Teach the DAGCombiner how to fold concat_vector nodes when the input is two

BUILD_VECTOR nodes, e.g.:

(concat_vectors (BUILD_VECTOR a1, a2, a3, a4), (BUILD_VECTOR b1, b2, b3, b4))
->
(BUILD_VECTOR a1, a2, a3, a4, b1, b2, b3, b4)

This fixes an issue with AVX, where a sequence was not recognized as a 256-bit
vbroadcast due to the concat_vectors.

llvm-svn: 201158
This commit is contained in:
Robert Lougher 2014-02-11 15:42:46 +00:00
parent 2228cd3f07
commit 7d9084ffa1
3 changed files with 141 additions and 0 deletions

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@ -10136,6 +10136,26 @@ SDValue DAGCombiner::visitCONCAT_VECTORS(SDNode *N) {
}
}
// fold (concat_vectors (BUILD_VECTOR A, B, ...), (BUILD_VECTOR C, D, ...))
// -> (BUILD_VECTOR A, B, ..., C, D, ...)
if (N->getNumOperands() == 2 &&
N->getOperand(0).getOpcode() == ISD::BUILD_VECTOR &&
N->getOperand(1).getOpcode() == ISD::BUILD_VECTOR) {
EVT VT = N->getValueType(0);
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
SmallVector<SDValue, 8> Opnds;
unsigned BuildVecNumElts = N0.getNumOperands();
for (unsigned i = 0; i != BuildVecNumElts; ++i)
Opnds.push_back(N0.getOperand(i));
for (unsigned i = 0; i != BuildVecNumElts; ++i)
Opnds.push_back(N1.getOperand(i));
return DAG.getNode(ISD::BUILD_VECTOR, SDLoc(N), VT, &Opnds[0],
Opnds.size());
}
// Type legalization of vectors and DAG canonicalization of SHUFFLE_VECTOR
// nodes often generate nop CONCAT_VECTOR nodes.
// Scan the CONCAT_VECTOR operands and look for a CONCAT operations that

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@ -141,3 +141,66 @@ entry:
ret <4 x float> %t
}
; These tests check that a vbroadcast instruction is used when we have a splat
; formed from a concat_vectors (via the shufflevector) of two BUILD_VECTORs
; (via the insertelements).
; CHECK-LABEL: splat_concat1
; CHECK-NOT: vinsertf128
; CHECK: vbroadcastss (%
; CHECK-NEXT: ret
define <8 x float> @splat_concat1(float* %p) {
%1 = load float* %p, align 4
%2 = insertelement <4 x float> undef, float %1, i32 0
%3 = insertelement <4 x float> %2, float %1, i32 1
%4 = insertelement <4 x float> %3, float %1, i32 2
%5 = insertelement <4 x float> %4, float %1, i32 3
%6 = shufflevector <4 x float> %5, <4 x float> undef, <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 0, i32 1, i32 2, i32 3>
ret <8 x float> %6
}
; CHECK-LABEL: splat_concat2
; CHECK-NOT: vinsertf128
; CHECK: vbroadcastss (%
; CHECK-NEXT: ret
define <8 x float> @splat_concat2(float* %p) {
%1 = load float* %p, align 4
%2 = insertelement <4 x float> undef, float %1, i32 0
%3 = insertelement <4 x float> %2, float %1, i32 1
%4 = insertelement <4 x float> %3, float %1, i32 2
%5 = insertelement <4 x float> %4, float %1, i32 3
%6 = insertelement <4 x float> undef, float %1, i32 0
%7 = insertelement <4 x float> %6, float %1, i32 1
%8 = insertelement <4 x float> %7, float %1, i32 2
%9 = insertelement <4 x float> %8, float %1, i32 3
%10 = shufflevector <4 x float> %5, <4 x float> %9, <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
ret <8 x float> %10
}
; CHECK-LABEL: splat_concat3
; CHECK-NOT: vinsertf128
; CHECK: vbroadcastsd (%
; CHECK-NEXT: ret
define <4 x double> @splat_concat3(double* %p) {
%1 = load double* %p, align 8
%2 = insertelement <2 x double> undef, double %1, i32 0
%3 = insertelement <2 x double> %2, double %1, i32 1
%4 = shufflevector <2 x double> %3, <2 x double> undef, <4 x i32> <i32 0, i32 1, i32 0, i32 1>
ret <4 x double> %4
}
; CHECK-LABEL: splat_concat4
; CHECK-NOT: vinsertf128
; CHECK: vbroadcastsd (%
; CHECK-NEXT: ret
define <4 x double> @splat_concat4(double* %p) {
%1 = load double* %p, align 8
%2 = insertelement <2 x double> undef, double %1, i32 0
%3 = insertelement <2 x double> %2, double %1, i32 1
%4 = insertelement <2 x double> undef, double %1, i32 0
%5 = insertelement <2 x double> %2, double %1, i32 1
%6 = shufflevector <2 x double> %3, <2 x double> %5, <4 x i32> <i32 0, i32 1, i32 2, i32 3>
ret <4 x double> %6
}

