[llvm] r231324 - Remove the conditional addition of the execution dependency fixing

[Owen Anderson]

So, I’m not sure I like the direction these changes are going.  For low-latency compilation use cases, every additional pass scheduled incurs non-trivial extra compilation time costs.  My uses, which fit that scenario, are specifically tuned *not* to schedule passes that are not needed for specific subtargets, even when they would be no-ops, and it would a significant regression compile-time regression for us to lose that capability.

—Owen

> On Mar 4, 2015, at 4:28 PM, Eric Christopher <echristo at gmail.com> wrote:
> 
> Author: echristo
> Date: Wed Mar  4 18:28:55 2015
> New Revision: 231324
> 
> URL: http://llvm.org/viewvc/llvm-project?rev=231324&view=rev
> Log:
> Remove the conditional addition of the execution dependency fixing
> pass from the ARM backend as the pass itself will detect any use
> of the appropriate register class.
> 
> Modified:
>    llvm/trunk/lib/Target/ARM/ARMTargetMachine.cpp
> 
> Modified: llvm/trunk/lib/Target/ARM/ARMTargetMachine.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMTargetMachine.cpp?rev=231324&r1=231323&r2=231324&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Target/ARM/ARMTargetMachine.cpp (original)
> +++ llvm/trunk/lib/Target/ARM/ARMTargetMachine.cpp Wed Mar  4 18:28:55 2015
> @@ -358,9 +358,7 @@ void ARMPassConfig::addPreRegAlloc() {
> void ARMPassConfig::addPreSched2() {
>   if (getOptLevel() != CodeGenOpt::None) {
>     addPass(createARMLoadStoreOptimizationPass());
> -
> -    if (getARMSubtarget().hasNEON())
> -      addPass(createExecutionDependencyFixPass(&ARM::DPRRegClass));
> +    addPass(createExecutionDependencyFixPass(&ARM::DPRRegClass));
>   }
> 
>   // Expand some pseudo instructions into multiple instructions to allow
> 
> 
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