D - inline asm local identifiers
- Sean L. Palmer (24/24) Apr 06 2003 It seems the inline assembler doesn't support local identifiers (for lab...
- Walter (6/30) Apr 07 2003 '@' isn't supported as an identifier character, and 'loop' is an
- Sean L. Palmer (13/48) Apr 07 2003 Ok, sorry, loop was a bad choice for label identifier. It was just for
- Chris Paulson-Ellis (23/26) Apr 08 2003 but
- Walter (12/19) Apr 08 2003 but
- Sean L. Palmer (5/13) Apr 08 2003 Ok. Point taken.
It seems the inline assembler doesn't support local identifiers (for labels)
of the form ident:
void foo()
{
asm
{
mov ecx, 4;
loop: // error about malformed identifier
dec ecx;
jns loop;
}
// blah.blah...
asm
{
mov ecx, 4;
loop: // if you remove the 's, this errors due to
duplicate label
dec ecx;
jns loop;
}
}
Is this a planned feature? Or should labels be limited in scope to the asm
block they're declared in? Or should I just grin and bear it? ;)
Sean
Apr 06 2003
' ' isn't supported as an identifier character, and 'loop' is an instruction, not a label. "Sean L. Palmer" <palmer.sean verizon.net> wrote in message news:b6qlmq$ktb$1 digitaldaemon.com...It seems the inline assembler doesn't support local identifiers (forlabels)of the form ident: void foo() { asm { mov ecx, 4; loop: // error about malformed identifier dec ecx; jns loop; } // blah.blah... asm { mov ecx, 4; loop: // if you remove the 's, this errors due to duplicate label dec ecx; jns loop; } } Is this a planned feature? Or should labels be limited in scope to theasmblock they're declared in? Or should I just grin and bear it? ;) Sean
Apr 07 2003
Ok, sorry, loop was a bad choice for label identifier. It was just for example purposes; the actual label was more like startsse2: So you didn't say, is label scope staying like this? ident means unique local label in every standard macro assembler I can remember. Can you suggest anything? If not, I'll just stick to using unique identifiers, but it makes cut-and-paste much harder. D inline asm doesn't support macros AFAIK. What if we could write 'private mylabel:' to indicate the name isn't visible outside the asm block? Sean "Walter" <walter digitalmars.com> wrote in message news:b6ss2n$jio$2 digitaldaemon.com...' ' isn't supported as an identifier character, and 'loop' is an instruction, not a label. "Sean L. Palmer" <palmer.sean verizon.net> wrote in message news:b6qlmq$ktb$1 digitaldaemon.com...toIt seems the inline assembler doesn't support local identifiers (forlabels)of the form ident: void foo() { asm { mov ecx, 4; loop: // error about malformed identifier dec ecx; jns loop; } // blah.blah... asm { mov ecx, 4; loop: // if you remove the 's, this errors dueduplicate label dec ecx; jns loop; } } Is this a planned feature? Or should labels be limited in scope to theasmblock they're declared in? Or should I just grin and bear it? ;) Sean
Apr 07 2003
"Chris Paulson-Ellis" <chrispe tenornetworks.com> "Sean L. Palmer" <palmer.sean verizon.net> wrote in message news:b6tqt9$1910$1 digitaldaemon.com...Can you suggest anything? If not, I'll just stick to using unique identifiers,butit makes cut-and-paste much harder.In MIPS assembler (not that I would wish to encourage much borrowing from it), you can use a number for a label, say 1:, and then branch to the number either backwards, or forwards by saying 1b or 1f. In my code, most of the labels are 1:, with 2: 3: etc used for nested loops, loop breaks, and such. At first I didn't like it, but it does save you from having to think up local label names. Here is an example (the 1: label is for the loop, and the 2: label implements a conditional block within the loop). ... /* Write value to all locations bytewise. */ 1: sb s4, (t0) /* let us only kick the watchdog every 64K! */ li t8, 0xFFFF and t8, t0, t8 bne t8, zero, 2f nop kick_watchdog (t8, t9) 2: bne t0, s7, 1b addiu t0, 1 ... Chris.
Apr 08 2003
"Sean L. Palmer" <palmer.sean verizon.net> wrote in message news:b6tqt9$1910$1 digitaldaemon.com...So you didn't say, is label scope staying like this? ident means unique local label in every standard macro assembler I can remember. Can you suggest anything? If not, I'll just stick to using unique identifiers,butit makes cut-and-paste much harder. D inline asm doesn't support macros AFAIK. What if we could write 'private mylabel:' to indicate the name isn'tvisibleoutside the asm block?The need for uniquely generated names arises from macro expansion. The D inline assembler isn't a *macro* assembler, as it does not support text substitution macros. Labels in asm blocks have the same scope as other labels, and they are unique to the function they are in (unlike typical macro assemblers). Also, in order to fit successfully with the D compilation model, the inline assembler has to match D's use of tokens, etc. This is why it is case sensitive, rather than insensitive like typical macro assemblers.
Apr 08 2003
Ok. Point taken. Sean "Walter" <walter digitalmars.com> wrote in message news:b6vafl$2d1f$1 digitaldaemon.com...The need for uniquely generated names arises from macro expansion. The D inline assembler isn't a *macro* assembler, as it does not support text substitution macros. Labels in asm blocks have the same scope as other labels, and they are unique to the function they are in (unlike typical macro assemblers). Also, in order to fit successfully with the D compilation model, theinlineassembler has to match D's use of tokens, etc. This is why it is case sensitive, rather than insensitive like typical macro assemblers.
Apr 08 2003