search for: printasmoperand

I was wondering if llvm supports sub registers in an inline asm string. For example, in gcc, using modifiers %w0 makes it possible to access ax if %0 refers to eax. If there is any support, do you know where it is implemented ? I'd like to add such a support for another target. Thank you ! Damien -------------- next part -------------- An HTML attachment was scrubbed... URL:

...it possible to access ax if %0 refers to eax. > > If there is any support, do you know where it is implemented ? I'd like to add such a support for another target. Hi Damien, It sure does. These are considered "modifier" characters and are handled in (e.g.) X86AsmPrinter::PrintAsmOperand. You can send some C code with asms in it through x86 clang to see what IR it generates or use the llvm demo page. -Chris

...r &P, const MachineOperand &MO, break; } - O << '%' << X86ATTInstPrinter::getRegisterName(Reg); + if (emit_pct) + O << '%'; + + O << X86ATTInstPrinter::getRegisterName(Reg); return false; } @@ -464,6 +472,7 @@ bool X86AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo, case 'w': // Print HImode register case 'k': // Print SImode register case 'q': // Print DImode register + case 'V': // Print native register without '%' if (MO.isReg()) return printAsmM...

...> } > > - O << '%' << X86ATTInstPrinter::getRegisterName(Reg); > + if (emit_pct) > + O << '%'; > + > + O << X86ATTInstPrinter::getRegisterName(Reg); > return false; > } > > @@ -464,6 +472,7 @@ bool X86AsmPrinter::PrintAsmOperand(const MachineInstr > *MI, unsigned OpNo, > case 'w': // Print HImode register > case 'k': // Print SImode register > case 'q': // Print DImode register > + case 'V': // Print native register without '%' > if (MO.isRe...

On Wed, 2018-02-07 at 13:16 -0800, Guenter Roeck wrote: > Here are my exact versions: >     llvm: 3afd566557f3 ("AMDGPU: Add 32-bit constant address space") >     clang: 848874aed95a ("[clang-format] Fix ObjC message arguments formatting.") OK, mine are slightly newer than that now, but I now get a working 64- bit defconfig build. It'll still break with any PV

In r198030 the last in tree backend was converted to use MCInst for printing assembly. I removed support for the old printer in r198959. Out of tree targets have to lower MachineInstr to MCInst to use the new printer. Cheers, Rafael

On Wed, Feb 07, 2018 at 08:44:32PM +0000, David Woodhouse wrote: > On Wed, 2018-02-07 at 10:11 -0800, Guenter Roeck wrote: > > > On Wed, Feb 07, 2018 at 10:49:25AM +0000, David Woodhouse wrote: > > > Hm, please could we also have the %V asm constraint modifier? That > > > allows us to emit calls to the thunks from inline asm using the > > > register that the