[llvm] 60b8b2b - [ARM] Add extra extend and trunc costs for cast instructions
David Green via llvm-commits
llvm-commits at lists.llvm.org
Mon Jul 6 03:33:19 PDT 2020
Author: David Green
Date: 2020-07-06T11:33:05+01:00
New Revision: 60b8b2beeab9b6a994108da6ea3ab225a9e7bd9a
URL: https://github.com/llvm/llvm-project/commit/60b8b2beeab9b6a994108da6ea3ab225a9e7bd9a
DIFF: https://github.com/llvm/llvm-project/commit/60b8b2beeab9b6a994108da6ea3ab225a9e7bd9a.diff
LOG: [ARM] Add extra extend and trunc costs for cast instructions
This expands the existing extend costs with a few extras for larger
types than legal, which will usually be split under MVE. It also adds
trunk support for the same thing. These should not have a large effect
on many things, but makes the costs explicit and keeps a certain balance
between the trunks and extends.
Differential Revision: https://reviews.llvm.org/D82457
Added:
Modified:
llvm/lib/Target/ARM/ARMTargetTransformInfo.cpp
llvm/test/Analysis/CostModel/ARM/cast_ldst.ll
Removed:
################################################################################
diff --git a/llvm/lib/Target/ARM/ARMTargetTransformInfo.cpp b/llvm/lib/Target/ARM/ARMTargetTransformInfo.cpp
index fa71a20d64f5..f3e1b5887bc0 100644
--- a/llvm/lib/Target/ARM/ARMTargetTransformInfo.cpp
+++ b/llvm/lib/Target/ARM/ARMTargetTransformInfo.cpp
@@ -228,12 +228,39 @@ int ARMTTIImpl::getCastInstrCost(unsigned Opcode, Type *Dst, Type *Src,
{ISD::ZERO_EXTEND, MVT::v4i32, MVT::v4i8, 0},
{ISD::SIGN_EXTEND, MVT::v8i16, MVT::v8i8, 0},
{ISD::ZERO_EXTEND, MVT::v8i16, MVT::v8i8, 0},
+ // The following extend from a legal type to an illegal type, so need to
+ // split the load. This introduced an extra load operation, but the
+ // extend is still "free".
+ {ISD::SIGN_EXTEND, MVT::v8i32, MVT::v8i16, 1},
+ {ISD::ZERO_EXTEND, MVT::v8i32, MVT::v8i16, 1},
+ {ISD::SIGN_EXTEND, MVT::v16i32, MVT::v16i8, 3},
+ {ISD::ZERO_EXTEND, MVT::v16i32, MVT::v16i8, 3},
+ {ISD::SIGN_EXTEND, MVT::v16i16, MVT::v16i8, 1},
+ {ISD::ZERO_EXTEND, MVT::v16i16, MVT::v16i8, 1},
};
if (SrcTy.isVector() && ST->hasMVEIntegerOps()) {
if (const auto *Entry =
ConvertCostTableLookup(MVELoadConversionTbl, ISD,
DstTy.getSimpleVT(), SrcTy.getSimpleVT()))
- return AdjustCost(Entry->Cost);
+ return AdjustCost(Entry->Cost * ST->getMVEVectorCostFactor());
+ }
+ }
+
+ // The truncate of a store is free. This is the mirror of extends above.
+ if (I && I->hasOneUse() && isa<StoreInst>(*I->user_begin())) {
+ static const TypeConversionCostTblEntry MVELoadConversionTbl[] = {
+ {ISD::TRUNCATE, MVT::v4i32, MVT::v4i16, 0},
+ {ISD::TRUNCATE, MVT::v4i32, MVT::v4i8, 0},
+ {ISD::TRUNCATE, MVT::v8i16, MVT::v8i8, 0},
+ {ISD::TRUNCATE, MVT::v8i32, MVT::v8i16, 1},
+ {ISD::TRUNCATE, MVT::v16i32, MVT::v16i8, 3},
+ {ISD::TRUNCATE, MVT::v16i16, MVT::v16i8, 1},
+ };
+ if (SrcTy.isVector() && ST->hasMVEIntegerOps()) {
+ if (const auto *Entry =
+ ConvertCostTableLookup(MVELoadConversionTbl, ISD, SrcTy.getSimpleVT(),
+ DstTy.getSimpleVT()))
+ return AdjustCost(Entry->Cost * ST->getMVEVectorCostFactor());
}
}
diff --git a/llvm/test/Analysis/CostModel/ARM/cast_ldst.ll b/llvm/test/Analysis/CostModel/ARM/cast_ldst.ll
index b22f8ed9e543..b9dc8a10a3c4 100644
--- a/llvm/test/Analysis/CostModel/ARM/cast_ldst.ll
+++ b/llvm/test/Analysis/CostModel/ARM/cast_ldst.ll
@@ -122,8 +122,8 @@ define i32 @load_extends() {
; CHECK-MVE-RECIP-NEXT: Cost Model: Found an estimated cost of 74 for instruction: %v8864u = zext <8 x i8> %loadv8i8 to <8 x i64>
; CHECK-MVE-RECIP-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %v16816s = sext <16 x i8> %loadv16i8 to <16 x i16>
; CHECK-MVE-RECIP-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %v16816u = zext <16 x i8> %loadv16i8 to <16 x i16>
-; CHECK-MVE-RECIP-NEXT: Cost Model: Found an estimated cost of 10 for instruction: %v16832s = sext <16 x i8> %loadv16i8 to <16 x i32>
-; CHECK-MVE-RECIP-NEXT: Cost Model: Found an estimated cost of 10 for instruction: %v16832u = zext <16 x i8> %loadv16i8 to <16 x i32>
+; CHECK-MVE-RECIP-NEXT: Cost Model: Found an estimated cost of 6 for instruction: %v16832s = sext <16 x i8> %loadv16i8 to <16 x i32>
+; CHECK-MVE-RECIP-NEXT: Cost Model: Found an estimated cost of 6 for instruction: %v16832u = zext <16 x i8> %loadv16i8 to <16 x i32>
; CHECK-MVE-RECIP-NEXT: Cost Model: Found an estimated cost of 1322 for instruction: %v16864s = sext <16 x i8> %loadv16i8 to <16 x i64>
; CHECK-MVE-RECIP-NEXT: Cost Model: Found an estimated cost of 298 for instruction: %v16864u = zext <16 x i8> %loadv16i8 to <16 x i64>
; CHECK-MVE-RECIP-NEXT: Cost Model: Found an estimated cost of 4 for instruction: %v21632s = sext <2 x i16> %loadv2i16 to <2 x i32>
@@ -758,7 +758,7 @@ define i32 @store_trunc() {
; CHECK-MVE-RECIP-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %v8832 = trunc <8 x i32> undef to <8 x i8>
; CHECK-MVE-RECIP-NEXT: Cost Model: Found an estimated cost of 10 for instruction: %v8864 = trunc <8 x i64> undef to <8 x i8>
; CHECK-MVE-RECIP-NEXT: Cost Model: Found an estimated cost of 2 for instruction: %v16816 = trunc <16 x i16> undef to <16 x i8>
-; CHECK-MVE-RECIP-NEXT: Cost Model: Found an estimated cost of 10 for instruction: %v16832 = trunc <16 x i32> undef to <16 x i8>
+; CHECK-MVE-RECIP-NEXT: Cost Model: Found an estimated cost of 6 for instruction: %v16832 = trunc <16 x i32> undef to <16 x i8>
; CHECK-MVE-RECIP-NEXT: Cost Model: Found an estimated cost of 42 for instruction: %v16864 = trunc <16 x i64> undef to <16 x i8>
; CHECK-MVE-RECIP-NEXT: Cost Model: Found an estimated cost of 0 for instruction: %v21632 = trunc <2 x i32> undef to <2 x i16>
; CHECK-MVE-RECIP-NEXT: Cost Model: Found an estimated cost of 0 for instruction: %v21664 = trunc <2 x i64> undef to <2 x i16>
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