[llvm] r362323 - [DAG] isBitwiseNot / isConstOrConstSplat - add support for build vector undefs + truncation (PR41020)
Simon Pilgrim via llvm-commits
llvm-commits at lists.llvm.org
Sun Jun 2 04:56:39 PDT 2019
Author: rksimon
Date: Sun Jun 2 04:56:39 2019
New Revision: 362323
URL: http://llvm.org/viewvc/llvm-project?rev=362323&view=rev
Log:
[DAG] isBitwiseNot / isConstOrConstSplat - add support for build vector undefs + truncation (PR41020)
Add (opt-in) support for implicit truncation to isConstOrConstSplat, which allows us to match truncated 'all ones' cases in isBitwiseNot.
PR41020 compares against using ISD::isBuildVectorAllOnes() instead, but that predicate silently accepts any UNDEF elements in the build vector which might not be what we want in isBitwiseNot - so I've added an opt-in 'AllowUndefs' flag that is set to false by default but will allow us to enable it on individual cases where its safe.
Differential Revision: https://reviews.llvm.org/D62783
Modified:
llvm/trunk/include/llvm/CodeGen/SelectionDAGNodes.h
llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
llvm/trunk/test/CodeGen/AArch64/sat-add.ll
Modified: llvm/trunk/include/llvm/CodeGen/SelectionDAGNodes.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/SelectionDAGNodes.h?rev=362323&r1=362322&r2=362323&view=diff
==============================================================================
--- llvm/trunk/include/llvm/CodeGen/SelectionDAGNodes.h (original)
+++ llvm/trunk/include/llvm/CodeGen/SelectionDAGNodes.h Sun Jun 2 04:56:39 2019
@@ -1649,15 +1649,17 @@ SDValue peekThroughExtractSubvectors(SDV
/// Returns true if \p V is a bitwise not operation. Assumes that an all ones
/// constant is canonicalized to be operand 1.
-bool isBitwiseNot(SDValue V);
+bool isBitwiseNot(SDValue V, bool AllowUndefs = false);
/// Returns the SDNode if it is a constant splat BuildVector or constant int.
-ConstantSDNode *isConstOrConstSplat(SDValue N, bool AllowUndefs = false);
+ConstantSDNode *isConstOrConstSplat(SDValue N, bool AllowUndefs = false,
+ bool AllowTruncation = false);
/// Returns the SDNode if it is a demanded constant splat BuildVector or
/// constant int.
ConstantSDNode *isConstOrConstSplat(SDValue N, const APInt &DemandedElts,
- bool AllowUndefs = false);
+ bool AllowUndefs = false,
+ bool AllowTruncation = false);
/// Returns the SDNode if it is a constant splat BuildVector or constant float.
ConstantFPSDNode *isConstOrConstSplatFP(SDValue N, bool AllowUndefs = false);
Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp?rev=362323&r1=362322&r2=362323&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp Sun Jun 2 04:56:39 2019
@@ -8640,14 +8640,18 @@ SDValue llvm::peekThroughExtractSubvecto
return V;
}
-bool llvm::isBitwiseNot(SDValue V) {
+bool llvm::isBitwiseNot(SDValue V, bool AllowUndefs) {
if (V.getOpcode() != ISD::XOR)
return false;
- ConstantSDNode *C = isConstOrConstSplat(peekThroughBitcasts(V.getOperand(1)));
- return C && C->isAllOnesValue();
+ V = peekThroughBitcasts(V.getOperand(1));
+ unsigned NumBits = V.getScalarValueSizeInBits();
+ ConstantSDNode *C =
+ isConstOrConstSplat(V, AllowUndefs, /*AllowTruncation*/ true);
+ return C && (C->getAPIntValue().countTrailingOnes() >= NumBits);
}
-ConstantSDNode *llvm::isConstOrConstSplat(SDValue N, bool AllowUndefs) {
+ConstantSDNode *llvm::isConstOrConstSplat(SDValue N, bool AllowUndefs,
+ bool AllowTruncation) {
if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N))
return CN;
@@ -8655,17 +8659,23 @@ ConstantSDNode *llvm::isConstOrConstSpla
BitVector UndefElements;
ConstantSDNode *CN = BV->getConstantSplatNode(&UndefElements);
- // BuildVectors can truncate their operands. Ignore that case here.