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@ -355,3 +355,61 @@ define <16 x i8> @_inreg16xi8(<16 x i8> %a) {
%b = shufflevector <16 x i8> %a, <16 x i8> undef, <16 x i32> zeroinitializer
ret <16 x i8> %b
}
; These tests check that a vbroadcast instruction is used when we have a splat
; formed from a concat_vectors (via the shufflevector) of two BUILD_VECTORs
; (via the insertelements).
; CHECK-LABEL: splat_concat1
; CHECK-NOT: vinsertf128
; CHECK: vbroadcastss
; CHECK-NEXT: ret
define <8 x float> @splat_concat1(float %f) {
%1 = insertelement <4 x float> undef, float %f, i32 0
%2 = insertelement <4 x float> %1, float %f, i32 1
%3 = insertelement <4 x float> %2, float %f, i32 2
%4 = insertelement <4 x float> %3, float %f, i32 3
%5 = shufflevector <4 x float> %4, <4 x float> undef, <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 0, i32 1, i32 2, i32 3>
ret <8 x float> %5
}
; CHECK-LABEL: splat_concat2
; CHECK-NOT: vinsertf128
; CHECK: vbroadcastss
; CHECK-NEXT: ret
define <8 x float> @splat_concat2(float %f) {
%1 = insertelement <4 x float> undef, float %f, i32 0
%2 = insertelement <4 x float> %1, float %f, i32 1
%3 = insertelement <4 x float> %2, float %f, i32 2
%4 = insertelement <4 x float> %3, float %f, i32 3
%5 = insertelement <4 x float> undef, float %f, i32 0
%6 = insertelement <4 x float> %5, float %f, i32 1
%7 = insertelement <4 x float> %6, float %f, i32 2
%8 = insertelement <4 x float> %7, float %f, i32 3
%9 = shufflevector <4 x float> %4, <4 x float> %8, <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
ret <8 x float> %9
}
; CHECK-LABEL: splat_concat3
; CHECK-NOT: vinsertf128
; CHECK: vbroadcastsd
; CHECK-NEXT: ret
define <4 x double> @splat_concat3(double %d) {
%1 = insertelement <2 x double> undef, double %d, i32 0
%2 = insertelement <2 x double> %1, double %d, i32 1
%3 = shufflevector <2 x double> %2, <2 x double> undef, <4 x i32> <i32 0, i32 1, i32 0, i32 1>
ret <4 x double> %3
}
; CHECK-LABEL: splat_concat4
; CHECK-NOT: vinsertf128
; CHECK: vbroadcastsd
; CHECK-NEXT: ret
define <4 x double> @splat_concat4(double %d) {
%1 = insertelement <2 x double> undef, double %d, i32 0
%2 = insertelement <2 x double> %1, double %d, i32 1
%3 = insertelement <2 x double> undef, double %d, i32 0
%4 = insertelement <2 x double> %3, double %d, i32 1
%5 = shufflevector <2 x double> %2, <2 x double> %4, <4 x i32> <i32 0, i32 1, i32 2, i32 3>
ret <4 x double> %5
}