[llvm] [VPlan] Set debug location for VPReduction/VPWidenPHI/VPWidenIntrinsicRecipe. (PR #120054)

[Florian Hahn via llvm-commits]

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@@ -0,0 +1,33 @@
+; RUN: opt < %s -passes=debugify,loop-vectorize -force-vector-interleave=1 -force-vector-width=4 -prefer-inloop-reductions -S | FileCheck %s -check-prefix DEBUGLOC
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+
+; Testing the debug locations of the generated vector intstruction are same as
+; their scalar instruction.
+
+; DEBUGLOC-LABEL: define i32 @reduction_sum(
+define i32 @reduction_sum(ptr noalias nocapture %A, ptr noalias nocapture %B) {
+; DEBUGLOC: vector.body:
+; DEBUGLOC:   %[[VecLoad:.*]] = load <4 x i32>, ptr %2, align 4, !dbg ![[LoadLoc0:[0-9]+]]
+; DEBUGLOC:   %[[VecRed:.*]] = call i32 @llvm.vector.reduce.add.v4i32(<4 x i32> %wide.load), !dbg ![[RedLoc0:[0-9]+]]
+; DEBUGLOC: .lr.ph:
+; DEBUGLOC:   %l3 = load i32, ptr %l2, align 4, !dbg ![[LoadLoc0]]
+; DEBUGLOC:   %l7 = add i32 %sum.02, %l3, !dbg ![[RedLoc0]]
+entry:
+  br label %.lr.ph
+
+.lr.ph:                                           ; preds = %entry, %.lr.ph
+  %indvars.iv = phi i64 [ %indvars.iv.next, %.lr.ph ], [ 0, %entry ]
----------------
fhahn wrote:

```suggestion
  %iv = phi i64 [ 0, %entry ],  [ %v.next, %.lr.ph ]
```

https://github.com/llvm/llvm-project/pull/120054