search for: usedpregset

Thanks Lang, I'll try substPhysReg. I did try your latest code, and although it made the assembler errors go away, now some of my tests produce bad output when executed. I need to look into that some more... (I did change my "usedPregSet" to be ALL pregs used in the whole function, not just those in the current instruction, so the problem should not be the erroneous over-writing of a live preg.) Also, I'm confused about the code that gets a preg for a given vreg. Previously,you gave me code that takes into account the...

Hi Susan, The problem now is the usedPregSet. Take the instruction: %vreg13:sub_32bit<def> = ADD32rr %vreg13:sub_32bit, %EAX<kill>, %EFLAGS<imp-def,dead> %EAX will be added to usedPregSet when the instruction is encountered, but %vreg13 is a different class (64bit registers), so none of its candidates will conflict. In add...

Hi Susan, Jakob just pointed me to 'MachineOperand::substPhysReg(unsigned preg, const TargetRegisterInfo& TRI)'. That substitutes the given physreg for a virtreg operand, taking the subregister index into account. That is what my examples have been doing manually. Using substPhysReg would allow you to tidy the Gcra code up slightly. - Lang. On Thu, Nov 15, 2012 at 11:21 AM, Lang

Thanks Jakob. I should have mentioned that earlier. :) When you see mismatched sizes on operands it's a fair bet that the subreg rewriting has gone wrong. I should have pulled that entirely out of the preg search loop in the previous example. Fixed version attached. - Lang. -------------- next part -------------- An HTML attachment was scrubbed... URL:

Lang - Your fix does prevent the assembler errors, but it doesn't seem to produce correct assembly. I created a slightly modified version that, for each instruction that includes a vreg, adds a check that the preg selected is not already in that instruction. I've attached that version. I think that this version of Gcra.cpp should produce correct assembler, since it's allocating

Hi Susan, The problem is that the allocator is re-using the 'preg', which is calculated for an operand that may have a subreg index, for loads and stores to a stack-slot. The stack slot always has the same width as vreg (which is the right behavior), but for operands with subreg indexes, 'preg''s class will be different from 'vreg', in which case you get the mismatched