Maybe it's because I've got a lot of two machine operand instructions and have to rely on the tied-to constraint, but I'm seeing a lot of dead reg-to-reg copy instructions, e.g.: ori $3, $3, 0 (Cell SPU's version of reg-to-reg copy, looks a lot like PPC, no?) Is there any way I can detect when this occurs, or is there code where this detection takes place in the target to which I can refer? -scooter -- Scott Michel scottm at aero.org High Performance Hardware Section Manager 310/336-5034 Computer Systems Research Department The Aerospace Corporation
On 1/18/07, Scott Michel <scottm at rushg.aero.org> wrote:> Is there any way I can detect when this occurs, or is there code > where this detection takes place in the target to which I can > refer?have you implemented InstInfo::isMoveInstr to recognize those? The register allocator uses that to find copies it can remove. Andrew
Just independently discovered this... Thanks! -scooter On Jan 18, 2007, at 11:52 AM, Andrew Lenharth wrote:> On 1/18/07, Scott Michel <scottm at rushg.aero.org> wrote: >> Is there any way I can detect when this occurs, or is there code >> where this detection takes place in the target to which I can >> refer? > > have you implemented InstInfo::isMoveInstr to recognize those? The > register allocator uses that to find copies it can remove. > > Andrew > _______________________________________________ > LLVM Developers mailing list > LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev