[PATCH] D76881: [AMDGPU] Skip CFIInstructions in SIInsertWaitcnts

[Scott Linder via Phabricator via llvm-commits]

scott.linder updated this revision to Diff 252965.
scott.linder added a comment.

Add a test


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D76881/new/

https://reviews.llvm.org/D76881

Files:
  llvm/lib/Target/AMDGPU/SIInsertWaitcnts.cpp
  llvm/test/CodeGen/AMDGPU/waitcnt-skip-cfi.mir


Index: llvm/test/CodeGen/AMDGPU/waitcnt-skip-cfi.mir
===================================================================
--- /dev/null
+++ llvm/test/CodeGen/AMDGPU/waitcnt-skip-cfi.mir
@@ -0,0 +1,23 @@
+# RUN: llc -march=amdgcn -mcpu=gfx900 -run-pass si-insert-waitcnts  %s -o - | FileCheck %s
+
+--- |
+
+  define void @skip_cfi() {
+    ret void
+  }
+
+...
+---
+
+# Ensure we insert waitcnts after any CFI at the start of non-kernel functions
+
+# CHECK-LABEL: name: skip_cfi{{$}}
+# CHECK: frame-setup CFI_INSTRUCTION
+# CHECK: S_WAITCNT
+
+name: skip_cfi
+machineFunctionInfo:
+body: |
+  bb.0:
+    frame-setup CFI_INSTRUCTION undefined $sgpr0
+...
Index: llvm/lib/Target/AMDGPU/SIInsertWaitcnts.cpp
===================================================================
--- llvm/lib/Target/AMDGPU/SIInsertWaitcnts.cpp
+++ llvm/lib/Target/AMDGPU/SIInsertWaitcnts.cpp
@@ -1640,13 +1640,15 @@
     // TODO: Could insert earlier and schedule more liberally with operations
     // that only use caller preserved registers.
     MachineBasicBlock &EntryBB = MF.front();
+    MachineBasicBlock::iterator I = EntryBB.begin();
+    for (MachineBasicBlock::iterator E = EntryBB.end();
+         I != E && (I->isPHI() || I->isCFIInstruction()); ++I)
+      ;
+    BuildMI(EntryBB, I, DebugLoc(), TII->get(AMDGPU::S_WAITCNT)).addImm(0);
     if (ST->hasVscnt())
-      BuildMI(EntryBB, EntryBB.getFirstNonPHI(), DebugLoc(),
-              TII->get(AMDGPU::S_WAITCNT_VSCNT))
-      .addReg(AMDGPU::SGPR_NULL, RegState::Undef)
-      .addImm(0);
-    BuildMI(EntryBB, EntryBB.getFirstNonPHI(), DebugLoc(), TII->get(AMDGPU::S_WAITCNT))
-      .addImm(0);
+      BuildMI(EntryBB, I, DebugLoc(), TII->get(AMDGPU::S_WAITCNT_VSCNT))
+          .addReg(AMDGPU::SGPR_NULL, RegState::Undef)
+          .addImm(0);
 
     Modified = true;
   }


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