[llvm] cabfcf8 - [ARM] Fix conditions for lowering to S[LR]I

Petre-Ionut Tudor via llvm-commits llvm-commits at lists.llvm.org
Fri Apr 17 09:21:24 PDT 2020


Author: Petre-Ionut Tudor
Date: 2020-04-17T17:19:24+01:00
New Revision: cabfcf840a9d15d92466c6774953d3aa399cde92

URL: https://github.com/llvm/llvm-project/commit/cabfcf840a9d15d92466c6774953d3aa399cde92
DIFF: https://github.com/llvm/llvm-project/commit/cabfcf840a9d15d92466c6774953d3aa399cde92.diff

LOG: [ARM] Fix conditions for lowering to S[LR]I

Summary:
Fixed wrong conditions for generating (S[LR]I X, Y, C2) from
(or (and X, BvecC1), (lsl Y, C2)) and added ISel nodes to lower to S[LR]I. The
optimisation is also enabled by default now.

Subscribers: kristof.beyls, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D77387

Added: 
    

Modified: 
    llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
    llvm/lib/Target/AArch64/AArch64ISelLowering.h
    llvm/lib/Target/AArch64/AArch64InstrInfo.td
    llvm/test/CodeGen/AArch64/arm64-sli-sri-opt.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
index f285b4b6ecf6..a52dd21d44b1 100644
--- a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
+++ b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
@@ -99,11 +99,6 @@ STATISTIC(NumTailCalls, "Number of tail calls");
 STATISTIC(NumShiftInserts, "Number of vector shift inserts");
 STATISTIC(NumOptimizedImms, "Number of times immediates were optimized");
 
-static cl::opt<bool>
-EnableAArch64SlrGeneration("aarch64-shift-insert-generation", cl::Hidden,
-                           cl::desc("Allow AArch64 SLI/SRI formation"),
-                           cl::init(false));
-
 // FIXME: The necessary dtprel relocations don't seem to be supported
 // well in the GNU bfd and gold linkers at the moment. Therefore, by
 // default, for now, fall back to GeneralDynamic code generation.
@@ -1323,6 +1318,8 @@ const char *AArch64TargetLowering::getTargetNodeName(unsigned Opcode) const {
   case AArch64ISD::VSHL:              return "AArch64ISD::VSHL";
   case AArch64ISD::VLSHR:             return "AArch64ISD::VLSHR";
   case AArch64ISD::VASHR:             return "AArch64ISD::VASHR";
+  case AArch64ISD::VSLI:              return "AArch64ISD::VSLI";
+  case AArch64ISD::VSRI:              return "AArch64ISD::VSRI";
   case AArch64ISD::CMEQ:              return "AArch64ISD::CMEQ";
   case AArch64ISD::CMGE:              return "AArch64ISD::CMGE";
   case AArch64ISD::CMGT:              return "AArch64ISD::CMGT";
@@ -3145,6 +3142,23 @@ SDValue AArch64TargetLowering::LowerINTRINSIC_WO_CHAIN(SDValue Op,
           "llvm.eh.recoverfp must take a function as the first argument");
     return IncomingFPOp;
   }
+
+  case Intrinsic::aarch64_neon_vsri:
+  case Intrinsic::aarch64_neon_vsli: {
+    EVT Ty = Op.getValueType();
+
+    if (!Ty.isVector())
+      report_fatal_error("Unexpected type for aarch64_neon_vsli");
+
+    uint64_t ShiftAmount = Op.getConstantOperandVal(3);
+    unsigned ElemSizeInBits = Ty.getScalarSizeInBits();
+    assert(ShiftAmount <= ElemSizeInBits);
+
+    bool IsShiftRight = IntNo == Intrinsic::aarch64_neon_vsri;
+    unsigned Opcode = IsShiftRight ? AArch64ISD::VSRI : AArch64ISD::VSLI;
+    return DAG.getNode(Opcode, dl, Ty, Op.getOperand(1), Op.getOperand(2),
+                       Op.getOperand(3));
+  }
   }
 }
 
@@ -7893,8 +7907,9 @@ static unsigned getIntrinsicID(const SDNode *N) {
 
 // Attempt to form a vector S[LR]I from (or (and X, BvecC1), (lsl Y, C2)),
 // to (SLI X, Y, C2), where X and Y have matching vector types, BvecC1 is a
-// BUILD_VECTORs with constant element C1, C2 is a constant, and C1 == ~C2.
-// Also, logical shift right -> sri, with the same structure.
+// BUILD_VECTORs with constant element C1, C2 is a constant, and:
+//   - for the SLI case: C1 == Ones(ElemSizeInBits) >> (ElemSizeInBits - C2)
+//   - for the SRI case: C1 == Ones(ElemSizeInBits) << (ElemSizeInBits - C2)
 static SDValue tryLowerToSLI(SDNode *N, SelectionDAG &DAG) {
   EVT VT = N->getValueType(0);
 
@@ -7927,25 +7942,27 @@ static SDValue tryLowerToSLI(SDNode *N, SelectionDAG &DAG) {
   if (!isAllConstantBuildVector(And.getOperand(1), C1))
     return SDValue();
 
-  // Is C1 == ~C2, taking into account how much one can shift elements of a
-  // particular size?
+  // Is C1 == Ones(ElemSizeInBits) << (ElemSizeInBits - C2) or
+  // C1 == Ones(ElemSizeInBits) >> (ElemSizeInBits - C2), taking into account
+  // how much one can shift elements of a particular size?
   uint64_t C2 = C2node->getZExtValue();
   unsigned ElemSizeInBits = VT.getScalarSizeInBits();
   if (C2 > ElemSizeInBits)
     return SDValue();
   unsigned ElemMask = (1 << ElemSizeInBits) - 1;
-  if ((C1 & ElemMask) != (~C2 & ElemMask))
-    return SDValue();
+  if (IsShiftRight) {
+    if ((C1 & ElemMask) != ((ElemMask << (ElemSizeInBits - C2)) & ElemMask))
+      return SDValue();
+  } else {
+    if ((C1 & ElemMask) != ((ElemMask >> (ElemSizeInBits - C2)) & ElemMask))
+      return SDValue();
+  }
 
   SDValue X = And.getOperand(0);
   SDValue Y = Shift.getOperand(0);
 
-  unsigned Intrin =
-      IsShiftRight ? Intrinsic::aarch64_neon_vsri : Intrinsic::aarch64_neon_vsli;
-  SDValue ResultSLI =
-      DAG.getNode(ISD::INTRINSIC_WO_CHAIN, DL, VT,
-                  DAG.getConstant(Intrin, DL, MVT::i32), X, Y,
-                  Shift.getOperand(1));
+  unsigned Inst = IsShiftRight ? AArch64ISD::VSRI : AArch64ISD::VSLI;
+  SDValue ResultSLI = DAG.getNode(Inst, DL, VT, X, Y, Shift.getOperand(1));
 
   LLVM_DEBUG(dbgs() << "aarch64-lower: transformed: \n");
   LLVM_DEBUG(N->dump(&DAG));
@@ -7959,10 +7976,8 @@ static SDValue tryLowerToSLI(SDNode *N, SelectionDAG &DAG) {
 SDValue AArch64TargetLowering::LowerVectorOR(SDValue Op,
                                              SelectionDAG &DAG) const {
   // Attempt to form a vector S[LR]I from (or (and X, C1), (lsl Y, C2))
-  if (EnableAArch64SlrGeneration) {
-    if (SDValue Res = tryLowerToSLI(Op.getNode(), DAG))
-      return Res;
-  }
+  if (SDValue Res = tryLowerToSLI(Op.getNode(), DAG))
+    return Res;
 
   EVT VT = Op.getValueType();
 

diff  --git a/llvm/lib/Target/AArch64/AArch64ISelLowering.h b/llvm/lib/Target/AArch64/AArch64ISelLowering.h
index a1405335b904..3b3fb40301e4 100644
--- a/llvm/lib/Target/AArch64/AArch64ISelLowering.h
+++ b/llvm/lib/Target/AArch64/AArch64ISelLowering.h
@@ -121,6 +121,10 @@ enum NodeType : unsigned {
   SRSHR_I,
   URSHR_I,
 
+  // Vector shift by constant and insert
+  VSLI,
+  VSRI,
+
   // Vector comparisons
   CMEQ,
   CMGE,
@@ -196,8 +200,10 @@ enum NodeType : unsigned {
   UMULL,
 
   // Reciprocal estimates and steps.
-  FRECPE, FRECPS,
-  FRSQRTE, FRSQRTS,
+  FRECPE,
+  FRECPS,
+  FRSQRTE,
+  FRSQRTS,
 
   SUNPKHI,
   SUNPKLO,

diff  --git a/llvm/lib/Target/AArch64/AArch64InstrInfo.td b/llvm/lib/Target/AArch64/AArch64InstrInfo.td
index f634642a3b59..a0b53eacbc55 100644
--- a/llvm/lib/Target/AArch64/AArch64InstrInfo.td
+++ b/llvm/lib/Target/AArch64/AArch64InstrInfo.td
@@ -231,6 +231,10 @@ def SDT_AArch64ExtVec: SDTypeProfile<1, 3, [SDTCisVec<0>, SDTCisSameAs<0,1>,
                                           SDTCisSameAs<0,2>, SDTCisInt<3>]>;
 def SDT_AArch64vshift : SDTypeProfile<1, 2, [SDTCisSameAs<0,1>, SDTCisInt<2>]>;
 
+def SDT_AArch64vshiftinsert : SDTypeProfile<1, 3, [SDTCisVec<0>, SDTCisInt<3>,
+                                                 SDTCisSameAs<0,1>,
+                                                 SDTCisSameAs<0,2>]>;
+
 def SDT_AArch64unvec : SDTypeProfile<1, 1, [SDTCisVec<0>, SDTCisSameAs<0,1>]>;
 def SDT_AArch64fcmpz : SDTypeProfile<1, 1, []>;
 def SDT_AArch64fcmp  : SDTypeProfile<1, 2, [SDTCisSameAs<1,2>]>;
@@ -469,6 +473,8 @@ def AArch64uqshli : SDNode<"AArch64ISD::UQSHL_I", SDT_AArch64vshift>;
 def AArch64sqshlui : SDNode<"AArch64ISD::SQSHLU_I", SDT_AArch64vshift>;
 def AArch64srshri : SDNode<"AArch64ISD::SRSHR_I", SDT_AArch64vshift>;
 def AArch64urshri : SDNode<"AArch64ISD::URSHR_I", SDT_AArch64vshift>;
+def AArch64vsli : SDNode<"AArch64ISD::VSLI", SDT_AArch64vshiftinsert>;
+def AArch64vsri : SDNode<"AArch64ISD::VSRI", SDT_AArch64vshiftinsert>;
 
 def AArch64not: SDNode<"AArch64ISD::NOT", SDT_AArch64unvec>;
 def AArch64bit: SDNode<"AArch64ISD::BIT", SDT_AArch64trivec>;
@@ -5828,8 +5834,8 @@ defm RSHRN   : SIMDVectorRShiftNarrowBHS<0, 0b10001, "rshrn",
 defm SHL     : SIMDVectorLShiftBHSD<0, 0b01010, "shl", AArch64vshl>;
 defm SHRN    : SIMDVectorRShiftNarrowBHS<0, 0b10000, "shrn",
                           BinOpFrag<(trunc (AArch64vashr node:$LHS, node:$RHS))>>;
-defm SLI     : SIMDVectorLShiftBHSDTied<1, 0b01010, "sli", int_aarch64_neon_vsli>;
-def : Pat<(v1i64 (int_aarch64_neon_vsli (v1i64 FPR64:$Rd), (v1i64 FPR64:$Rn),
+defm SLI     : SIMDVectorLShiftBHSDTied<1, 0b01010, "sli", AArch64vsli>;
+def : Pat<(v1i64 (AArch64vsli (v1i64 FPR64:$Rd), (v1i64 FPR64:$Rn),
                                       (i32 vecshiftL64:$imm))),
           (SLId FPR64:$Rd, FPR64:$Rn, vecshiftL64:$imm)>;
 defm SQRSHRN : SIMDVectorRShiftNarrowBHS<0, 0b10011, "sqrshrn",
@@ -5842,8 +5848,8 @@ defm SQSHRN  : SIMDVectorRShiftNarrowBHS<0, 0b10010, "sqshrn",
                                          int_aarch64_neon_sqshrn>;
 defm SQSHRUN : SIMDVectorRShiftNarrowBHS<1, 0b10000, "sqshrun",
                                          int_aarch64_neon_sqshrun>;
-defm SRI     : SIMDVectorRShiftBHSDTied<1, 0b01000, "sri", int_aarch64_neon_vsri>;
-def : Pat<(v1i64 (int_aarch64_neon_vsri (v1i64 FPR64:$Rd), (v1i64 FPR64:$Rn),
+defm SRI     : SIMDVectorRShiftBHSDTied<1, 0b01000, "sri", AArch64vsri>;
+def : Pat<(v1i64 (AArch64vsri (v1i64 FPR64:$Rd), (v1i64 FPR64:$Rn),
                                       (i32 vecshiftR64:$imm))),
           (SRId FPR64:$Rd, FPR64:$Rn, vecshiftR64:$imm)>;
 defm SRSHR   : SIMDVectorRShiftBHSD<0, 0b00100, "srshr", AArch64srshri>;