- if (CN && (UndefElements.none() || AllowUndefs) &&
- CN->getValueType(0) == N.getValueType().getScalarType())
- return CN;
+ // BuildVectors can truncate their operands. Ignore that case here unless
+ // AllowTruncation is set.
+ if (CN && (UndefElements.none() || AllowUndefs)) {
+ EVT CVT = CN->getValueType(0);
+ EVT NSVT = N.getValueType().getScalarType();
+ assert(CVT.bitsGE(NSVT) && "Illegal build vector element extension");
+ if (AllowTruncation || (CVT == NSVT))
+ return CN;
+ }
}
return nullptr;
}
ConstantSDNode *llvm::isConstOrConstSplat(SDValue N, const APInt &DemandedElts,
- bool AllowUndefs) {
+ bool AllowUndefs,
+ bool AllowTruncation) {
if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N))
return CN;
@@ -8673,10 +8683,15 @@ ConstantSDNode *llvm::isConstOrConstSpla
BitVector UndefElements;
ConstantSDNode *CN = BV->getConstantSplatNode(DemandedElts, &UndefElements);
- // BuildVectors can truncate their operands. Ignore that case here.
- if (CN && (UndefElements.none() || AllowUndefs) &&
- CN->getValueType(0) == N.getValueType().getScalarType())
- return CN;
+ // BuildVectors can truncate their operands. Ignore that case here unless
+ // AllowTruncation is set.
+ if (CN && (UndefElements.none() || AllowUndefs)) {
+ EVT CVT = CN->getValueType(0);
+ EVT NSVT = N.getValueType().getScalarType();
+ assert(CVT.bitsGE(NSVT) && "Illegal build vector element extension");
+ if (AllowTruncation || (CVT == NSVT))
+ return CN;
+ }
}
return nullptr;
Modified: llvm/trunk/test/CodeGen/AArch64/sat-add.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AArch64/sat-add.ll?rev=362323&r1=362322&r2=362323&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/AArch64/sat-add.ll (original)
+++ llvm/trunk/test/CodeGen/AArch64/sat-add.ll Sun Jun 2 04:56:39 2019
@@ -364,8 +364,7 @@ define <16 x i8> @unsigned_sat_constant_
; CHECK-NEXT: movi v1.16b, #42
; CHECK-NEXT: add v1.16b, v0.16b, v1.16b
; CHECK-NEXT: cmhi v0.16b, v0.16b, v1.16b
-; CHECK-NEXT: bic v1.16b, v1.16b, v0.16b
-; CHECK-NEXT: orr v0.16b, v0.16b, v1.16b
+; CHECK-NEXT: orr v0.16b, v1.16b, v0.16b
; CHECK-NEXT: ret
%a = add <16 x i8> %x, <i8 42, i8 42, i8 42, i8 42, i8 42, i8 42, i8 42, i8 42, i8 42, i8 42, i8 42, i8 42, i8 42, i8 42, i8 42, i8 42>
%c = icmp ugt <16 x i8> %x, %a
@@ -380,8 +379,7 @@ define <16 x i8> @unsigned_sat_constant_
; CHECK-NEXT: movi v2.16b, #213
; CHECK-NEXT: add v1.16b, v0.16b, v1.16b
; CHECK-NEXT: cmhi v0.16b, v0.16b, v2.16b
-; CHECK-NEXT: bic v1.16b, v1.16b, v0.16b
-; CHECK-NEXT: orr v0.16b, v0.16b, v1.16b
+; CHECK-NEXT: orr v0.16b, v1.16b, v0.16b
; CHECK-NEXT: ret
%a = add <16 x i8> %x, <i8 42, i8 42, i8 42, i8 42, i8 42, i8 42, i8 42, i8 42, i8 42, i8 42, i8 42, i8 42, i8 42, i8 42, i8 42, i8 42>
