[CostModel/RISCV] Fix costs of vector [l](lrint|lround) #146058
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@llvm/pr-subscribers-backend-risc-v @llvm/pr-subscribers-llvm-analysis Author: Ramkumar Ramachandra (artagnon) ChangesTake the actual instruction cost into account, and don't fallthrough to code that doesn't apply to [l]lrint. Full diff: https://github.com/llvm/llvm-project/pull/146058.diff 2 Files Affected:
diff --git a/llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp b/llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp
index 67a51c12b508e..56773372da905 100644
--- a/llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp
+++ b/llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp
@@ -1191,9 +1191,6 @@ static const CostTblEntry VectorIntrinsicCostTable[]{
{Intrinsic::roundeven, MVT::f64, 9},
{Intrinsic::rint, MVT::f32, 7},
{Intrinsic::rint, MVT::f64, 7},
- {Intrinsic::lrint, MVT::i32, 1},
- {Intrinsic::lrint, MVT::i64, 1},
- {Intrinsic::llrint, MVT::i64, 1},
{Intrinsic::nearbyint, MVT::f32, 9},
{Intrinsic::nearbyint, MVT::f64, 9},
{Intrinsic::bswap, MVT::i16, 3},
@@ -1261,12 +1258,17 @@ RISCVTTIImpl::getIntrinsicInstrCost(const IntrinsicCostAttributes &ICA,
auto *RetTy = ICA.getReturnType();
switch (ICA.getID()) {
case Intrinsic::lrint:
- case Intrinsic::llrint:
+ case Intrinsic::llrint: {
// We can't currently lower half or bfloat vector lrint/llrint.
if (auto *VecTy = dyn_cast<VectorType>(ICA.getArgTypes()[0]);
VecTy && VecTy->getElementType()->is16bitFPTy())
return InstructionCost::getInvalid();
- [[fallthrough]];
+ auto LT = getTypeLegalizationCost(RetTy);
+ if (ST->hasVInstructions() && LT.second.isVector())
+ return LT.first *
+ getRISCVInstructionCost(RISCV::VFCVT_X_F_V, LT.second, CostKind);
+ break;
+ }
case Intrinsic::ceil:
case Intrinsic::floor:
case Intrinsic::trunc:
diff --git a/llvm/test/Analysis/CostModel/RISCV/fround.ll b/llvm/test/Analysis/CostModel/RISCV/fround.ll
index a0818d487d151..57b40201662e5 100644
--- a/llvm/test/Analysis/CostModel/RISCV/fround.ll
+++ b/llvm/test/Analysis/CostModel/RISCV/fround.ll
@@ -436,23 +436,23 @@ define void @lrint() {
; CHECK-NEXT: Cost Model: Invalid cost for instruction: %10 = call <vscale x 16 x i64> @llvm.lrint.nxv16i64.nxv16bf16(<vscale x 16 x bfloat> undef)
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %11 = call i64 @llvm.lrint.i64.f32(float undef)
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %12 = call <2 x i64> @llvm.lrint.v2i64.v2f32(<2 x float> undef)
-; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %13 = call <4 x i64> @llvm.lrint.v4i64.v4f32(<4 x float> undef)
-; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %14 = call <8 x i64> @llvm.lrint.v8i64.v8f32(<8 x float> undef)
-; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %15 = call <16 x i64> @llvm.lrint.v16i64.v16f32(<16 x float> undef)
+; CHECK-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %13 = call <4 x i64> @llvm.lrint.v4i64.v4f32(<4 x float> undef)
+; CHECK-NEXT: Cost Model: Found an estimated cost of 4 for instruction: %14 = call <8 x i64> @llvm.lrint.v8i64.v8f32(<8 x float> undef)
+; CHECK-NEXT: Cost Model: Found an estimated cost of 8 for instruction: %15 = call <16 x i64> @llvm.lrint.v16i64.v16f32(<16 x float> undef)
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %16 = call <vscale x 1 x i64> @llvm.lrint.nxv1i64.nxv1f32(<vscale x 1 x float> undef)
-; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %17 = call <vscale x 2 x i64> @llvm.lrint.nxv2i64.nxv2f32(<vscale x 2 x float> undef)
-; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %18 = call <vscale x 4 x i64> @llvm.lrint.nxv4i64.nxv4f32(<vscale x 4 x float> undef)
-; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %19 = call <vscale x 8 x i64> @llvm.lrint.nxv8i64.nxv8f32(<vscale x 8 x float> undef)
-; CHECK-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %20 = call <vscale x 16 x i64> @llvm.lrint.nxv16i64.nxv16f32(<vscale x 16 x float> undef)
+; CHECK-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %17 = call <vscale x 2 x i64> @llvm.lrint.nxv2i64.nxv2f32(<vscale x 2 x float> undef)
+; CHECK-NEXT: Cost Model: Found an estimated cost of 4 for instruction: %18 = call <vscale x 4 x i64> @llvm.lrint.nxv4i64.nxv4f32(<vscale x 4 x float> undef)
+; CHECK-NEXT: Cost Model: Found an estimated cost of 8 for instruction: %19 = call <vscale x 8 x i64> @llvm.lrint.nxv8i64.nxv8f32(<vscale x 8 x float> undef)
+; CHECK-NEXT: Cost Model: Found an estimated cost of 16 for instruction: %20 = call <vscale x 16 x i64> @llvm.lrint.nxv16i64.nxv16f32(<vscale x 16 x float> undef)
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %21 = call i64 @llvm.lrint.i64.f64(double undef)
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %22 = call <2 x i64> @llvm.lrint.v2i64.v2f64(<2 x double> undef)
-; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %23 = call <4 x i64> @llvm.lrint.v4i64.v4f64(<4 x double> undef)
-; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %24 = call <8 x i64> @llvm.lrint.v8i64.v8f64(<8 x double> undef)
-; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %25 = call <16 x i64> @llvm.lrint.v16i64.v16f64(<16 x double> undef)
+; CHECK-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %23 = call <4 x i64> @llvm.lrint.v4i64.v4f64(<4 x double> undef)
+; CHECK-NEXT: Cost Model: Found an estimated cost of 4 for instruction: %24 = call <8 x i64> @llvm.lrint.v8i64.v8f64(<8 x double> undef)
+; CHECK-NEXT: Cost Model: Found an estimated cost of 8 for instruction: %25 = call <16 x i64> @llvm.lrint.v16i64.v16f64(<16 x double> undef)
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %26 = call <vscale x 1 x i64> @llvm.lrint.nxv1i64.nxv1f64(<vscale x 1 x double> undef)
-; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %27 = call <vscale x 2 x i64> @llvm.lrint.nxv2i64.nxv2f64(<vscale x 2 x double> undef)
-; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %28 = call <vscale x 4 x i64> @llvm.lrint.nxv4i64.nxv4f64(<vscale x 4 x double> undef)
-; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %29 = call <vscale x 8 x i64> @llvm.lrint.nxv8i64.nxv8f64(<vscale x 8 x double> undef)
+; CHECK-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %27 = call <vscale x 2 x i64> @llvm.lrint.nxv2i64.nxv2f64(<vscale x 2 x double> undef)
+; CHECK-NEXT: Cost Model: Found an estimated cost of 4 for instruction: %28 = call <vscale x 4 x i64> @llvm.lrint.nxv4i64.nxv4f64(<vscale x 4 x double> undef)
+; CHECK-NEXT: Cost Model: Found an estimated cost of 8 for instruction: %29 = call <vscale x 8 x i64> @llvm.lrint.nxv8i64.nxv8f64(<vscale x 8 x double> undef)
; CHECK-NEXT: Cost Model: Found an estimated cost of 0 for instruction: ret void
;
call i64 @llvm.lrint.i64.bf16(bfloat undef)
@@ -528,23 +528,23 @@ define void @llrint() {
; CHECK-NEXT: Cost Model: Invalid cost for instruction: %10 = call <vscale x 16 x i64> @llvm.llrint.nxv16i64.nxv16bf16(<vscale x 16 x bfloat> undef)
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %11 = call i64 @llvm.llrint.i64.f32(float undef)
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %12 = call <2 x i64> @llvm.llrint.v2i64.v2f32(<2 x float> undef)
-; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %13 = call <4 x i64> @llvm.llrint.v4i64.v4f32(<4 x float> undef)
-; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %14 = call <8 x i64> @llvm.llrint.v8i64.v8f32(<8 x float> undef)
-; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %15 = call <16 x i64> @llvm.llrint.v16i64.v16f32(<16 x float> undef)
+; CHECK-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %13 = call <4 x i64> @llvm.llrint.v4i64.v4f32(<4 x float> undef)
+; CHECK-NEXT: Cost Model: Found an estimated cost of 4 for instruction: %14 = call <8 x i64> @llvm.llrint.v8i64.v8f32(<8 x float> undef)
+; CHECK-NEXT: Cost Model: Found an estimated cost of 8 for instruction: %15 = call <16 x i64> @llvm.llrint.v16i64.v16f32(<16 x float> undef)
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %16 = call <vscale x 1 x i64> @llvm.llrint.nxv1i64.nxv1f32(<vscale x 1 x float> undef)
-; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %17 = call <vscale x 2 x i64> @llvm.llrint.nxv2i64.nxv2f32(<vscale x 2 x float> undef)
-; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %18 = call <vscale x 4 x i64> @llvm.llrint.nxv4i64.nxv4f32(<vscale x 4 x float> undef)
-; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %19 = call <vscale x 8 x i64> @llvm.llrint.nxv8i64.nxv8f32(<vscale x 8 x float> undef)
-; CHECK-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %20 = call <vscale x 16 x i64> @llvm.llrint.nxv16i64.nxv16f32(<vscale x 16 x float> undef)
+; CHECK-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %17 = call <vscale x 2 x i64> @llvm.llrint.nxv2i64.nxv2f32(<vscale x 2 x float> undef)
+; CHECK-NEXT: Cost Model: Found an estimated cost of 4 for instruction: %18 = call <vscale x 4 x i64> @llvm.llrint.nxv4i64.nxv4f32(<vscale x 4 x float> undef)
+; CHECK-NEXT: Cost Model: Found an estimated cost of 8 for instruction: %19 = call <vscale x 8 x i64> @llvm.llrint.nxv8i64.nxv8f32(<vscale x 8 x float> undef)
+; CHECK-NEXT: Cost Model: Found an estimated cost of 16 for instruction: %20 = call <vscale x 16 x i64> @llvm.llrint.nxv16i64.nxv16f32(<vscale x 16 x float> undef)
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %21 = call i64 @llvm.llrint.i64.f64(double undef)
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %22 = call <2 x i64> @llvm.llrint.v2i64.v2f64(<2 x double> undef)
-; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %23 = call <4 x i64> @llvm.llrint.v4i64.v4f64(<4 x double> undef)
-; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %24 = call <8 x i64> @llvm.llrint.v8i64.v8f64(<8 x double> undef)
-; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %25 = call <16 x i64> @llvm.llrint.v16i64.v16f64(<16 x double> undef)
+; CHECK-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %23 = call <4 x i64> @llvm.llrint.v4i64.v4f64(<4 x double> undef)
+; CHECK-NEXT: Cost Model: Found an estimated cost of 4 for instruction: %24 = call <8 x i64> @llvm.llrint.v8i64.v8f64(<8 x double> undef)
+; CHECK-NEXT: Cost Model: Found an estimated cost of 8 for instruction: %25 = call <16 x i64> @llvm.llrint.v16i64.v16f64(<16 x double> undef)
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %26 = call <vscale x 1 x i64> @llvm.llrint.nxv1i64.nxv1f64(<vscale x 1 x double> undef)
-; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %27 = call <vscale x 2 x i64> @llvm.llrint.nxv2i64.nxv2f64(<vscale x 2 x double> undef)
-; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %28 = call <vscale x 4 x i64> @llvm.llrint.nxv4i64.nxv4f64(<vscale x 4 x double> undef)
-; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %29 = call <vscale x 8 x i64> @llvm.llrint.nxv8i64.nxv8f64(<vscale x 8 x double> undef)
+; CHECK-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %27 = call <vscale x 2 x i64> @llvm.llrint.nxv2i64.nxv2f64(<vscale x 2 x double> undef)
