[AArch64] Reduce vector insert/extract cost for Kryo

Differential Revision: http://reviews.llvm.org/D17379

llvm-svn: 261237

2 files changed, 28 insertions, 0 deletions

diff --git a/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp b/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
index bc044195856..08b89dc3c67 100644
--- a/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
+++ b/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
@@ -313,6 +313,8 @@ int AArch64TTIImpl::getVectorInstrCost(unsigned Opcode, Type *Val,
   }
 
   // All other insert/extracts cost this much.
+  if (ST->isKryo())
+    return 2;
   return 3;
 }
 
diff --git a/llvm/test/Analysis/CostModel/AArch64/kryo.ll b/llvm/test/Analysis/CostModel/AArch64/kryo.ll
new file mode 100644
index 00000000000..4b916a286ea
--- /dev/null
+++ b/llvm/test/Analysis/CostModel/AArch64/kryo.ll
@@ -0,0 +1,26 @@
+; RUN: opt < %s -cost-model -analyze -mcpu=kryo | FileCheck %s
+
+target datalayout = "e-m:e-i64:64-i128:128-n32:64-S128"
+target triple = "aarch64--linux-gnu"
+
+; CHECK-LABEL: vectorInstrCost
+define void @vectorInstrCost() {
+
+    ; Vector extracts - extracting the first element should have a zero cost;
+    ; all other elements should have a cost of two.
+    ;
+    ; CHECK: cost of 0 {{.*}} extractelement <2 x i64> undef, i32 0
+    ; CHECK: cost of 2 {{.*}} extractelement <2 x i64> undef, i32 1
+    %t1 = extractelement <2 x i64> undef, i32 0
+    %t2 = extractelement <2 x i64> undef, i32 1
+
+    ; Vector inserts - inserting the first element should have a zero cost; all
+    ; other elements should have a cost of two.
+    ;
+    ; CHECK: cost of 0 {{.*}} insertelement <2 x i64> undef, i64 undef, i32 0
+    ; CHECK: cost of 2 {{.*}} insertelement <2 x i64> undef, i64 undef, i32 1
+    %t3 = insertelement <2 x i64> undef, i64 undef, i32 0
+    %t4 = insertelement <2 x i64> undef, i64 undef, i32 1
+
+    ret void
+}