[llvm] 39e63bd - [IR][CostModel] A scalable vector shuffle can't be an identity or reverse shuffle.
Craig Topper via llvm-commits
llvm-commits at lists.llvm.org
Mon May 9 21:47:25 PDT 2022
Author: Craig Topper
Date: 2022-05-09T21:37:25-07:00
New Revision: 39e63bd2d848667e44fc05d8a39460f29a3dfbe1
URL: https://github.com/llvm/llvm-project/commit/39e63bd2d848667e44fc05d8a39460f29a3dfbe1
DIFF: https://github.com/llvm/llvm-project/commit/39e63bd2d848667e44fc05d8a39460f29a3dfbe1.diff
LOG: [IR][CostModel] A scalable vector shuffle can't be an identity or reverse shuffle.
Even if the minimum number of elements is 1 and the length doesn't change,
we don't know what vscale is so we can't classify it as identity mask. Instead it
is a zero element splat.
For reverse, we shouldn't classify it as a reverse unless there are at least 2 elements
in the mask. This applies to both fixed and scalable vectors. For fixed vectors, a single
element would be an identity shuffle. For scalable vector it's a zero elt splat.
Reviewed By: sdesmalen, liaolucy
Differential Revision: https://reviews.llvm.org/D124655
Added:
Modified:
llvm/include/llvm/IR/Instructions.h
llvm/lib/IR/Instructions.cpp
llvm/test/Analysis/CostModel/RISCV/rvv-shuffle.ll
llvm/test/Analysis/CostModel/RISCV/shuffle-broadcast.ll
Removed:
################################################################################
diff --git a/llvm/include/llvm/IR/Instructions.h b/llvm/include/llvm/IR/Instructions.h
index c9d48088ab899..fd922c4daa40a 100644
--- a/llvm/include/llvm/IR/Instructions.h
+++ b/llvm/include/llvm/IR/Instructions.h
@@ -2137,6 +2137,12 @@ class ShuffleVectorInst : public Instruction {
static bool isIdentityMask(ArrayRef<int> Mask);
static bool isIdentityMask(const Constant *Mask) {
assert(Mask->getType()->isVectorTy() && "Shuffle needs vector constant.");
+
+ // Not possible to express a shuffle mask for a scalable vector for this
+ // case.
+ if (isa<ScalableVectorType>(Mask->getType()))
+ return false;
+
SmallVector<int, 16> MaskAsInts;
getShuffleMask(Mask, MaskAsInts);
return isIdentityMask(MaskAsInts);
@@ -2147,6 +2153,11 @@ class ShuffleVectorInst : public Instruction {
/// from its input vectors.
/// Example: shufflevector <4 x n> A, <4 x n> B, <4,undef,6,undef>
bool isIdentity() const {
+ // Not possible to express a shuffle mask for a scalable vector for this
+ // case.
+ if (isa<ScalableVectorType>(getType()))
+ return false;
+
return !changesLength() && isIdentityMask(ShuffleMask);
}
diff --git a/llvm/lib/IR/Instructions.cpp b/llvm/lib/IR/Instructions.cpp
index 4eb1e81750440..7615a4dcc4982 100644
--- a/llvm/lib/IR/Instructions.cpp
+++ b/llvm/lib/IR/Instructions.cpp
@@ -2216,7 +2216,13 @@ bool ShuffleVectorInst::isIdentityMask(ArrayRef<int> Mask) {
bool ShuffleVectorInst::isReverseMask(ArrayRef<int> Mask) {
if (!isSingleSourceMask(Mask))
return false;
- for (int i = 0, NumElts = Mask.size(); i < NumElts; ++i) {
+
+ // The number of elements in the mask must be at least 2.
