[TTI] Add hook for vector extract with extension

This change adds a new hook for estimating the cost of vector extracts followed
by zero- and sign-extensions. The motivating example for this change is the
SMOV and UMOV instructions on AArch64. These instructions move data from vector
to general purpose registers while performing the corresponding extension
(sign-extend for SMOV and zero-extend for UMOV) at the same time. For these
operations, TargetTransformInfo can assume the extensions are free and only
report the cost of the vector extract. The SLP vectorizer has been updated to
make use of the new hook.

Differential Revision: http://reviews.llvm.org/D18523

llvm-svn: 267725

1 files changed, 14 insertions, 19 deletions

diff --git a/llvm/test/Transforms/SLPVectorizer/AArch64/gather-reduce.ll b/llvm/test/Transforms/SLPVectorizer/AArch64/gather-reduce.ll
index 9c06b24163a..d74e26ec20a 100644
--- a/llvm/test/Transforms/SLPVectorizer/AArch64/gather-reduce.ll
+++ b/llvm/test/Transforms/SLPVectorizer/AArch64/gather-reduce.ll
@@ -1,5 +1,5 @@
-; RUN: opt -S -slp-vectorizer -dce -instcombine < %s | FileCheck %s --check-prefix=PROFITABLE
-; RUN: opt -S -slp-vectorizer -slp-threshold=-12 -dce -instcombine < %s | FileCheck %s --check-prefix=UNPROFITABLE
+; RUN: opt -S -slp-vectorizer -dce -instcombine < %s | FileCheck %s --check-prefix=GENERIC
+; RUN: opt -S -mcpu=kryo -slp-vectorizer -dce -instcombine < %s | FileCheck %s --check-prefix=KRYO
 
 target datalayout = "e-m:e-i64:64-i128:128-n32:64-S128"
 target triple = "aarch64--linux-gnu"
@@ -19,13 +19,13 @@ target triple = "aarch64--linux-gnu"
 ;   return sum;
 ; }
 
-; PROFITABLE-LABEL: @gather_reduce_8x16_i32
+; GENERIC-LABEL: @gather_reduce_8x16_i32
 ;
-; PROFITABLE: [[L:%[a-zA-Z0-9.]+]] = load <8 x i16>
-; PROFITABLE: zext <8 x i16> [[L]] to <8 x i32>
-; PROFITABLE: [[S:%[a-zA-Z0-9.]+]] = sub nsw <8 x i32>
-; PROFITABLE: [[X:%[a-zA-Z0-9.]+]] = extractelement <8 x i32> [[S]]
-; PROFITABLE: sext i32 [[X]] to i64
+; GENERIC: [[L:%[a-zA-Z0-9.]+]] = load <8 x i16>
+; GENERIC: zext <8 x i16> [[L]] to <8 x i32>
+; GENERIC: [[S:%[a-zA-Z0-9.]+]] = sub nsw <8 x i32>
+; GENERIC: [[X:%[a-zA-Z0-9.]+]] = extractelement <8 x i32> [[S]]
+; GENERIC: sext i32 [[X]] to i64
 ;
 define i32 @gather_reduce_8x16_i32(i16* nocapture readonly %a, i16* nocapture readonly %b, i16* nocapture readonly %g, i32 %n) {
 entry:
@@ -138,18 +138,13 @@ for.body:
   br i1 %exitcond, label %for.cond.cleanup.loopexit, label %for.body
 }
 
-; UNPROFITABLE-LABEL: @gather_reduce_8x16_i64
+; KRYO-LABEL: @gather_reduce_8x16_i64
 ;
-; UNPROFITABLE: [[L:%[a-zA-Z0-9.]+]] = load <8 x i16>
-; UNPROFITABLE: zext <8 x i16> [[L]] to <8 x i32>
-; UNPROFITABLE: [[S:%[a-zA-Z0-9.]+]] = sub nsw <8 x i32>
-; UNPROFITABLE: [[X:%[a-zA-Z0-9.]+]] = extractelement <8 x i32> [[S]]
-; UNPROFITABLE: sext i32 [[X]] to i64
-;
-; TODO: Although we can now vectorize this case while converting the i64
-;       subtractions to i32, the cost model currently finds vectorization to be
-;       unprofitable. The cost model is penalizing the sign and zero
-;       extensions in the vectorized version, but they are actually free.
+; KRYO: [[L:%[a-zA-Z0-9.]+]] = load <8 x i16>
+; KRYO: zext <8 x i16> [[L]] to <8 x i32>
+; KRYO: [[S:%[a-zA-Z0-9.]+]] = sub nsw <8 x i32>
+; KRYO: [[X:%[a-zA-Z0-9.]+]] = extractelement <8 x i32> [[S]]
+; KRYO: sext i32 [[X]] to i64
 ;
 define i32 @gather_reduce_8x16_i64(i16* nocapture readonly %a, i16* nocapture readonly %b, i16* nocapture readonly %g, i32 %n) {
 entry: