From 15fd6bae0e4938ebbd4751a4ba1c85b4145894b5 Mon Sep 17 00:00:00 2001
From: Fraser Cormack <fraser@codeplay.com>
Date: Wed, 13 Jan 2021 13:33:38 +0000
Subject: [PATCH] [RISCV] Extend RVV VType info with the type's AVL (NFC)

This patch factors out the "VLMax" operand passed to most
scalable-vector ISel patterns into a property of each VType.

This is seen as a preparatory change to allow RVV in the future to
more easily support fixed-length vector types with constrained vector
lengths, with the AVL operand set to the length of the fixed-length
vector. It has no effect on the scalable code generation path.

Reviewed By: HsiangKai

Differential Revision: https://reviews.llvm.org/D94594
---
 .../Target/RISCV/RISCVInstrInfoVPseudos.td    |  7 ++
 .../Target/RISCV/RISCVInstrInfoVSDPatterns.td | 95 ++++++++++---------
 2 files changed, 57 insertions(+), 45 deletions(-)

diff --git a/llvm/lib/Target/RISCV/RISCVInstrInfoVPseudos.td b/llvm/lib/Target/RISCV/RISCVInstrInfoVPseudos.td
index 1406c8645f73..85826b26eedf 100644
--- a/llvm/lib/Target/RISCV/RISCVInstrInfoVPseudos.td
+++ b/llvm/lib/Target/RISCV/RISCVInstrInfoVPseudos.td
@@ -137,6 +137,9 @@ class VTypeInfo<ValueType Vec, ValueType Mas, int Sew, VReg Reg, LMULInfo M,
   LMULInfo LMul = M;
   ValueType Scalar = Scal;
   RegisterClass ScalarRegClass = ScalarReg;
+  // The pattern fragment which produces the AVL operand, representing the
+  // "natural" vector length for this type. For scalable vectors this is VLMax.
+  OutPatFrag AVL = VLMax;
 }
 
 class GroupVTypeInfo<ValueType Vec, ValueType VecM1, ValueType Mas, int Sew,
@@ -234,6 +237,10 @@ class MTypeInfo<ValueType Mas, LMULInfo M, string Bx> {
   int SEW = 8;
   LMULInfo LMul = M;
   string BX = Bx; // Appendix of mask operations.
+  // The pattern fragment which produces the AVL operand, representing the
+  // "natural" vector length for this mask type. For scalable masks this is
+  // VLMax.
+  OutPatFrag AVL = VLMax;
 }
 
 defset list<MTypeInfo> AllMasks = {
diff --git a/llvm/lib/Target/RISCV/RISCVInstrInfoVSDPatterns.td b/llvm/lib/Target/RISCV/RISCVInstrInfoVSDPatterns.td
index 5b4051c534a3..4a6571010ec1 100644
--- a/llvm/lib/Target/RISCV/RISCVInstrInfoVSDPatterns.td
+++ b/llvm/lib/Target/RISCV/RISCVInstrInfoVSDPatterns.td
@@ -47,6 +47,7 @@ multiclass VPatUSLoadStoreSDNode<LLVMType type,
                                  LLVMType mask_type,
                                  int sew,
                                  LMULInfo vlmul,
+                                 OutPatFrag avl,
                                  RegisterClass reg_rs1,
                                  VReg reg_class>
 {
@@ -54,16 +55,16 @@ multiclass VPatUSLoadStoreSDNode<LLVMType type,
   defvar store_instr = !cast<Instruction>("PseudoVSE"#sew#"_V_"#vlmul.MX);
   // Load
   def : Pat<(type (load reg_rs1:$rs1)),
-            (load_instr reg_rs1:$rs1, VLMax, sew)>;
+            (load_instr reg_rs1:$rs1, avl, sew)>;
   // Store
   def : Pat<(store type:$rs2, reg_rs1:$rs1),
-            (store_instr reg_class:$rs2, reg_rs1:$rs1, VLMax, sew)>;
+            (store_instr reg_class:$rs2, reg_rs1:$rs1, avl, sew)>;
 }
 
 multiclass VPatUSLoadStoreSDNodes<RegisterClass reg_rs1> {
   foreach vti = AllVectors in
     defm "" : VPatUSLoadStoreSDNode<vti.Vector, vti.Mask, vti.SEW, vti.LMul,
-                                    reg_rs1, vti.RegClass>;
+                                    vti.AVL, reg_rs1, vti.RegClass>;
 }
 
 class VPatBinarySDNode_VV<SDNode vop,
@@ -73,6 +74,7 @@ class VPatBinarySDNode_VV<SDNode vop,
                           ValueType mask_type,
                           int sew,
                           LMULInfo vlmul,
+                          OutPatFrag avl,
                           VReg RetClass,
                           VReg op_reg_class> :
     Pat<(result_type (vop
@@ -81,7 +83,7 @@ class VPatBinarySDNode_VV<SDNode vop,
         (!cast<Instruction>(instruction_name#"_VV_"# vlmul.MX)
                      op_reg_class:$rs1,
                      op_reg_class:$rs2,
-                     VLMax, sew)>;
+                     avl, sew)>;
 
 class VPatBinarySDNode_XI<SDNode vop,
                           string instruction_name,
@@ -92,6 +94,7 @@ class VPatBinarySDNode_XI<SDNode vop,
                           ValueType mask_type,
                           int sew,
                           LMULInfo vlmul,
+                          OutPatFrag avl,
                           VReg RetClass,
                           VReg vop_reg_class,
                           ComplexPattern SplatPatKind,
@@ -102,17 +105,17 @@ class VPatBinarySDNode_XI<SDNode vop,
         (!cast<Instruction>(instruction_name#_#suffix#_# vlmul.MX)
                      vop_reg_class:$rs1,
                      xop_kind:$rs2,
-                     VLMax, sew)>;
+                     avl, sew)>;
 
 multiclass VPatBinarySDNode_VV_VX<SDNode vop, string instruction_name>
 {
   foreach vti = AllIntegerVectors in {
     def : VPatBinarySDNode_VV<vop, instruction_name,
                               vti.Vector, vti.Vector, vti.Mask, vti.SEW,
-                              vti.LMul, vti.RegClass, vti.RegClass>;
+                              vti.LMul, vti.AVL, vti.RegClass, vti.RegClass>;
     def : VPatBinarySDNode_XI<vop, instruction_name, "VX",
                               vti.Vector, vti.Vector, XLenVT, vti.Mask, vti.SEW,
-                              vti.LMul, vti.RegClass, vti.RegClass,
+                              vti.LMul, vti.AVL, vti.RegClass, vti.RegClass,
                               SplatPat, GPR>;
   }
 }
@@ -123,14 +126,14 @@ multiclass VPatBinarySDNode_VV_VX_VI<SDNode vop, string instruction_name,
   foreach vti = AllIntegerVectors in {
     def : VPatBinarySDNode_VV<vop, instruction_name,
                               vti.Vector, vti.Vector, vti.Mask, vti.SEW,
-                              vti.LMul, vti.RegClass, vti.RegClass>;
+                              vti.LMul, vti.AVL, vti.RegClass, vti.RegClass>;
     def : VPatBinarySDNode_XI<vop, instruction_name, "VX",
                               vti.Vector, vti.Vector, XLenVT, vti.Mask, vti.SEW,
-                              vti.LMul, vti.RegClass, vti.RegClass,
+                              vti.LMul, vti.AVL, vti.RegClass, vti.RegClass,
                               SplatPat, GPR>;
     def : VPatBinarySDNode_XI<vop, instruction_name, "VI",
                               vti.Vector, vti.Vector, XLenVT, vti.Mask, vti.SEW,
-                              vti.LMul, vti.RegClass, vti.RegClass,
+                              vti.LMul, vti.AVL, vti.RegClass, vti.RegClass,
                               !cast<ComplexPattern>(SplatPat#_#ImmType),
                               ImmType>;
   }
@@ -144,6 +147,7 @@ class VPatBinarySDNode_VF<SDNode vop,
                           ValueType mask_type,
                           int sew,
                           LMULInfo vlmul,
+                          OutPatFrag avl,
                           VReg RetClass,
                           VReg vop_reg_class,
                           DAGOperand xop_kind> :
@@ -152,16 +156,16 @@ class VPatBinarySDNode_VF<SDNode vop,
         (!cast<Instruction>(instruction_name#"_VF_"#vlmul.MX)
                      vop_reg_class:$rs1,
                      ToFPR32<xop_type, xop_kind, "rs2">.ret,
-                     VLMax, sew)>;
+                     avl, sew)>;
 
