[llvm] 211596c - [VPlan] Support extracting lanes for defs managed in VPTransformState.

[Florian Hahn via llvm-commits]

Author: Florian Hahn
Date: 2020-06-03T12:14:16+01:00
New Revision: 211596c94e92d179e095734b23899d877c8fc3e5

URL: https://github.com/llvm/llvm-project/commit/211596c94e92d179e095734b23899d877c8fc3e5
DIFF: https://github.com/llvm/llvm-project/commit/211596c94e92d179e095734b23899d877c8fc3e5.diff

LOG: [VPlan] Support extracting lanes for defs managed in VPTransformState.

Currently extracting a lane for a VPValue def is not supported, if it is
managed directly by VPTransformState (e.g. because it is created by a
VPInstruction or an external VPValue def).

For now, simply extract the requested lane. In the future, we should
also cache the extracted scalar values, similar to LV.

Reviewers: Ayal, rengolin, gilr, SjoerdMeijer

Reviewed By: SjoerdMeijer

Differential Revision: https://reviews.llvm.org/D80787

Added: 
    

Modified: 
    llvm/lib/Transforms/Vectorize/VPlan.h

Removed: 
    


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diff  --git a/llvm/lib/Transforms/Vectorize/VPlan.h b/llvm/lib/Transforms/Vectorize/VPlan.h
index 1d07d5cff8a3..c3097e1e1f14 100644
--- a/llvm/lib/Transforms/Vectorize/VPlan.h
+++ b/llvm/lib/Transforms/Vectorize/VPlan.h
@@ -270,10 +270,20 @@ struct VPTransformState {
     return Callback.getOrCreateVectorValues(VPValue2Value[Def], Part);
   }
 
-  /// Get the generated Value for a given VPValue and given Part and Lane. Note
-  /// that as per-lane Defs are still created by ILV and managed in its ValueMap
-  /// this method currently just delegates the call to ILV.
+  /// Get the generated Value for a given VPValue and given Part and Lane.
   Value *get(VPValue *Def, const VPIteration &Instance) {
+    // If the Def is managed directly by VPTransformState, extract the lane from
+    // the relevant part. Note that currently only VPInstructions and external
+    // defs are managed by VPTransformState. Other Defs are still created by ILV
+    // and managed in its ValueMap. For those this method currently just
+    // delegates the call to ILV below.
+    if (Data.PerPartOutput.count(Def)) {
+      auto *VecPart = Data.PerPartOutput[Def][Instance.Part];
+      // TODO: Cache created scalar values.
+      return Builder.CreateExtractElement(VecPart,
+                                          Builder.getInt32(Instance.Lane));
+    }
+
     return Callback.getOrCreateScalarValue(VPValue2Value[Def], Instance);
   }