From d97bd5a03ba9dd319e5641074ffc4332555fb03b Mon Sep 17 00:00:00 2001
From: Matt Arsenault <Matthew.Arsenault@amd.com>
Date: Mon, 25 Jul 2016 19:48:29 +0000
Subject: [PATCH] AMDGPU: Make skip threshold an option

llvm-svn: 276680
---
 lib/Target/AMDGPU/SILowerControlFlow.cpp | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/lib/Target/AMDGPU/SILowerControlFlow.cpp b/lib/Target/AMDGPU/SILowerControlFlow.cpp
index b8ec59dc5c5..26ac5031803 100644
--- a/lib/Target/AMDGPU/SILowerControlFlow.cpp
+++ b/lib/Target/AMDGPU/SILowerControlFlow.cpp
@@ -66,12 +66,16 @@ using namespace llvm;
 
 namespace {
 
+static cl::opt<unsigned> SkipThresholdFlag(
+  "amdgpu-skip-threshold",
+  cl::desc("Number of instructions before jumping over divergent control flow"),
+  cl::init(12), cl::Hidden);
+
 class SILowerControlFlow : public MachineFunctionPass {
 private:
-  static const unsigned SkipThreshold = 12;
-
   const SIRegisterInfo *TRI;
   const SIInstrInfo *TII;
+  unsigned SkipThreshold;
 
   bool shouldSkip(MachineBasicBlock *From, MachineBasicBlock *To);
 
@@ -95,7 +99,7 @@ public:
   static char ID;
 
   SILowerControlFlow() :
-    MachineFunctionPass(ID), TRI(nullptr), TII(nullptr) { }
+    MachineFunctionPass(ID), TRI(nullptr), TII(nullptr), SkipThreshold(0) { }
 
   bool runOnMachineFunction(MachineFunction &MF) override;
 
@@ -405,6 +409,7 @@ bool SILowerControlFlow::runOnMachineFunction(MachineFunction &MF) {
   const SISubtarget &ST = MF.getSubtarget<SISubtarget>();
   TII = ST.getInstrInfo();
   TRI = &TII->getRegisterInfo();
+  SkipThreshold = SkipThresholdFlag;
 
   SIMachineFunctionInfo *MFI = MF.getInfo<SIMachineFunctionInfo>();