 multiclass VPatBinaryFPSDNode_VV_VF<SDNode vop, string instruction_name> {
   foreach vti = AllFloatVectors in {
     def : VPatBinarySDNode_VV<vop, instruction_name,
                               vti.Vector, vti.Vector, vti.Mask, vti.SEW,
-                              vti.LMul, vti.RegClass, vti.RegClass>;
+                              vti.LMul, vti.AVL, vti.RegClass, vti.RegClass>;
     def : VPatBinarySDNode_VF<vop, instruction_name,
                               vti.Vector, vti.Vector, vti.Scalar, vti.Mask,
-                              vti.SEW, vti.LMul, vti.RegClass, vti.RegClass,
+                              vti.SEW, vti.LMul, vti.AVL, vti.RegClass, vti.RegClass,
                               vti.ScalarRegClass>;
   }
 }
@@ -173,7 +177,7 @@ multiclass VPatBinaryFPSDNode_R_VF<SDNode vop, string instruction_name> {
               (!cast<Instruction>(instruction_name#"_VF_"#fvti.LMul.MX)
                            fvti.RegClass:$rs1,
                            ToFPR32<fvti.Scalar, fvti.ScalarRegClass, "rs2">.ret,
-                           VLMax, fvti.SEW)>;
+                           fvti.AVL, fvti.SEW)>;
 }
 
 multiclass VPatIntegerSetCCSDNode_VV<CondCode cc,
@@ -186,7 +190,7 @@ multiclass VPatIntegerSetCCSDNode_VV<CondCode cc,
               SwapHelper<(instruction),
                          (instruction vti.RegClass:$rs1),
                          (instruction vti.RegClass:$rs2),
-                         (instruction VLMax, vti.SEW),
+                         (instruction vti.AVL, vti.SEW),
                          swap>.Value>;
   }
 }
@@ -204,7 +208,7 @@ multiclass VPatIntegerSetCCSDNode_XI<CondCode cc,
               SwapHelper<(instruction),
                          (instruction vti.RegClass:$rs1),
                          (instruction xop_kind:$rs2),
-                         (instruction VLMax, vti.SEW),
+                         (instruction vti.AVL, vti.SEW),
                          swap>.Value>;
   }
 }
@@ -242,7 +246,7 @@ multiclass VPatFPSetCCSDNode_VV<CondCode cc, string instruction_name> {
                                 (fvti.Vector fvti.RegClass:$rs2),
                                 cc)),
               (!cast<Instruction>(instruction_name#"_VV_"#fvti.LMul.MX)
-                  fvti.RegClass:$rs1, fvti.RegClass:$rs2, VLMax, fvti.SEW)>;
+                  fvti.RegClass:$rs1, fvti.RegClass:$rs2, fvti.AVL, fvti.SEW)>;
 }
 
 multiclass VPatFPSetCCSDNode_VF<CondCode cc, string instruction_name> {
@@ -253,7 +257,7 @@ multiclass VPatFPSetCCSDNode_VF<CondCode cc, string instruction_name> {
               (!cast<Instruction>(instruction_name#"_VF_"#fvti.LMul.MX)
                   fvti.RegClass:$rs1,
                   ToFPR32<fvti.Scalar, fvti.ScalarRegClass, "rs2">.ret,
-                  VLMax, fvti.SEW)>;
+                  fvti.AVL, fvti.SEW)>;
 }
 
