[llvm] [AArch64][NEON][SVE] Lower mixed sign/zero extended partial reductions to usdot (PR #107566)
Sam Tebbs via llvm-commits
llvm-commits at lists.llvm.org
Tue Sep 17 02:38:56 PDT 2024
================
@@ -21824,37 +21830,54 @@ SDValue tryLowerPartialReductionToDot(SDNode *N,
auto ExtA = MulOp->getOperand(0);
auto ExtB = MulOp->getOperand(1);
- bool IsSExt = ExtA->getOpcode() == ISD::SIGN_EXTEND;
- bool IsZExt = ExtA->getOpcode() == ISD::ZERO_EXTEND;
- if (ExtA->getOpcode() != ExtB->getOpcode() || (!IsSExt && !IsZExt))
+
+ bool AIsSExt = ExtA->getOpcode() == ISD::SIGN_EXTEND;
+ bool AIsZExt = ExtA->getOpcode() == ISD::ZERO_EXTEND;
+ bool BIsSExt = ExtB->getOpcode() == ISD::SIGN_EXTEND;
+ bool BIsZExt = ExtB->getOpcode() == ISD::ZERO_EXTEND;
+ if (!(AIsSExt || AIsZExt) || !(BIsSExt || BIsZExt))
return SDValue();
auto A = ExtA->getOperand(0);
auto B = ExtB->getOperand(0);
if (A.getValueType() != B.getValueType())
return SDValue();
+ EVT ReducedType = N->getValueType(0);
+ EVT MulSrcType = A.getValueType();
+
+ // Dot products operate on chunks of four elements so there must be four times
+ // as many elements in the wide type
+ if (!(ReducedType == MVT::nxv4i32 && MulSrcType == MVT::nxv16i8) &&
+ !(ReducedType == MVT::nxv2i64 && MulSrcType == MVT::nxv8i16) &&
+ !(ReducedType == MVT::v4i32 && MulSrcType == MVT::v16i8) &&
+ !(ReducedType == MVT::v2i32 && MulSrcType == MVT::v8i8))
+ return SDValue();
+
+ // If the extensions are mixed, we should lower it to a usdot instead
unsigned Opcode = 0;
+ if (AIsZExt != BIsZExt) {
+ if (!Subtarget->hasMatMulInt8())
+ return SDValue();
+
+ bool Scalable = N->getValueType(0).isScalableVT();
+ // There's no nxv2i64 version of usdot
+ if (Scalable && ReducedType != MVT::nxv4i32)
+ return SDValue();
- if (IsSExt)
+ Opcode = AArch64ISD::USDOT;
+ // USDOT expects the first operand to be unsigned, so swap the operands if
+ // the first is signed and the second is unsigned
+ if (AIsSExt && BIsZExt)
----------------
SamTebbs33 wrote:
Done.
https://github.com/llvm/llvm-project/pull/107566
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