From c0edb8f5cf2f19496e44f59dce33d3e5695f5bf6 Mon Sep 17 00:00:00 2001
From: Matt Arsenault <Matthew.Arsenault@amd.com>
Date: Fri, 7 Jun 2019 00:14:55 +0000
Subject: [PATCH] AMDGPU: Don't count mask branch pseudo towards skip threshold

llvm-svn: 362761
---
 llvm/lib/Target/AMDGPU/SIInsertSkips.cpp      | 18 +++----
 .../AMDGPU/insert-skips-ignored-insts.mir     | 54 +++++++++++++++++++
 2 files changed, 62 insertions(+), 10 deletions(-)
 create mode 100644 llvm/test/CodeGen/AMDGPU/insert-skips-ignored-insts.mir

diff --git a/llvm/lib/Target/AMDGPU/SIInsertSkips.cpp b/llvm/lib/Target/AMDGPU/SIInsertSkips.cpp
index 507c686e1cf2..759e28e431fe 100644
--- a/llvm/lib/Target/AMDGPU/SIInsertSkips.cpp
+++ b/llvm/lib/Target/AMDGPU/SIInsertSkips.cpp
@@ -92,15 +92,13 @@ INITIALIZE_PASS(SIInsertSkips, DEBUG_TYPE,
 
 char &llvm::SIInsertSkipsPassID = SIInsertSkips::ID;
 
-static bool opcodeEmitsNoInsts(unsigned Opc) {
-  switch (Opc) {
-  case TargetOpcode::IMPLICIT_DEF:
-  case TargetOpcode::KILL:
-  case TargetOpcode::BUNDLE:
-  case TargetOpcode::CFI_INSTRUCTION:
-  case TargetOpcode::EH_LABEL:
-  case TargetOpcode::GC_LABEL:
-  case TargetOpcode::DBG_VALUE:
+static bool opcodeEmitsNoInsts(const MachineInstr &MI) {
+  if (MI.isMetaInstruction())
+    return true;
+
+  // Handle target specific opcodes.
+  switch (MI.getOpcode()) {
+  case AMDGPU::SI_MASK_BRANCH:
     return true;
   default:
     return false;
@@ -118,7 +116,7 @@ bool SIInsertSkips::shouldSkip(const MachineBasicBlock &From,
 
     for (MachineBasicBlock::const_iterator I = MBB.begin(), E = MBB.end();
          NumInstr < SkipThreshold && I != E; ++I) {
-      if (opcodeEmitsNoInsts(I->getOpcode()))
+      if (opcodeEmitsNoInsts(*I))
         continue;
 
       // FIXME: Since this is required for correctness, this should be inserted
diff --git a/llvm/test/CodeGen/AMDGPU/insert-skips-ignored-insts.mir b/llvm/test/CodeGen/AMDGPU/insert-skips-ignored-insts.mir
new file mode 100644
index 000000000000..7da59df5d80c
--- /dev/null
+++ b/llvm/test/CodeGen/AMDGPU/insert-skips-ignored-insts.mir
@@ -0,0 +1,54 @@
+# RUN: llc -mtriple=amdgcn-amd-amdhsa -run-pass si-insert-skips -amdgpu-skip-threshold=2 %s -o - | FileCheck %s
+
+---
+
+# CHECK-LABEL: name: no_count_mask_branch_pseudo
+# CHECK: $vgpr1 = V_MOV_B32_e32 7, implicit $exec
+# CHECK-NEXT: SI_MASK_BRANCH
+# CHECK-NOT: S_CBRANCH_EXECZ
+name: no_count_mask_branch_pseudo
+body: |
+  bb.0:
+    successors: %bb.1
+
+    $vgpr1 = V_MOV_B32_e32 7, implicit $exec
+    SI_MASK_BRANCH %bb.2, implicit $exec
+
+  bb.1:
+    successors: %bb.2
+    $vgpr0 = V_MOV_B32_e32 0, implicit $exec
+    SI_MASK_BRANCH %bb.3, implicit $exec
+
+  bb.2:
+    $vgpr0 = V_MOV_B32_e32 1, implicit $exec
+
+  bb.3:
+    S_ENDPGM 0
+...
+
+---
+
+# CHECK-LABEL: name: no_count_dbg_value
+# CHECK: $vgpr1 = V_MOV_B32_e32 7, implicit $exec
+# CHECK-NEXT: SI_MASK_BRANCH
+# CHECK-NOT: S_CBRANCH_EXECZ
+name: no_count_dbg_value
+body: |
+  bb.0:
+    successors: %bb.1
+
+    $vgpr1 = V_MOV_B32_e32 7, implicit $exec
+    SI_MASK_BRANCH %bb.2, implicit $exec
+
+  bb.1:
+    successors: %bb.2
+    $vgpr0 = V_MOV_B32_e32 0, implicit $exec
+    DBG_VALUE
+
+  bb.2:
+    $vgpr0 = V_MOV_B32_e32 1, implicit $exec
+
+  bb.3:
+    S_ENDPGM 0
+...
+
-- 
2.34.1