AMDGPU: Fix counting debug instructions in execz skip threshold

Author: arsenm

llvm/lib/Target/AMDGPU/SIPreEmitPeephole.cpp

@@ -320,6 +320,9 @@ bool SIPreEmitPeephole::mustRetainExeczBranch(
       if (MI.isConditionalBranch())
         return true;
 
+      if (MI.isMetaInstruction())
+        continue;
+
       if (TII->hasUnwantedEffectsWhenEXECEmpty(MI))
         return true;
 

llvm/test/CodeGen/AMDGPU/insert-skips-ignored-insts.mir

@@ -2,7 +2,6 @@
 
 ---
 
-# FIXME: RemoveShortExecBranches should not count dbg_value instructions.
 # CHECK-LABEL: name: no_count_dbg_value
 # CHECK: $vgpr1 = V_MOV_B32_e32 7, implicit $exec
 # CHECK-NOT: S_CBRANCH_EXECZ
@@ -18,6 +17,11 @@ body: |
     successors: %bb.2
     $vgpr0 = V_MOV_B32_e32 0, implicit $exec
     DBG_VALUE
+    DBG_VALUE
+    DBG_VALUE
+    DBG_VALUE
+    DBG_VALUE
+    DBG_VALUE
 
   bb.2:
     $vgpr0 = V_MOV_B32_e32 1, implicit $exec