search for: cmov_fr64

Hi Bill. Thank you very much! Now I see my understanding was incorrect :) A dependence from a single physreg-defining instruction (like CMP or TEST) is allowed to be shared in several instructions unless that register is not clobbered (and this is what we have with CMOV_FR64). Wouldn't it be safe then to not set the live-in flag in EmitLoweredSelect for instructions which are marked as defining EFLAGS (like the integer pseudo cmovs)? Thanks, Sergey -----Original Message----- From: Bill Wendling [mailto:wendling at apple.com] Sent: Thursday, June 02, 2011 12:00 A...

...v, Sergey wrote: > Hi Bill. > > Thank you very much! Now I see my understanding was incorrect :) A dependence from a single physreg-defining instruction (like CMP or TEST) is allowed to be shared in several instructions unless that register is not clobbered (and this is what we have with CMOV_FR64). Wouldn't it be safe then to not set the live-in flag in EmitLoweredSelect for instructions which are marked as defining EFLAGS (like the integer pseudo cmovs)? > Hi Sergey, I'm not certain what that would buy us. If I understand your suggestion correctly, not setting the EFLAGS as li...

...> >> Hi Bill. >> >> Thank you very much! Now I see my understanding was incorrect :) A dependence from a single physreg-defining instruction (like CMP or TEST) is allowed to be shared in several instructions unless that register is not clobbered (and this is what we have with CMOV_FR64). Wouldn't it be safe then to not set the live-in flag in EmitLoweredSelect for instructions which are marked as defining EFLAGS (like the integer pseudo cmovs)? >> > Hi Sergey, > > I'm not certain what that would buy us. If I understand your suggestion correctly, not setti...

...> >> Hi Bill. >> >> Thank you very much! Now I see my understanding was incorrect :) A dependence from a single physreg-defining instruction (like CMP or TEST) is allowed to be shared in several instructions unless that register is not clobbered (and this is what we have with CMOV_FR64). Wouldn't it be safe then to not set the live-in flag in EmitLoweredSelect for instructions which are marked as defining EFLAGS (like the integer pseudo cmovs)? >> > Hi Sergey, > > I'm not certain what that would buy us. If I understand your suggestion correctly, not setti...

...t;> Hi Bill. >>> >>> Thank you very much! Now I see my understanding was incorrect :) A dependence from a single physreg-defining instruction (like CMP or TEST) is allowed to be shared in several instructions unless that register is not clobbered (and this is what we have with CMOV_FR64). Wouldn't it be safe then to not set the live-in flag in EmitLoweredSelect for instructions which are marked as defining EFLAGS (like the integer pseudo cmovs)? >>> >> Hi Sergey, >> >> I'm not certain what that would buy us. If I understand your suggestion corr...

On Jun 1, 2011, at 9:18 AM, Galanov, Sergey wrote: > Hello. > > I am not sure this is the right place to ask but here is my question. About a year ago there was a fix of some obscure bug (rdar://problem/8030636 which is located on the internal Apple bugtracker I believe and so not available to the general public J) > Some discussion can be found here:

Hello. I am not sure this is the right place to ask but here is my question. About a year ago there was a fix of some obscure bug (rdar://problem/8030636 which is located on the internal Apple bugtracker I believe and so not available to the general public :)) Some discussion can be found here: http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20100531/102160.html. Unfortunately, no

...t;> Hi Bill. >>> >>> Thank you very much! Now I see my understanding was incorrect :) A dependence from a single physreg-defining instruction (like CMP or TEST) is allowed to be shared in several instructions unless that register is not clobbered (and this is what we have with CMOV_FR64). Wouldn't it be safe then to not set the live-in flag in EmitLoweredSelect for instructions which are marked as defining EFLAGS (like the integer pseudo cmovs)? >>> >> Hi Sergey, >> >> I'm not certain what that would buy us. If I understand your suggestion corr...