[X86][AVX] Add support for shuffle decoding of vperm2f128/vperm2i128 with zero'd lanes

The vperm2f128/vperm2i128 shuffle mask decoding was not attempting to deal with shuffles that give zero lanes. This patch fixes this so that the assembly printer can provide shuffle comments.

As this decoder is also used in X86ISelLowering for shuffle combining, I've added an early-out to match existing behaviour. The hope is that we can add zero support in the future, this would allow other ops' decodes (e.g. insertps) to be combined as well.

Differential Revision: http://reviews.llvm.org/D10593

llvm-svn: 241516
This commit is contained in:
Simon Pilgrim 2015-07-06 22:46:46 +00:00
parent 681a56ac58
commit 40343e6b3a
3 changed files with 18 additions and 15 deletions

View File

@ -255,15 +255,13 @@ void DecodeUNPCKLMask(MVT VT, SmallVectorImpl<int> &ShuffleMask) {
void DecodeVPERM2X128Mask(MVT VT, unsigned Imm,
SmallVectorImpl<int> &ShuffleMask) {
if (Imm & 0x88)
return; // Not a shuffle
unsigned HalfSize = VT.getVectorNumElements() / 2;
for (unsigned l = 0; l != 2; ++l) {
unsigned HalfBegin = ((Imm >> (l * 4)) & 0x3) * HalfSize;
unsigned HalfMask = Imm >> (l * 4);
unsigned HalfBegin = (HalfMask & 0x3) * HalfSize;
for (unsigned i = HalfBegin, e = HalfBegin + HalfSize; i != e; ++i)
ShuffleMask.push_back(i);
ShuffleMask.push_back(HalfMask & 8 ? SM_SentinelZero : i);
}
}

View File

@ -4390,6 +4390,7 @@ static SDValue getShuffleVectorZeroOrUndef(SDValue V2, unsigned Idx,
/// IsUnary to true if only uses one source. Note that this will set IsUnary for
/// shuffles which use a single input multiple times, and in those cases it will
/// adjust the mask to only have indices within that single input.
/// FIXME: Add support for Decode*Mask functions that return SM_SentinelZero.
static bool getTargetShuffleMask(SDNode *N, MVT VT,
SmallVectorImpl<int> &Mask, bool &IsUnary) {
unsigned NumElems = VT.getVectorNumElements();
@ -4519,6 +4520,10 @@ static bool getTargetShuffleMask(SDNode *N, MVT VT,
ImmN = N->getOperand(N->getNumOperands()-1);
DecodeVPERM2X128Mask(VT, cast<ConstantSDNode>(ImmN)->getZExtValue(), Mask);
if (Mask.empty()) return false;
// Mask only contains negative index if an element is zero.
if (std::any_of(Mask.begin(), Mask.end(),
[](int M){ return M == SM_SentinelZero; }))
return false;
break;
case X86ISD::MOVSLDUP:
DecodeMOVSLDUPMask(VT, Mask);

