0,24(s8) ; + 40097c: 2442ff85 addiu v0,v0,-123 ; + 400980: afc20018 sw v0,24(s8) ; + 400984: 27c2001c addiu v0,s8,28 ; + 400988: 27c30024 addiu v1,s8,36 ; + 40098c: 00402021 move a0,v0 ; | ptr to dest of copy of n + 400990: 00602821 move a1,v1 ; | ptr to n + 400994: 8f998050 lw t9,-32688(gp) ; | copy n | + 400998: 0320f809 jalr t9 ; | | NonTrivial::NonTrivial(const NonTrivial&) / copy ctor + 40099c: 00000000 nop ; + 4009a0: 8fdc0010 lw gp,16(s8) ; + 4009a4: 27c2001c addiu v0,s8,28 ; get ptr to copy of n -> v0 + 4009a8: 00402021 move a0,v0 ; f2 arg 0 (ptr to copy of struct NonTrivial), via ptr as non-trivial + 4009ac: 8f998058 lw t9,-32680(gp) ; | + 4009b0: 0320f809 jalr t9 ; | call f2(struct NonTrivial) + 4009b4: 00000000 nop ; + 4009b8: 8fdc0010 lw gp,16(s8) ; + 4009bc: 8fc20018 lw v0,24(s8) ; + 4009c0: 2442fff4 addiu v0,v0,-12 ; + 4009c4: afc20018 sw v0,24(s8) ; + 4009c8: 03c0e821 move sp,s8 ; + 4009cc: 8fbf002c lw ra,44(sp) ; + 4009d0: 8fbe0028 lw s8,40(sp) ; + 4009d4: 03e00008 jr ra ; + 4009d8: 27bd0030 addiu sp,sp,48 ; + + ; ... snip, removed code of ctor and copy ctor ... + + + ; vim: ft=asm