[llvm] r218175 - [x86] Generalize the single-element insertion lowering to work with
Chandler Carruth
chandlerc at gmail.com
Fri Sep 19 20:32:25 PDT 2014
Author: chandlerc
Date: Fri Sep 19 22:32:25 2014
New Revision: 218175
URL: http://llvm.org/viewvc/llvm-project?rev=218175&view=rev
Log:
[x86] Generalize the single-element insertion lowering to work with
floating point types and use it for both v2f64 and v2i64 single-element
insertion lowering.
This fixes the last non-AVX performance regression test case I've gotten
of for the new vector shuffle lowering. There is obvious analogous
lowering for v4f32 that I'll add in a follow-up patch (because with
INSERTPS, v4f32 requires special treatment). After that, its AVX stuff.
Modified:
llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
llvm/trunk/test/CodeGen/X86/vector-shuffle-128-v2.ll
Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.cpp?rev=218175&r1=218174&r2=218175&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Fri Sep 19 22:32:25 2014
@@ -7553,7 +7553,7 @@ static SDValue lowerVectorShuffleAsZeroO
///
/// This is a common pattern that we have especially efficient patterns to lower
/// across all subtarget feature sets.
-static SDValue lowerIntegerElementInsertionVectorShuffle(
+static SDValue lowerVectorShuffleAsElementInsertion(
MVT VT, SDLoc DL, SDValue V1, SDValue V2, ArrayRef<int> Mask,
const X86Subtarget *Subtarget, SelectionDAG &DAG) {
SmallBitVector Zeroable = computeZeroableShuffleElements(Mask, V1, V2);
@@ -7561,10 +7561,30 @@ static SDValue lowerIntegerElementInsert
int V2Index = std::find_if(Mask.begin(), Mask.end(),
[&Mask](int M) { return M >= (int)Mask.size(); }) -
Mask.begin();
+ if (Mask.size() == 2) {
+ if (!Zeroable[V2Index ^ 1]) {
+ // For 2-wide masks we may be able to just invert the inputs. We use an xor
+ // with 2 to flip from {2,3} to {0,1} and vice versa.
+ int InverseMask[2] = {Mask[0] < 0 ? -1 : (Mask[0] ^ 2),
+ Mask[1] < 0 ? -1 : (Mask[1] ^ 2)};
+ if (Zeroable[V2Index])
+ return lowerVectorShuffleAsElementInsertion(VT, DL, V2, V1, InverseMask,
+ Subtarget, DAG);
+ else
+ return SDValue();
+ }
+ } else {
+ for (int i = 0, Size = Mask.size(); i < Size; ++i)
+ if (i != V2Index && !Zeroable[i])
+ return SDValue(); // Not inserting into a zero vector.
+ }
- for (int i = 0, Size = Mask.size(); i < Size; ++i)
- if (i != V2Index && !Zeroable[i])
- return SDValue(); // Not inserting into a zero vector.
+ // Step over any bitcasts on either input so we can scan the actual
+ // BUILD_VECTOR nodes.
+ while (V1.getOpcode() == ISD::BITCAST)
+ V1 = V1.getOperand(0);
+ while (V2.getOpcode() == ISD::BITCAST)
+ V2 = V2.getOperand(0);
// Check for a single input from a SCALAR_TO_VECTOR node.
// FIXME: All of this should be canonicalized into INSERT_VECTOR_ELT and
@@ -7579,10 +7599,9 @@ static SDValue lowerIntegerElementInsert
SDValue V2S = V2.getOperand(Mask[V2Index] - Mask.size());
// First, we need to zext the scalar if it is smaller than an i32.
- MVT EltVT = VT.getVectorElementType();
- assert(EltVT == V2S.getSimpleValueType() &&
- "Different scalar and element types!");
MVT ExtVT = VT;
+ MVT EltVT = VT.getVectorElementType();
+ V2S = DAG.getNode(ISD::BITCAST, DL, EltVT, V2S);
if (EltVT == MVT::i8 || EltVT == MVT::i16) {
// Zero-extend directly to i32.
ExtVT = MVT::v4i32;
@@ -7650,6 +7669,12 @@ static SDValue lowerV2F64VectorShuffle(S
if (isShuffleEquivalent(Mask, 1, 3))
return DAG.getNode(X86ISD::UNPCKH, DL, MVT::v2f64, V1, V2);
+ // If we have a single input, insert that into V1 if we can do so cheaply.
+ if ((Mask[0] >= 2) + (Mask[1] >= 2) == 1)
+ if (SDValue Insertion = lowerVectorShuffleAsElementInsertion(
+ MVT::v2f64, DL, V1, V2, Mask, Subtarget, DAG))
+ return Insertion;
+
if (Subtarget->hasSSE41())
if (SDValue Blend =
lowerVectorShuffleAsBlend(DL, MVT::v2f64, V1, V2, Mask, DAG))
@@ -7697,6 +7722,13 @@ static SDValue lowerV2I64VectorShuffle(S
if (isShuffleEquivalent(Mask, 1, 3))
return DAG.getNode(X86ISD::UNPCKH, DL, MVT::v2i64, V1, V2);
+ // If we have a single input from V2 insert that into V1 if we can do so
+ // cheaply.