View File

@ -269,7 +269,7 @@ entry:
define <4 x double> @vperm2z_0x08(<4 x double> %a) {
; ALL-LABEL: vperm2z_0x08:
; ALL: # BB#0:
; ALL-NEXT: vperm2f128 $40, %ymm0, %ymm0, %ymm0
; ALL-NEXT: vperm2f128 {{.*#+}} ymm0 = zero,zero,ymm0[0,1]
; ALL-NEXT: retq
%s = shufflevector <4 x double> %a, <4 x double> <double 0.0, double 0.0, double undef, double undef>, <4 x i32> <i32 4, i32 5, i32 0, i32 1>
ret <4 x double> %s
@ -279,7 +279,7 @@ define <4 x double> @vperm2z_0x18(<4 x double> %a) {
; ALL-LABEL: vperm2z_0x18:
; ALL: # BB#0:
; ALL-NEXT: vxorpd %ymm1, %ymm1, %ymm1
; ALL-NEXT: vblendpd $12, %ymm0, %ymm1, %ymm0
; ALL-NEXT: vblendpd {{.*#+}} ymm0 = ymm1[0,1],ymm0[2,3]
; ALL-NEXT: retq
%s = shufflevector <4 x double> %a, <4 x double> <double 0.0, double 0.0, double undef, double undef>, <4 x i32> <i32 4, i32 5, i32 2, i32 3>
ret <4 x double> %s
@ -288,7 +288,7 @@ define <4 x double> @vperm2z_0x18(<4 x double> %a) {
define <4 x double> @vperm2z_0x28(<4 x double> %a) {
; ALL-LABEL: vperm2z_0x28:
; ALL: # BB#0:
; ALL-NEXT: vperm2f128 $40, %ymm0, %ymm0, %ymm0
; ALL-NEXT: vperm2f128 {{.*#+}} ymm0 = zero,zero,ymm0[0,1]
; ALL-NEXT: retq
%s = shufflevector <4 x double> <double 0.0, double 0.0, double undef, double undef>, <4 x double> %a, <4 x i32> <i32 0, i32 1, i32 4, i32 5>
ret <4 x double> %s
@ -298,7 +298,7 @@ define <4 x double> @vperm2z_0x38(<4 x double> %a) {
; ALL-LABEL: vperm2z_0x38:
; ALL: # BB#0:
; ALL-NEXT: vxorpd %ymm1, %ymm1, %ymm1
; ALL-NEXT: vblendpd $12, %ymm0, %ymm1, %ymm0
; ALL-NEXT: vblendpd {{.*#+}} ymm0 = ymm1[0,1],ymm0[2,3]
; ALL-NEXT: retq
%s = shufflevector <4 x double> <double 0.0, double 0.0, double undef, double undef>, <4 x double> %a, <4 x i32> <i32 0, i32 1, i32 6, i32 7>
ret <4 x double> %s
@ -307,7 +307,7 @@ define <4 x double> @vperm2z_0x38(<4 x double> %a) {
define <4 x double> @vperm2z_0x80(<4 x double> %a) {
; ALL-LABEL: vperm2z_0x80:
; ALL: # BB#0:
; ALL-NEXT: vperm2f128 $128, %ymm0, %ymm0, %ymm0
; ALL-NEXT: vperm2f128 {{.*#+}} ymm0 = ymm0[0,1],zero,zero
; ALL-NEXT: retq
%s = shufflevector <4 x double> %a, <4 x double> <double 0.0, double 0.0, double undef, double undef>, <4 x i32> <i32 0, i32 1, i32 4, i32 5>
ret <4 x double> %s
@ -316,7 +316,7 @@ define <4 x double> @vperm2z_0x80(<4 x double> %a) {
define <4 x double> @vperm2z_0x81(<4 x double> %a) {
; ALL-LABEL: vperm2z_0x81:
; ALL: # BB#0:
; ALL-NEXT: vperm2f128 $129, %ymm0, %ymm0, %ymm0
; ALL-NEXT: vperm2f128 {{.*#+}} ymm0 = ymm0[2,3],zero,zero
; ALL-NEXT: retq
%s = shufflevector <4 x double> %a, <4 x double> <double 0.0, double 0.0, double undef, double undef>, <4 x i32> <i32 2, i32 3, i32 4, i32 5>
ret <4 x double> %s
@ -325,7 +325,7 @@ define <4 x double> @vperm2z_0x81(<4 x double> %a) {
define <4 x double> @vperm2z_0x82(<4 x double> %a) {
; ALL-LABEL: vperm2z_0x82:
; ALL: # BB#0:
; ALL-NEXT: vperm2f128 $128, %ymm0, %ymm0, %ymm0
; ALL-NEXT: vperm2f128 {{.*#+}} ymm0 = ymm0[0,1],zero,zero
; ALL-NEXT: retq
%s = shufflevector <4 x double> <double 0.0, double 0.0, double undef, double undef>, <4 x double> %a, <4 x i32> <i32 4, i32 5, i32 0, i32 1>
ret <4 x double> %s
@ -334,7 +334,7 @@ define <4 x double> @vperm2z_0x82(<4 x double> %a) {
define <4 x double> @vperm2z_0x83(<4 x double> %a) {
; ALL-LABEL: vperm2z_0x83:
; ALL: # BB#0:
; ALL-NEXT: vperm2f128 $129, %ymm0, %ymm0, %ymm0
; ALL-NEXT: vperm2f128 {{.*#+}} ymm0 = ymm0[2,3],zero,zero
; ALL-NEXT: retq
%s = shufflevector <4 x double> <double 0.0, double 0.0, double undef, double undef>, <4 x double> %a, <4 x i32> <i32 6, i32 7, i32 0, i32 1>
ret <4 x double> %s
@ -345,8 +345,8 @@ define <4 x double> @vperm2z_0x83(<4 x double> %a) {
define <4 x i64> @vperm2z_int_0x83(<4 x i64> %a, <4 x i64> %b) {
; ALL-LABEL: vperm2z_int_0x83:
; ALL: # BB#0:
; AVX1: vperm2f128 $129, %ymm0, %ymm0, %ymm0
; AVX2: vperm2i128 $129, %ymm0, %ymm0, %ymm0
; AVX1: vperm2f128 {{.*#+}} ymm0 = ymm0[2,3],zero,zero
; AVX2: vperm2i128 {{.*#+}} ymm0 = ymm0[2,3],zero,zero
%s = shufflevector <4 x i64> <i64 0, i64 0, i64 undef, i64 undef>, <4 x i64> %a, <4 x i32> <i32 6, i32 7, i32 0, i32 1>
%c = add <4 x i64> %b, %s
ret <4 x i64> %c