diff  --git a/llvm/test/CodeGen/AArch64/arm64-sli-sri-opt.ll b/llvm/test/CodeGen/AArch64/arm64-sli-sri-opt.ll
index b26542d759e4..204e857e45c8 100644
--- a/llvm/test/CodeGen/AArch64/arm64-sli-sri-opt.ll
+++ b/llvm/test/CodeGen/AArch64/arm64-sli-sri-opt.ll
@@ -1,9 +1,9 @@
-; RUN: llc < %s -aarch64-shift-insert-generation=true -mtriple=arm64-eabi -aarch64-neon-syntax=apple | FileCheck %s
+; RUN: llc < %s -mtriple=arm64-eabi -aarch64-neon-syntax=apple | FileCheck %s
 
 define void @testLeftGood(<16 x i8> %src1, <16 x i8> %src2, <16 x i8>* %dest) nounwind {
 ; CHECK-LABEL: testLeftGood:
 ; CHECK: sli.16b v0, v1, #3
-  %and.i = and <16 x i8> %src1, <i8 252, i8 252, i8 252, i8 252, i8 252, i8 252, i8 252, i8 252, i8 252, i8 252, i8 252, i8 252, i8 252, i8 252, i8 252, i8 252>
+  %and.i = and <16 x i8> %src1, <i8 7, i8 7, i8 7, i8 7, i8 7, i8 7, i8 7, i8 7, i8 7, i8 7, i8 7, i8 7, i8 7, i8 7, i8 7, i8 7>
   %vshl_n = shl <16 x i8> %src2, <i8 3, i8 3, i8 3, i8 3, i8 3, i8 3, i8 3, i8 3, i8 3, i8 3, i8 3, i8 3, i8 3, i8 3, i8 3, i8 3>
   %result = or <16 x i8> %and.i, %vshl_n
   store <16 x i8> %result, <16 x i8>* %dest, align 16
@@ -23,7 +23,7 @@ define void @testLeftBad(<16 x i8> %src1, <16 x i8> %src2, <16 x i8>* %dest) nou
 define void @testRightGood(<16 x i8> %src1, <16 x i8> %src2, <16 x i8>* %dest) nounwind {
 ; CHECK-LABEL: testRightGood:
 ; CHECK: sri.16b v0, v1, #3
-  %and.i = and <16 x i8> %src1, <i8 252, i8 252, i8 252, i8 252, i8 252, i8 252, i8 252, i8 252, i8 252, i8 252, i8 252, i8 252, i8 252, i8 252, i8 252, i8 252>
+  %and.i = and <16 x i8> %src1, <i8 224, i8 224, i8 224, i8 224, i8 224, i8 224, i8 224, i8 224, i8 224, i8 224, i8 224, i8 224, i8 224, i8 224, i8 224, i8 224>
   %vshl_n = lshr <16 x i8> %src2, <i8 3, i8 3, i8 3, i8 3, i8 3, i8 3, i8 3, i8 3, i8 3, i8 3, i8 3, i8 3, i8 3, i8 3, i8 3, i8 3>
   %result = or <16 x i8> %and.i, %vshl_n
   store <16 x i8> %result, <16 x i8>* %dest, align 16


        


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