+ if ((Mask[0] >= 2) + (Mask[1] >= 2) == 1)
+ if (SDValue Insertion = lowerVectorShuffleAsElementInsertion(
+ MVT::v2i64, DL, V1, V2, Mask, Subtarget, DAG))
+ return Insertion;
+
if (Subtarget->hasSSE41())
if (SDValue Blend =
lowerVectorShuffleAsBlend(DL, MVT::v2i64, V1, V2, Mask, DAG))
@@ -7923,8 +7955,8 @@ static SDValue lowerV4I32VectorShuffle(S
// There are special ways we can lower some single-element blends.
if (NumV2Elements == 1)
- if (SDValue V = lowerIntegerElementInsertionVectorShuffle(
- MVT::v4i32, DL, V1, V2, Mask, Subtarget, DAG))
+ if (SDValue V = lowerVectorShuffleAsElementInsertion(MVT::v4i32, DL, V1, V2,
+ Mask, Subtarget, DAG))
return V;
if (Subtarget->hasSSE41())
@@ -8604,8 +8636,8 @@ static SDValue lowerV8I16VectorShuffle(S
// There are special ways we can lower some single-element blends.
if (NumV2Inputs == 1)
- if (SDValue V = lowerIntegerElementInsertionVectorShuffle(
- MVT::v8i16, DL, V1, V2, Mask, Subtarget, DAG))
+ if (SDValue V = lowerVectorShuffleAsElementInsertion(MVT::v8i16, DL, V1, V2,
+ Mask, Subtarget, DAG))
return V;
if (Subtarget->hasSSE41())
@@ -8920,8 +8952,8 @@ static SDValue lowerV16I8VectorShuffle(S
// There are special ways we can lower some single-element blends.
if (NumV2Elements == 1)
- if (SDValue V = lowerIntegerElementInsertionVectorShuffle(
- MVT::v16i8, DL, V1, V2, Mask, Subtarget, DAG))
+ if (SDValue V = lowerVectorShuffleAsElementInsertion(MVT::v16i8, DL, V1, V2,
+ Mask, Subtarget, DAG))
return V;
// Check whether a compaction lowering can be done. This handles shuffles
Modified: llvm/trunk/test/CodeGen/X86/vector-shuffle-128-v2.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/vector-shuffle-128-v2.ll?rev=218175&r1=218174&r2=218175&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/vector-shuffle-128-v2.ll (original)
+++ llvm/trunk/test/CodeGen/X86/vector-shuffle-128-v2.ll Fri Sep 19 22:32:25 2014
@@ -400,6 +400,44 @@ define <2 x i64> @shuffle_v2i64_31_copy(
}
+define <2 x i64> @insert_reg_and_zero_v2i64(i64 %a) {
+; ALL-LABEL: @insert_reg_and_zero_v2i64
+; ALL: movd %rdi, %xmm0
+; ALL-NEXT: retq
+ %v = insertelement <2 x i64> undef, i64 %a, i32 0
+ %shuffle = shufflevector <2 x i64> %v, <2 x i64> zeroinitializer, <2 x i32> <i32 0, i32 3>
+ ret <2 x i64> %shuffle
+}
+
+define <2 x i64> @insert_mem_and_zero_v2i64(i64* %ptr) {
+; ALL-LABEL: @insert_mem_and_zero_v2i64
+; ALL: movq (%rdi), %xmm0
+; ALL-NEXT: retq
+ %a = load i64* %ptr
+ %v = insertelement <2 x i64> undef, i64 %a, i32 0
+ %shuffle = shufflevector <2 x i64> %v, <2 x i64> zeroinitializer, <2 x i32> <i32 0, i32 3>
+ ret <2 x i64> %shuffle
+}
+
+define <2 x double> @insert_reg_and_zero_v2f64(double %a) {
+; ALL-LABEL: @insert_reg_and_zero_v2f64
+; ALL: movq %xmm0, %xmm0
+; ALL-NEXT: retq
+ %v = insertelement <2 x double> undef, double %a, i32 0
+ %shuffle = shufflevector <2 x double> %v, <2 x double> zeroinitializer, <2 x i32> <i32 0, i32 3>
+ ret <2 x double> %shuffle
+}
+
+define <2 x double> @insert_mem_and_zero_v2f64(double* %ptr) {
+; ALL-LABEL: @insert_mem_and_zero_v2f64
+; ALL: movsd (%rdi), %xmm0
+; ALL-NEXT: retq
+ %a = load double* %ptr
+ %v = insertelement <2 x double> undef, double %a, i32 0
+ %shuffle = shufflevector <2 x double> %v, <2 x double> zeroinitializer, <2 x i32> <i32 0, i32 3>
+ ret <2 x double> %shuffle
+}
+
define <2 x double> @insert_dup_reg_v2f64(double %a) {
; SSE2-LABEL: @insert_dup_reg_v2f64
; SSE2: movlhps {{.*}} # xmm0 = xmm0[0,0]
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