...jmp *.L11(,%%rax,8) I guess the MOV is there to get enough distance between the two jumps. But does it have to use %%eax (on which the next instruction depends)? And if we want an instruction in between, we could split the JMP and use a 32-bit switch table: movl %%eax,.L11(,%%rax,4) jmp *%%rax Yes, it looks like a 32-bit switch table would be better. Andrew.

... the two jumps. But does it have to use %%eax (on which the next instruction depends)? And if we want an instruction in between, we could split the JMP and use a 32-bit switch table: movl %%eax,.L11(,%%rax,4) jmp *%%rax - anton -- M. Anton Ertl http://www.complang.tuwien.ac.at/anton/home.html comp.lang.forth FAQs: http://www.complang.tuwien.ac.at/forth/faq/toc.html New ...

..., as it should be for accesses to cpu0pdb. And ... it dies in gotolabel here: TEXT gotolabel(SB), $1 MOVL label+0(FP), AX MOVL 0(AX), SP /* restore sp */ MOVL 4(AX), AX /* put return pc on the stack */ MOVL AX, 0(SP) MOVL $1, AX /* return 1 */ DIE DIE DIE RET as determined by me putting ...

... number and lookup using an open hash table. Dispatch can be done with something like movl %%eax, %%edx andl mtable_size, %%edx .retry: movl mtable(,%%edx,8), %%ecx cmpl %%eax, %%ecx jne .next call *mtable+4(,%%edx,8) .next: ... probe ...

... 8(%%rsp) movq 8(%%rsp), %%rax movl (%%rax), %%eax xorl $1, %%eax...(%%rsp) movq 8(%%rsp), %%rax movl (%%rax), %%eax xorl $1, %%eax...(%%rsp) movq 8(%%rsp), %%rax movl (%%rax), %%eax testl %%eax, %%eax...L8 movq 16(%%rsp), %%rax movl (%%rax), %%eax testl %%eax, %%eax...

..., as it should be for accesses to cpu0pdb. And ... it dies in gotolabel here: TEXT gotolabel(SB), $1 MOVL label+0(FP), AX MOVL 0(AX), SP /* restore sp */ MOVL 4(AX), AX /* put return pc on the stack */ MOVL AX, 0(SP) MOVL $1, AX /* return 1 */ DIE DIE DIE RET as determined by me putting calls to lguest ...

..., %%esp pushl -4(%%ecx) pushl %%ebp movl %%esp, %%ebp pushl %%ecx subl $20, ...eax movl %%eax, (%%esp) call b movl %%eax, -8(%%ebp) .L4: cmpl $999999999, -8... cmpl $1000000000, -8(%%ebp) je .L10 movl $.LC0, (%%esp) call puts .L10: addl ...

... starts with: 83 ec 48: SUBL 0x48, SP And the following opcode is: 89 05 xx xx xx xx: MOVL AX, _tos(SB). As a hack, as I'm padding the executables anyway, I check for those bytes and change 89 05 to 89 1D during the padding - which makes the instruction MOVL BX, _tos(SB). I set BX to the proper value in the loader (which is preserved by linux), and voila!...

...sure enough: acid: asm(0x9fe4) _main SUBL $0x48, SP _main+0x3 MOVL AX, _tos(SB) ... So (MOVL, _tos(SB)) is definitely executed, but for some reason, the value of AX is not stored in 0x16084..... Does the symbol table need to be in memory too for instructions like (MOVL AX, _tos(SB)) to work? No, the symbol table is only for debuggers ...

... is 0x9fe4, and sure enough: acid: asm(0x9fe4) _main SUBL $0x48, SP _main+0x3 MOVL AX, _tos(SB) ... So (MOVL, _tos(SB)) is definitely executed, but for some reason, the value of AX is not stored in 0x16084. That ... it. Does the symbol table need to be in memory too for instructions like (MOVL AX, _tos(SB)) to work? Regards, Anant