 multiclass VPatFPSetCCSDNode_FV<CondCode cc, string swapped_op_instruction_name> {
@@ -264,7 +268,7 @@ multiclass VPatFPSetCCSDNode_FV<CondCode cc, string swapped_op_instruction_name>
               (!cast<Instruction>(swapped_op_instruction_name#"_VF_"#fvti.LMul.MX)
                   fvti.RegClass:$rs1,
                   ToFPR32<fvti.Scalar, fvti.ScalarRegClass, "rs2">.ret,
-                  VLMax, fvti.SEW)>;
+                  fvti.AVL, fvti.SEW)>;
 }
 
 multiclass VPatFPSetCCSDNode_VV_VF_FV<CondCode cc,
@@ -283,7 +287,7 @@ multiclass VPatExtendSDNode_V<list<SDNode> ops, string inst_name, string suffix,
     foreach op = ops in
       def : Pat<(vti.Vector (op (fti.Vector fti.RegClass:$rs2))),
                 (!cast<Instruction>(inst_name#"_"#suffix#"_"#vti.LMul.MX)
-                    fti.RegClass:$rs2, VLMax, vti.SEW)>;
+                    fti.RegClass:$rs2, fti.AVL, vti.SEW)>;
   }
 }
 
@@ -306,11 +310,11 @@ foreach vti = AllIntegerVectors in {
   def : Pat<(sub (vti.Vector (SplatPat XLenVT:$rs2)),
                  (vti.Vector vti.RegClass:$rs1)),
             (!cast<Instruction>("PseudoVRSUB_VX_"# vti.LMul.MX)
-                 vti.RegClass:$rs1, GPR:$rs2, VLMax, vti.SEW)>;
+                 vti.RegClass:$rs1, GPR:$rs2, vti.AVL, vti.SEW)>;
   def : Pat<(sub (vti.Vector (SplatPat_simm5 XLenVT:$rs2)),
                  (vti.Vector vti.RegClass:$rs1)),
             (!cast<Instruction>("PseudoVRSUB_VI_"# vti.LMul.MX)
-                 vti.RegClass:$rs1, simm5:$rs2, VLMax, vti.SEW)>;
+                 vti.RegClass:$rs1, simm5:$rs2, vti.AVL, vti.SEW)>;
 }
 
 // 12.3. Vector Integer Extension
@@ -343,7 +347,7 @@ foreach vtiTofti = AllFractionableVF2IntVectors in {
   defvar fti = vtiTofti.Fti;
   def : Pat<(fti.Vector (riscv_trunc_vector (vti.Vector vti.RegClass:$rs1))),
             (!cast<Instruction>("PseudoVNSRL_WI_"#fti.LMul.MX)
-                vti.RegClass:$rs1, 0, VLMax, fti.SEW)>;
+                vti.RegClass:$rs1, 0, fti.AVL, fti.SEW)>;
 }
 
 // 12.8. Vector Integer Comparison Instructions
@@ -390,47 +394,48 @@ foreach vti = AllIntegerVectors in {
   def : Pat<(vti.Vector (vselect (vti.Mask VMV0:$vm), vti.RegClass:$rs1,
                                                       vti.RegClass:$rs2)),
             (!cast<Instruction>("PseudoVMERGE_VVM_"#vti.LMul.MX)
-                 vti.RegClass:$rs2, vti.RegClass:$rs1, VMV0:$vm, VLMax, vti.SEW)>;
+                 vti.RegClass:$rs2, vti.RegClass:$rs1, VMV0:$vm,
+                 vti.AVL, vti.SEW)>;
 
   def : Pat<(vti.Vector (vselect (vti.Mask VMV0:$vm), (SplatPat XLenVT:$rs1),
                                                       vti.RegClass:$rs2)),
             (!cast<Instruction>("PseudoVMERGE_VXM_"#vti.LMul.MX)
-                 vti.RegClass:$rs2, GPR:$rs1, VMV0:$vm, VLMax, vti.SEW)>;
+                 vti.RegClass:$rs2, GPR:$rs1, VMV0:$vm, vti.AVL, vti.SEW)>;
 
   def : Pat<(vti.Vector (vselect (vti.Mask VMV0:$vm), (SplatPat_simm5 simm5:$rs1),
                                                       vti.RegClass:$rs2)),
             (!cast<Instruction>("PseudoVMERGE_VIM_"#vti.LMul.MX)
-                 vti.RegClass:$rs2, simm5:$rs1, VMV0:$vm, VLMax, vti.SEW)>;
+                 vti.RegClass:$rs2, simm5:$rs1, VMV0:$vm, vti.AVL, vti.SEW)>;
 }
 