+; CHECK-NEXT: Cost Model: Found an estimated cost of 4 for instruction: %28 = call <vscale x 4 x i64> @llvm.llrint.nxv4i64.nxv4f64(<vscale x 4 x double> undef)
+; CHECK-NEXT: Cost Model: Found an estimated cost of 8 for instruction: %29 = call <vscale x 8 x i64> @llvm.llrint.nxv8i64.nxv8f64(<vscale x 8 x double> undef)
; CHECK-NEXT: Cost Model: Found an estimated cost of 0 for instruction: ret void
;
call i64 @llvm.llrint.i64.bf16(bfloat undef)
|
topperc
reviewed
Jul 10, 2025
topperc
reviewed
Jul 10, 2025
artagnon
changed the title
artagnon
changed the title
topperc
reviewed
Jul 10, 2025
Take the actual instruction cost into account, and don't fallthrough to code that doesn't apply to [l]lrint.
|
Sorry about the delay, but I think all the issues should be fixed now. |
lukel97
reviewed
Jul 29, 2025
|
This triggered a buildbot failure, which is fixed in #151210. |
topperc
reviewed
Jul 29, 2025
| ; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %26 = call <vscale x 1 x i32> @llvm.lrint.nxv1i32.nxv1f64(<vscale x 1 x double> poison) | ||
| ; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %27 = call <vscale x 2 x i32> @llvm.lrint.nxv2i32.nxv2f64(<vscale x 2 x double> poison) | ||
| ; CHECK-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %28 = call <vscale x 4 x i32> @llvm.lrint.nxv4i32.nxv4f64(<vscale x 4 x double> poison) | ||
| ; CHECK-NEXT: Cost Model: Found an estimated cost of 4 for instruction: %29 = call <vscale x 8 x i32> @llvm.lrint.nxv8i32.nxv8f64(<vscale x 8 x double> poison) |
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This should maybe be 8, nxv8f64 is LMUL=8 nxv8i32 is LMUL=4. Should narrowing operations run at source LMUL or destination LMUL?
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Oh, this is a good question that I hadn't thought about. I think narrowing operations are a special case which should return std::max(SrcLT.first, LT.first) * getRISCVInstructionCost(Ops, SrcLT.second, CostKind)? I will work on a follow-up.
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Oh, this is a good question that I hadn't thought about. I think narrowing operations are a special case which should return
std::max(SrcLT.first, LT.first) * getRISCVInstructionCost(Ops, SrcLT.second, CostKind)? I will work on a follow-up.
Ugh, wait: maybe SrcLT.first * getRISCVInstructionCost(Ops, LT.second, CostKind), and the std::max is wrong?
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Oh, this is a good question that I hadn't thought about. I think narrowing operations are a special case which should return
std::max(SrcLT.first, LT.first) * getRISCVInstructionCost(Ops, SrcLT.second, CostKind)? I will work on a follow-up.Ugh, wait: maybe SrcLT.second.changeVectorElementType([element type of LT.second])?
SrcLT could have more elements that LT in that case so I don't think that's right. So using the element type from LT and element count from SrcLT could create an LMUL=16 type.
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I think the simplest thing to do is just to check which is the larger type and use the corresponding one e.g.
if (SrcEltSz > DstEltSize)
return SrcLT.first * getRISCVInstructionCost(Ops, SrcLT.second, CostKind);
else
return LT.first * getRISCVInstructionCost(Ops, LT.second, CostKind);
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Take the actual instruction cost into account, and don't fallthrough to code that doesn't apply to [l]lrint. Also strip invalid costs for [b]f16, as a companion to #146507, and unify it with [l]lround costs as a companion to #147713.