[AMDGPU] Add CL option for max-ilp scheduler.

When compiling for multiple targets the scheduler that is selected via the
-misched option is applied globally. This patch adds a target CL option instead.

Reviewed By: rampitec

Differential Revision: https://reviews.llvm.org/D131022

Author: kerbowa

llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp

@@ -327,6 +327,11 @@ static cl::opt<bool> EnablePromoteKernelArguments(
     cl::desc("Enable promotion of flat kernel pointer arguments to global"),
     cl::Hidden, cl::init(true));
 
+static cl::opt<bool> EnableMaxIlpSchedStrategy(
+    "amdgpu-enable-max-ilp-scheduling-strategy",
+    cl::desc("Enable scheduling strategy to maximize ILP for a single wave."),
+    cl::Hidden, cl::init(false));
+
 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeAMDGPUTarget() {
   // Register the target
   RegisterTargetMachine<R600TargetMachine> X(getTheAMDGPUTarget());
@@ -1161,6 +1166,10 @@ ScheduleDAGInstrs *GCNPassConfig::createMachineScheduler(
   const GCNSubtarget &ST = C->MF->getSubtarget<GCNSubtarget>();
   if (ST.enableSIScheduler())
     return createSIMachineScheduler(C);
+
+  if (EnableMaxIlpSchedStrategy)
+    return createGCNMaxILPMachineScheduler(C);
+
   return createGCNMaxOccupancyMachineScheduler(C);
 }
 

llvm/test/CodeGen/AMDGPU/schedule-ilp.ll

@@ -1,5 +1,6 @@
 ; RUN: llc -march=amdgcn -mcpu=tonga -misched=gcn-iterative-ilp -verify-machineinstrs < %s | FileCheck %s
 ; RUN: llc -march=amdgcn -mcpu=tonga -misched=gcn-max-ilp -verify-machineinstrs < %s | FileCheck %s
+; RUN: llc -march=amdgcn -mcpu=tonga -amdgpu-enable-max-ilp-scheduling-strategy -verify-machineinstrs < %s | FileCheck %s
 
 ; CHECK: NumVgprs: {{[0-9][0-9][0-9]$}}