 // 16.1. Vector Mask-Register Logical Instructions
 foreach mti = AllMasks in {
   def : Pat<(mti.Mask (and VR:$rs1, VR:$rs2)),
             (!cast<Instruction>("PseudoVMAND_MM_"#mti.LMul.MX)
-                 VR:$rs1, VR:$rs2, VLMax, mti.SEW)>;
+                 VR:$rs1, VR:$rs2, mti.AVL, mti.SEW)>;
   def : Pat<(mti.Mask (or VR:$rs1, VR:$rs2)),
             (!cast<Instruction>("PseudoVMOR_MM_"#mti.LMul.MX)
-                 VR:$rs1, VR:$rs2, VLMax, mti.SEW)>;
+                 VR:$rs1, VR:$rs2, mti.AVL, mti.SEW)>;
   def : Pat<(mti.Mask (xor VR:$rs1, VR:$rs2)),
             (!cast<Instruction>("PseudoVMXOR_MM_"#mti.LMul.MX)
-                 VR:$rs1, VR:$rs2, VLMax, mti.SEW)>;
+                 VR:$rs1, VR:$rs2, mti.AVL, mti.SEW)>;
 
   def : Pat<(mti.Mask (vnot (and VR:$rs1, VR:$rs2))),
             (!cast<Instruction>("PseudoVMNAND_MM_"#mti.LMul.MX)
-                 VR:$rs1, VR:$rs2, VLMax, mti.SEW)>;
+                 VR:$rs1, VR:$rs2, mti.AVL, mti.SEW)>;
   def : Pat<(mti.Mask (vnot (or VR:$rs1, VR:$rs2))),
             (!cast<Instruction>("PseudoVMNOR_MM_"#mti.LMul.MX)
-                 VR:$rs1, VR:$rs2, VLMax, mti.SEW)>;
+                 VR:$rs1, VR:$rs2, mti.AVL, mti.SEW)>;
   def : Pat<(mti.Mask (vnot (xor VR:$rs1, VR:$rs2))),
             (!cast<Instruction>("PseudoVMXNOR_MM_"#mti.LMul.MX)
-                 VR:$rs1, VR:$rs2, VLMax, mti.SEW)>;
+                 VR:$rs1, VR:$rs2, mti.AVL, mti.SEW)>;
 
   def : Pat<(mti.Mask (and VR:$rs1, (vnot VR:$rs2))),
             (!cast<Instruction>("PseudoVMANDNOT_MM_"#mti.LMul.MX)
-                 VR:$rs1, VR:$rs2, VLMax, mti.SEW)>;
+                 VR:$rs1, VR:$rs2, mti.AVL, mti.SEW)>;
   def : Pat<(mti.Mask (or VR:$rs1, (vnot VR:$rs2))),
             (!cast<Instruction>("PseudoVMORNOT_MM_"#mti.LMul.MX)
-                 VR:$rs1, VR:$rs2, VLMax, mti.SEW)>;
+                 VR:$rs1, VR:$rs2, mti.AVL, mti.SEW)>;
 }
 
 } // Predicates = [HasStdExtV]
@@ -468,7 +473,7 @@ foreach fvti = AllFloatVectors in {
                                                         fvti.RegClass:$rs2)),
             (!cast<Instruction>("PseudoVMERGE_VVM_"#fvti.LMul.MX)
                  fvti.RegClass:$rs2, fvti.RegClass:$rs1, VMV0:$vm,
-                 VLMax, fvti.SEW)>;
+                 fvti.AVL, fvti.SEW)>;
 
   def : Pat<(fvti.Vector (vselect (fvti.Mask VMV0:$vm),
                                   (splat_vector fvti.ScalarRegClass:$rs1),
@@ -476,13 +481,13 @@ foreach fvti = AllFloatVectors in {
             (!cast<Instruction>("PseudoVFMERGE_VFM_"#fvti.LMul.MX)
                  fvti.RegClass:$rs2,
                  ToFPR32<fvti.Scalar, fvti.ScalarRegClass, "rs1">.ret,
-                 VMV0:$vm, VLMax, fvti.SEW)>;
+                 VMV0:$vm, fvti.AVL, fvti.SEW)>;
 
