[PATCH] D102721: [CSSPGO] Avoid deleting probe instruction in FoldValueComparisonIntoPredecessors

[Lei Wang via Phabricator via llvm-commits]

wlei updated this revision to Diff 346325.
wlei added a comment.

Address Hongtao's feedback, add test case


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D102721/new/

https://reviews.llvm.org/D102721

Files:
  llvm/lib/Transforms/Utils/SimplifyCFG.cpp
  llvm/test/Transforms/SampleProfile/pseudo-probe-dangle3.ll


Index: llvm/test/Transforms/SampleProfile/pseudo-probe-dangle3.ll
===================================================================
--- /dev/null
+++ llvm/test/Transforms/SampleProfile/pseudo-probe-dangle3.ll
@@ -0,0 +1,37 @@
+; Test after FoldValueComparisonIntoPredecessors, one dangling probe is generated
+; RUN: opt -S -passes='pseudo-probe,simplifycfg' < %s | FileCheck %s
+
+
+; CHECK: if.end80:                                         ; preds = %if.end
+; CHECK-NEXT:   call void @llvm.pseudoprobe(i64 -2281696412744416103, i64 3, i32 0, i64 -1)
+; CHECK-NEXT:   call void @llvm.pseudoprobe(i64 -2281696412744416103, i64 4, i32 2, i64 -1)
+
+define dso_local i32 @readCBPandCoeffsFromNAL(i1 %c, i32 %x, i32 %y) local_unnamed_addr {
+;
+if.end:
+  br i1 %c, label %if.end80, label %if.then64
+
+if.then64:                                        ; preds = %if.end
+  ret i32 %y
+
+if.end80:                                         ; preds = %if.end
+  switch i32 %x, label %lor.lhs.false89 [
+  i32 10, label %if.end172237
+  i32 14, label %if.end172237
+  i32 9, label %if.end172
+  ]
+
+lor.lhs.false89:                                  ; preds = %lor.lhs.false89, %if.end80
+  %cmp91 = icmp eq i32 %x, 12
+  br i1 %cmp91, label %if.end172, label %lor.lhs.false89
+
+if.end172:                                        ; preds = %lor.lhs.false89, %if.end80
+  br label %if.end239
+
+if.end172237:                                     ; preds = %if.end80, %if.end80
+  br label %if.end239
+
+if.end239:                                        ; preds = %if.end172237, %if.end172
+  %cbp.0 = phi i32 [ 1, %if.end172237 ], [ 0, %if.end172 ]
+  ret i32 %cbp.0
+}
Index: llvm/lib/Transforms/Utils/SimplifyCFG.cpp
===================================================================
--- llvm/lib/Transforms/Utils/SimplifyCFG.cpp
+++ llvm/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -1325,6 +1325,10 @@
     DTU->applyUpdates(Updates);
   }
 
+  // Here the BB is not a dead block but folded into its predecessors, so move
+  // the probe and mark it as dangling.
+  moveAndDanglePseudoProbes(BB, NewSI);
+
   ++NumFoldValueComparisonIntoPredecessors;
   return true;
 }


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