search for: tcc_expensive

...d division doesn't prevent the loop from being unrolled, because it isn't actually considered when loop unrolling. The loop unrolled uses CodeMetrics, which via getUserCost ultimately uses TargetTransformInfoImplBase::getOperationCost(), which returns various fixed values (4 for division (TCC_Expensive, but this isn't nearly expensive enough)). getOperationCost only uses the type and opcode to estimate, so it doesn't require a value. No target overrides this. The hooks that targets do really implement, like getArithmeticInstrCost, use some information about the operands so require a val...

...code that I posted before. This IR code, including the presence of expensive shifts ( %a.lobit = lshr i32 %a, 31) is generated when -mllvm -phi-node-folding-threshold=1 is specified in the command line, or when the Target implements getOperationCost(unsigned Opcode, Type *Ty, Type *OpTy) to return TCC_Expensive for operator types that are bigger than the default target register size. > > > > ; ModuleID = 'main.c' > source_filename = "main.c" > target datalayout = "e-m:e-p:16:16-i32:16-i64:16-f32:16-f64:16-a:8-n8:16-S16" > target triple = "msp430"...

...efore. This IR code, including the presence of > expensive shifts ( %a.lobit = lshr i32 %a, 31) is generated when -mllvm > -phi-node-folding-threshold=1 is specified in the command line, or when the > Target implements getOperationCost(unsigned Opcode, Type *Ty, Type *OpTy) > to return TCC_Expensive for operator types that are bigger than the default > target register size. > > > > ; ModuleID = 'main.c' > source_filename = "main.c" > target datalayout = > "e-m:e-p:16:16-i32:16-i64:16-f32:16-f64:16-a:8-n8:16-S16" > target triple = "msp...

On Sun, Sep 29, 2019 at 3:35 PM Joan Lluch via llvm-dev <llvm-dev at lists.llvm.org> wrote: > > Hi Sanjay, > > Actually, the CodeGenPrepare::optimizeSelectInst is not doing the best it could do in some circumstances: The case of “OptSize" for targets not supporting Select was already mentioned to be detrimental. > > For targets that actually have selects, but branches

...code that I posted before. This IR code, including the presence of expensive shifts ( %a.lobit = lshr i32 %a, 31) is generated when -mllvm -phi-node-folding-threshold=1 is specified in the command line, or when the Target implements getOperationCost(unsigned Opcode, Type *Ty, Type *OpTy) to return TCC_Expensive for operator types that are bigger than the default target register size. >>> >>> >>> >>> ; ModuleID = 'main.c' >>> source_filename = "main.c" >>> target datalayout = "e-m:e-p:16:16-i32:16-i64:16-f32:16-f64:16-a:8-n8:16...

...code that I posted before. This IR code, including the presence of expensive shifts ( %a.lobit = lshr i32 %a, 31) is generated when -mllvm -phi-node-folding-threshold=1 is specified in the command line, or when the Target implements getOperationCost(unsigned Opcode, Type *Ty, Type *OpTy) to return TCC_Expensive for operator types that are bigger than the default target register size. >>>> >>>> >>>> >>>> ; ModuleID = 'main.c' >>>> source_filename = "main.c" >>>> target datalayout = "e-m:e-p:16:16-i32:16-i64:16...