+ int NumElts = Mask.size();
+ if (NumElts < 2)
+ return false;
+
+ for (int i = 0; i < NumElts; ++i) {
if (Mask[i] == -1)
continue;
if (Mask[i] != (NumElts - 1 - i) && Mask[i] != (NumElts + NumElts - 1 - i))
diff --git a/llvm/test/Analysis/CostModel/RISCV/rvv-shuffle.ll b/llvm/test/Analysis/CostModel/RISCV/rvv-shuffle.ll
index 1650ae3e59ec9..b83ebf8623d6b 100644
--- a/llvm/test/Analysis/CostModel/RISCV/rvv-shuffle.ll
+++ b/llvm/test/Analysis/CostModel/RISCV/rvv-shuffle.ll
@@ -11,7 +11,7 @@ define void @vector_broadcast() {
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %3 = shufflevector <vscale x 8 x i16> undef, <vscale x 8 x i16> undef, <vscale x 8 x i32> zeroinitializer
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %4 = shufflevector <vscale x 2 x i32> undef, <vscale x 2 x i32> undef, <vscale x 2 x i32> zeroinitializer
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %5 = shufflevector <vscale x 4 x i32> undef, <vscale x 4 x i32> undef, <vscale x 4 x i32> zeroinitializer
-; CHECK-NEXT: Cost Model: Found an estimated cost of 0 for instruction: %6 = shufflevector <vscale x 1 x i64> undef, <vscale x 1 x i64> undef, <vscale x 1 x i32> zeroinitializer
+; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %6 = shufflevector <vscale x 1 x i64> undef, <vscale x 1 x i64> undef, <vscale x 1 x i32> zeroinitializer
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %7 = shufflevector <vscale x 2 x i64> undef, <vscale x 2 x i64> undef, <vscale x 2 x i32> zeroinitializer
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %8 = shufflevector <vscale x 16 x i1> undef, <vscale x 16 x i1> undef, <vscale x 16 x i32> zeroinitializer
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %9 = shufflevector <vscale x 8 x i1> undef, <vscale x 8 x i1> undef, <vscale x 8 x i32> zeroinitializer
diff --git a/llvm/test/Analysis/CostModel/RISCV/shuffle-broadcast.ll b/llvm/test/Analysis/CostModel/RISCV/shuffle-broadcast.ll
index 6f01149f998a7..0cb57e12e3675 100644
--- a/llvm/test/Analysis/CostModel/RISCV/shuffle-broadcast.ll
+++ b/llvm/test/Analysis/CostModel/RISCV/shuffle-broadcast.ll
@@ -3,44 +3,44 @@
define void @broadcast() #0{
; CHECK-LABEL: 'broadcast'
-; CHECK-NEXT: Cost Model: Found an estimated cost of 0 for instruction: %zero = shufflevector <vscale x 1 x half> undef, <vscale x 1 x half> undef, <vscale x 1 x i32> zeroinitializer
+; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %zero = shufflevector <vscale x 1 x half> undef, <vscale x 1 x half> undef, <vscale x 1 x i32> zeroinitializer
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %1 = shufflevector <vscale x 2 x half> undef, <vscale x 2 x half> undef, <vscale x 2 x i32> zeroinitializer
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %2 = shufflevector <vscale x 4 x half> undef, <vscale x 4 x half> undef, <vscale x 4 x i32> zeroinitializer
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %3 = shufflevector <vscale x 8 x half> undef, <vscale x 8 x half> undef, <vscale x 8 x i32> zeroinitializer
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %4 = shufflevector <vscale x 16 x half> undef, <vscale x 16 x half> undef, <vscale x 16 x i32> zeroinitializer
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %5 = shufflevector <vscale x 32 x half> undef, <vscale x 32 x half> undef, <vscale x 32 x i32> zeroinitializer
-; CHECK-NEXT: Cost Model: Found an estimated cost of 0 for instruction: %6 = shufflevector <vscale x 1 x float> undef, <vscale x 1 x float> undef, <vscale x 1 x i32> zeroinitializer
+; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %6 = shufflevector <vscale x 1 x float> undef, <vscale x 1 x float> undef, <vscale x 1 x i32> zeroinitializer
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %7 = shufflevector <vscale x 2 x float> undef, <vscale x 2 x float> undef, <vscale x 2 x i32> zeroinitializer
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %8 = shufflevector <vscale x 4 x float> undef, <vscale x 4 x float> undef, <vscale x 4 x i32> zeroinitializer
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %9 = shufflevector <vscale x 8 x float> undef, <vscale x 8 x float> undef, <vscale x 8 x i32> zeroinitializer
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %10 = shufflevector <vscale x 16 x float> undef, <vscale x 16 x float> undef, <vscale x 16 x i32> zeroinitializer
-; CHECK-NEXT: Cost Model: Found an estimated cost of 0 for instruction: %11 = shufflevector <vscale x 1 x double> undef, <vscale x 1 x double> undef, <vscale x 1 x i32> zeroinitializer
+; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %11 = shufflevector <vscale x 1 x double> undef, <vscale x 1 x double> undef, <vscale x 1 x i32> zeroinitializer
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %12 = shufflevector <vscale x 2 x double> undef, <vscale x 2 x double> undef, <vscale x 2 x i32> zeroinitializer
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %13 = shufflevector <vscale x 4 x double> undef, <vscale x 4 x double> undef, <vscale x 4 x i32> zeroinitializer
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %14 = shufflevector <vscale x 8 x double> undef, <vscale x 8 x double> undef, <vscale x 8 x i32> zeroinitializer
