[AMDGPU][WaveTransform] Separating SiOptimizeExecMaskingPreRA pass usage for both pipelines. (#422)

We enable the SIOptimizeSexecMaskingPreRA pass just before SGPR
allocation as planned for waveTransform pipeline, while reverting back
to its orginal invocation in the default pipeline.

It is the continuation work on #412 .

Author: vg0204

llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp

@@ -1675,6 +1675,9 @@ void GCNPassConfig::addOptimizedRegAlloc() {
   // instructions that cause scheduling barriers.
   insertPass(&MachineSchedulerID, &SIWholeQuadModeID);
 
+  if (!LateWaveTransform && OptExecMaskPreRA)
+    insertPass(&MachineSchedulerID, &SIOptimizeExecMaskingPreRAID);
+
   // This is not an essential optimization and it has a noticeable impact on
   // compilation time, so we only enable it from O2.
   if (TM->getOptLevel() > CodeGenOptLevel::Less)
@@ -1853,13 +1856,14 @@ bool GCNPassConfig::addRegAssignAndRewriteOptimized() {
     // allocations.
     //    addPass(&AMDGPUUpdateAllocatedVGPRLiveRangesID);
 
+    // Optimize EXEC-mask related instructions around SGPR register class.
+    if (OptExecMaskPreRA)
+      addPass(&SIOptimizeExecMaskingPreRAID);
+
     // Now we can perform register-coalescing on remaining copies,
     // mainly sgpr copies and wwm-vgpr copies.
     addPass(&RegisterCoalescerID);
   }
-
-  if (OptExecMaskPreRA)
-    addPass(&SIOptimizeExecMaskingPreRAID);
 
   addPass(createSGPRAllocPass(true));
 

llvm/test/CodeGen/AMDGPU/WaveTransform/wave-transform-llc-pipeline.ll

@@ -385,9 +385,9 @@
 ; GCN-O3-NEXT:        AMDGPU Control Flow Wave Transform
 ; GCN-O3-NEXT:        Slot index numbering
 ; GCN-O3-NEXT:        Live Interval Analysis
+; GCN-O3-NEXT:        SI optimize exec mask operations pre-RA
 ; GCN-O3-NEXT:        Machine Natural Loop Construction
 ; GCN-O3-NEXT:        Register Coalescer
-; GCN-O3-NEXT:        SI optimize exec mask operations pre-RA
 ; GCN-O3-NEXT:        Machine Block Frequency Analysis
 ; GCN-O3-NEXT:        Debug Variable Analysis
 ; GCN-O3-NEXT:        Live Stack Slot Analysis

llvm/test/CodeGen/AMDGPU/llc-pipeline.ll

@@ -352,8 +352,8 @@
 ; GCN-O1-NEXT:        Rewrite Partial Register Uses
 ; GCN-O1-NEXT:        Machine Instruction Scheduler
 ; GCN-O1-NEXT:        SI Whole Quad Mode
-; GCN-O1-NEXT:        AMDGPU Pre-RA Long Branch Reg
 ; GCN-O1-NEXT:        SI optimize exec mask operations pre-RA
+; GCN-O1-NEXT:        AMDGPU Pre-RA Long Branch Reg
 ; GCN-O1-NEXT:        Machine Natural Loop Construction
 ; GCN-O1-NEXT:        Machine Block Frequency Analysis
 ; GCN-O1-NEXT:        Debug Variable Analysis
@@ -665,8 +665,8 @@
 ; GCN-O1-OPTS-NEXT:        Machine Instruction Scheduler
 ; GCN-O1-OPTS-NEXT:        AMDGPU Pre-RA optimizations
 ; GCN-O1-OPTS-NEXT:        SI Whole Quad Mode
-; GCN-O1-OPTS-NEXT:        AMDGPU Pre-RA Long Branch Reg
 ; GCN-O1-OPTS-NEXT:        SI optimize exec mask operations pre-RA
+; GCN-O1-OPTS-NEXT:        AMDGPU Pre-RA Long Branch Reg
 ; GCN-O1-OPTS-NEXT:        Machine Natural Loop Construction
 ; GCN-O1-OPTS-NEXT:        Machine Block Frequency Analysis
 ; GCN-O1-OPTS-NEXT:        Debug Variable Analysis
@@ -983,9 +983,9 @@
 ; GCN-O2-NEXT:        Machine Instruction Scheduler
 ; GCN-O2-NEXT:        AMDGPU Pre-RA optimizations
 ; GCN-O2-NEXT:        SI Whole Quad Mode
+; GCN-O2-NEXT:        SI optimize exec mask operations pre-RA
 ; GCN-O2-NEXT:        SI Form memory clauses
 ; GCN-O2-NEXT:        AMDGPU Pre-RA Long Branch Reg
-; GCN-O2-NEXT:        SI optimize exec mask operations pre-RA
 ; GCN-O2-NEXT:        Machine Natural Loop Construction
 ; GCN-O2-NEXT:        Machine Block Frequency Analysis
 ; GCN-O2-NEXT:        Debug Variable Analysis
@@ -1315,9 +1315,9 @@
 ; GCN-O3-NEXT:        Machine Instruction Scheduler
 ; GCN-O3-NEXT:        AMDGPU Pre-RA optimizations
 ; GCN-O3-NEXT:        SI Whole Quad Mode
+; GCN-O3-NEXT:        SI optimize exec mask operations pre-RA
 ; GCN-O3-NEXT:        SI Form memory clauses
 ; GCN-O3-NEXT:        AMDGPU Pre-RA Long Branch Reg
-; GCN-O3-NEXT:        SI optimize exec mask operations pre-RA
 ; GCN-O3-NEXT:        Machine Natural Loop Construction
 ; GCN-O3-NEXT:        Machine Block Frequency Analysis
 ; GCN-O3-NEXT:        Debug Variable Analysis