%c = icmp ugt <16 x i8> %x, <i8 -43, i8 -43, i8 -43, i8 -43, i8 -43, i8 -43, i8 -43, i8 -43, i8 -43, i8 -43, i8 -43, i8 -43, i8 -43, i8 -43, i8 -43, i8 -43>
@@ -409,8 +407,7 @@ define <8 x i16> @unsigned_sat_constant_
; CHECK-NEXT: movi v1.8h, #42
; CHECK-NEXT: add v1.8h, v0.8h, v1.8h
; CHECK-NEXT: cmhi v0.8h, v0.8h, v1.8h
-; CHECK-NEXT: bic v1.16b, v1.16b, v0.16b
-; CHECK-NEXT: orr v0.16b, v0.16b, v1.16b
+; CHECK-NEXT: orr v0.16b, v1.16b, v0.16b
; CHECK-NEXT: ret
%a = add <8 x i16> %x, <i16 42, i16 42, i16 42, i16 42, i16 42, i16 42, i16 42, i16 42>
%c = icmp ugt <8 x i16> %x, %a
@@ -425,8 +422,7 @@ define <8 x i16> @unsigned_sat_constant_
; CHECK-NEXT: mvni v2.8h, #42
; CHECK-NEXT: add v1.8h, v0.8h, v1.8h
; CHECK-NEXT: cmhi v0.8h, v0.8h, v2.8h
-; CHECK-NEXT: bic v1.16b, v1.16b, v0.16b
-; CHECK-NEXT: orr v0.16b, v0.16b, v1.16b
+; CHECK-NEXT: orr v0.16b, v1.16b, v0.16b
; CHECK-NEXT: ret
%a = add <8 x i16> %x, <i16 42, i16 42, i16 42, i16 42, i16 42, i16 42, i16 42, i16 42>
%c = icmp ugt <8 x i16> %x, <i16 -43, i16 -43, i16 -43, i16 -43, i16 -43, i16 -43, i16 -43, i16 -43>
@@ -545,8 +541,7 @@ define <16 x i8> @unsigned_sat_variable_
; CHECK: // %bb.0:
; CHECK-NEXT: add v1.16b, v0.16b, v1.16b
; CHECK-NEXT: cmhi v0.16b, v0.16b, v1.16b
-; CHECK-NEXT: bic v1.16b, v1.16b, v0.16b
-; CHECK-NEXT: orr v0.16b, v0.16b, v1.16b
+; CHECK-NEXT: orr v0.16b, v1.16b, v0.16b
; CHECK-NEXT: ret
%a = add <16 x i8> %x, %y
%c = icmp ugt <16 x i8> %x, %a
@@ -560,8 +555,7 @@ define <16 x i8> @unsigned_sat_variable_
; CHECK-NEXT: mvn v2.16b, v1.16b
; CHECK-NEXT: add v1.16b, v0.16b, v1.16b
; CHECK-NEXT: cmhi v0.16b, v0.16b, v2.16b
-; CHECK-NEXT: bic v1.16b, v1.16b, v0.16b
-; CHECK-NEXT: orr v0.16b, v0.16b, v1.16b
+; CHECK-NEXT: orr v0.16b, v1.16b, v0.16b
; CHECK-NEXT: ret
%noty = xor <16 x i8> %y, <i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1, i8 -1>
%a = add <16 x i8> %x, %y
@@ -589,8 +583,7 @@ define <8 x i16> @unsigned_sat_variable_
; CHECK: // %bb.0:
; CHECK-NEXT: add v1.8h, v0.8h, v1.8h
; CHECK-NEXT: cmhi v0.8h, v0.8h, v1.8h
-; CHECK-NEXT: bic v1.16b, v1.16b, v0.16b
-; CHECK-NEXT: orr v0.16b, v0.16b, v1.16b
+; CHECK-NEXT: orr v0.16b, v1.16b, v0.16b
; CHECK-NEXT: ret
%a = add <8 x i16> %x, %y
%c = icmp ugt <8 x i16> %x, %a
@@ -604,8 +597,7 @@ define <8 x i16> @unsigned_sat_variable_
; CHECK-NEXT: mvn v2.16b, v1.16b
; CHECK-NEXT: add v1.8h, v0.8h, v1.8h
; CHECK-NEXT: cmhi v0.8h, v0.8h, v2.8h
-; CHECK-NEXT: bic v1.16b, v1.16b, v0.16b
-; CHECK-NEXT: orr v0.16b, v0.16b, v1.16b
+; CHECK-NEXT: orr v0.16b, v1.16b, v0.16b
; CHECK-NEXT: ret
%noty = xor <8 x i16> %y, <i16 -1, i16 -1, i16 -1, i16 -1, i16 -1, i16 -1, i16 -1, i16 -1>
%a = add <8 x i16> %x, %y
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