-; CHECK-NEXT: Cost Model: Found an estimated cost of 0 for instruction: %15 = shufflevector <vscale x 1 x i8> undef, <vscale x 1 x i8> undef, <vscale x 1 x i32> zeroinitializer
+; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %15 = shufflevector <vscale x 1 x i8> undef, <vscale x 1 x i8> undef, <vscale x 1 x i32> zeroinitializer
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %16 = shufflevector <vscale x 2 x i8> undef, <vscale x 2 x i8> undef, <vscale x 2 x i32> zeroinitializer
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %17 = shufflevector <vscale x 4 x i8> undef, <vscale x 4 x i8> undef, <vscale x 4 x i32> zeroinitializer
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %18 = shufflevector <vscale x 8 x i8> undef, <vscale x 8 x i8> undef, <vscale x 8 x i32> zeroinitializer
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %19 = shufflevector <vscale x 16 x i8> undef, <vscale x 16 x i8> undef, <vscale x 16 x i32> zeroinitializer
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %20 = shufflevector <vscale x 32 x i8> undef, <vscale x 32 x i8> undef, <vscale x 32 x i32> zeroinitializer
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %21 = shufflevector <vscale x 64 x i8> undef, <vscale x 64 x i8> undef, <vscale x 64 x i32> zeroinitializer
-; CHECK-NEXT: Cost Model: Found an estimated cost of 0 for instruction: %22 = shufflevector <vscale x 1 x i16> undef, <vscale x 1 x i16> undef, <vscale x 1 x i32> zeroinitializer
+; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %22 = shufflevector <vscale x 1 x i16> undef, <vscale x 1 x i16> undef, <vscale x 1 x i32> zeroinitializer
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %23 = shufflevector <vscale x 2 x i16> undef, <vscale x 2 x i16> undef, <vscale x 2 x i32> zeroinitializer
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %24 = shufflevector <vscale x 4 x i16> undef, <vscale x 4 x i16> undef, <vscale x 4 x i32> zeroinitializer
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %25 = shufflevector <vscale x 8 x i16> undef, <vscale x 8 x i16> undef, <vscale x 8 x i32> zeroinitializer
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %26 = shufflevector <vscale x 16 x i16> undef, <vscale x 16 x i16> undef, <vscale x 16 x i32> zeroinitializer
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %27 = shufflevector <vscale x 32 x i16> undef, <vscale x 32 x i16> undef, <vscale x 32 x i32> zeroinitializer
-; CHECK-NEXT: Cost Model: Found an estimated cost of 0 for instruction: %28 = shufflevector <vscale x 1 x i32> undef, <vscale x 1 x i32> undef, <vscale x 1 x i32> zeroinitializer
+; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %28 = shufflevector <vscale x 1 x i32> undef, <vscale x 1 x i32> undef, <vscale x 1 x i32> zeroinitializer
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %29 = shufflevector <vscale x 2 x i32> undef, <vscale x 2 x i32> undef, <vscale x 2 x i32> zeroinitializer
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %30 = shufflevector <vscale x 4 x i32> undef, <vscale x 4 x i32> undef, <vscale x 4 x i32> zeroinitializer
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %31 = shufflevector <vscale x 8 x i32> undef, <vscale x 8 x i32> undef, <vscale x 8 x i32> zeroinitializer
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %32 = shufflevector <vscale x 16 x i32> undef, <vscale x 16 x i32> undef, <vscale x 16 x i32> zeroinitializer
-; CHECK-NEXT: Cost Model: Found an estimated cost of 0 for instruction: %33 = shufflevector <vscale x 1 x i64> undef, <vscale x 1 x i64> undef, <vscale x 1 x i32> zeroinitializer
+; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %33 = shufflevector <vscale x 1 x i64> undef, <vscale x 1 x i64> undef, <vscale x 1 x i32> zeroinitializer
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %34 = shufflevector <vscale x 2 x i64> undef, <vscale x 2 x i64> undef, <vscale x 2 x i32> zeroinitializer
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %35 = shufflevector <vscale x 4 x i64> undef, <vscale x 4 x i64> undef, <vscale x 4 x i32> zeroinitializer
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %36 = shufflevector <vscale x 8 x i64> undef, <vscale x 8 x i64> undef, <vscale x 8 x i32> zeroinitializer
-; CHECK-NEXT: Cost Model: Found an estimated cost of 0 for instruction: %37 = shufflevector <vscale x 1 x i1> undef, <vscale x 1 x i1> undef, <vscale x 1 x i32> zeroinitializer
+; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %37 = shufflevector <vscale x 1 x i1> undef, <vscale x 1 x i1> undef, <vscale x 1 x i32> zeroinitializer
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %38 = shufflevector <vscale x 2 x i1> undef, <vscale x 2 x i1> undef, <vscale x 2 x i32> zeroinitializer
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %39 = shufflevector <vscale x 4 x i1> undef, <vscale x 4 x i1> undef, <vscale x 4 x i32> zeroinitializer
; CHECK-NEXT: Cost Model: Found an estimated cost of 1 for instruction: %40 = shufflevector <vscale x 8 x i1> undef, <vscale x 8 x i1> undef, <vscale x 8 x i32> zeroinitializer
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