[PATCH] D107448: {DebugInfo][LoopStrengthReduction] Don't cache dbg.value that are already undef

[Chris Jackson via Phabricator via llvm-commits]

chrisjackson updated this revision to Diff 364180.
chrisjackson added a comment.

Update patch to apply on top of https://github.com/llvm/llvm-project/commit/914066fe38a93c004b742a696ec337701eb738ec


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D107448/new/

https://reviews.llvm.org/D107448

Files:
  llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
  llvm/test/Transforms/LoopStrengthReduce/pr51329.ll


Index: llvm/test/Transforms/LoopStrengthReduce/pr51329.ll
===================================================================
--- llvm/test/Transforms/LoopStrengthReduce/pr51329.ll
+++ llvm/test/Transforms/LoopStrengthReduce/pr51329.ll
@@ -2,7 +2,10 @@
 ;
 ; Test that LSR SCEV-based salvaging does not crash when translating SCEVs
 ; that contain integers with binary representations greater than 64-bits. 
+; Also show that no salvaging attempt is made for dbg.value that are undef
+; pre-LSR.
 ;
+; CHECK: call void @llvm.dbg.value(metadata i64 undef, metadata !{{[0-9]+}}, metadata !DIExpression(DW_OP_plus_uconst, 228, DW_OP_stack_value))
 ; CHECK: call void @llvm.dbg.value(metadata i64 %var2, metadata !{{[0-9]+}}, metadata !DIExpression(DW_OP_plus_uconst, 228, DW_OP_stack_value))
 
 
@@ -23,6 +26,7 @@
 
 Label_d0:                                         ; preds = %Label_d0, %init
   %var3 = phi i64 [ %var2, %init ], [ %var4, %Label_d0 ]
+  call void @llvm.dbg.value(metadata i64 undef, metadata !11, metadata !DIExpression(DW_OP_plus_uconst, 228, DW_OP_stack_value)), !dbg !12
   call void @llvm.dbg.value(metadata i64 %var2, metadata !11, metadata !DIExpression(DW_OP_plus_uconst, 228, DW_OP_stack_value)), !dbg !12
   %var4 = add i64 %var3, -1
   %var5 = icmp eq i64 %var4, 0
Index: llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
===================================================================
--- llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
+++ llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
@@ -6222,6 +6222,9 @@
       if (!DVI)
         continue;
 
+      if (DVI->isUndef())
+        continue;
+
       if (DVI->hasArgList())
         continue;
 


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