[Mlir-commits] [mlir] [mlir][linalg] Support subtracting accumulation in partial reduction … (PR #214033)

[llvmlistbot at llvm.org]

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@@ -562,7 +584,12 @@ struct LinalgOpPartialReductionInterface
         return op->emitOpError("Failed to anaysis the reduction operation.");
 
       Operation *reductionOp = combinerOps[0];
-      std::optional<TypedAttr> identity = arith::getNeutralElement(reductionOp);
+      std::optional<TypedAttr> identity;
+      if (isSubtractingAccumulation(reductionOp,
+                                    linalgOp.getRegionOutputArgs()[initIdx]))
+        identity = b.getZeroAttr(reductionOp->getResult(0).getType());
+      else
+        identity = arith::getNeutralElement(reductionOp);
       if (!identity.has_value())
         return op->emitOpError(
             "Failed to get an identity value for the reduction operation.");
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pstarkcdpr wrote:

After the refactor in commit 4e221308f922b304fb4d8345005674e72cd82131, there's a factory that creates both the identity element and the merge function at the same time. So this failure now potentially encapsulates a bunch of possible errors, so was updated to `failed to determine how to split the reduction operation`

https://github.com/llvm/llvm-project/pull/214033