   def : Pat<(fvti.Vector (vselect (fvti.Mask VMV0:$vm),
                                   (splat_vector (fvti.Scalar fpimm0)),
                                   fvti.RegClass:$rs2)),
             (!cast<Instruction>("PseudoVMERGE_VIM_"#fvti.LMul.MX)
-                 fvti.RegClass:$rs2, 0, VMV0:$vm, VLMax, fvti.SEW)>;
+                 fvti.RegClass:$rs2, 0, VMV0:$vm, fvti.AVL, fvti.SEW)>;
 }
 } // Predicates = [HasStdExtV, HasStdExtF]
 
@@ -494,17 +499,17 @@ let Predicates = [HasStdExtV] in {
 foreach vti = AllIntegerVectors in {
   def : Pat<(vti.Vector (splat_vector GPR:$rs1)),
             (!cast<Instruction>("PseudoVMV_V_X_" # vti.LMul.MX)
-              GPR:$rs1, VLMax, vti.SEW)>;
+              GPR:$rs1, vti.AVL, vti.SEW)>;
   def : Pat<(vti.Vector (splat_vector simm5:$rs1)),
             (!cast<Instruction>("PseudoVMV_V_I_" # vti.LMul.MX)
-              simm5:$rs1, VLMax, vti.SEW)>;
+              simm5:$rs1, vti.AVL, vti.SEW)>;
 }
 
 foreach mti = AllMasks in {
   def : Pat<(mti.Mask immAllOnesV),
-            (!cast<Instruction>("PseudoVMSET_M_"#mti.BX) VLMax, mti.SEW)>;
+            (!cast<Instruction>("PseudoVMSET_M_"#mti.BX) mti.AVL, mti.SEW)>;
   def : Pat<(mti.Mask immAllZerosV),
-            (!cast<Instruction>("PseudoVMCLR_M_"#mti.BX) VLMax, mti.SEW)>;
+            (!cast<Instruction>("PseudoVMCLR_M_"#mti.BX) mti.AVL, mti.SEW)>;
 }
 } // Predicates = [HasStdExtV]
 
@@ -513,10 +518,10 @@ foreach vti = AllIntegerVectors in {
   if !eq(vti.SEW, 64) then {
     def : Pat<(vti.Vector (rv32_splat_i64 GPR:$rs1)),
               (!cast<Instruction>("PseudoVMV_V_X_" # vti.LMul.MX)
-                GPR:$rs1, VLMax, vti.SEW)>;
+                GPR:$rs1, vti.AVL, vti.SEW)>;
     def : Pat<(vti.Vector (rv32_splat_i64 simm5:$rs1)),
               (!cast<Instruction>("PseudoVMV_V_I_" # vti.LMul.MX)
-                simm5:$rs1, VLMax, vti.SEW)>;
+                simm5:$rs1, vti.AVL, vti.SEW)>;
   }
 }
 } // Predicates = [HasStdExtV, IsRV32]
@@ -526,10 +531,10 @@ foreach fvti = AllFloatVectors in {
   def : Pat<(fvti.Vector (splat_vector fvti.ScalarRegClass:$rs1)),
             (!cast<Instruction>("PseudoVFMV_V_F_"#fvti.LMul.MX)
               ToFPR32<fvti.Scalar, fvti.ScalarRegClass, "rs1">.ret,
-              VLMax, fvti.SEW)>;
+              fvti.AVL, fvti.SEW)>;
 
   def : Pat<(fvti.Vector (splat_vector (fvti.Scalar fpimm0))),
             (!cast<Instruction>("PseudoVMV_V_I_"#fvti.LMul.MX)
-              0, VLMax, fvti.SEW)>;
+              0, fvti.AVL, fvti.SEW)>;
 }
 } // Predicates = [HasStdExtV, HasStdExtF]