[RISCV] Remove unneeded indexed segment load/store vector pseudo instruction.

We had more combinations of data and index lmuls than we needed.

Also add some asserts to verify that the IndexVT and data VT have
the same element count when we isel these pseudo instructions.

Author: topperc

llvm/lib/Target/RISCV/RISCVISelDAGToDAG.cpp

@@ -297,6 +297,9 @@ void RISCVDAGToDAGISel::selectVLXSEG(SDNode *Node, bool IsMasked,
   Operands.push_back(SEW);
   Operands.push_back(Node->getOperand(0)); // Chain.
 
+  assert(VT.getVectorElementCount() == IndexVT.getVectorElementCount() &&
+         "Element count mismatch");
+
   RISCVVLMUL IndexLMUL = getLMUL(IndexVT);
   unsigned IndexScalarSize = IndexVT.getScalarSizeInBits();
   const RISCV::VLXSEGPseudo *P = RISCV::getVLXSEGPseudo(
@@ -376,6 +379,9 @@ void RISCVDAGToDAGISel::selectVSXSEG(SDNode *Node, bool IsMasked,
   Operands.push_back(SEW);
   Operands.push_back(Node->getOperand(0)); // Chain.
 
+  assert(VT.getVectorElementCount() == IndexVT.getVectorElementCount() &&
+         "Element count mismatch");
+
   RISCVVLMUL IndexLMUL = getLMUL(IndexVT);
   unsigned IndexScalarSize = IndexVT.getScalarSizeInBits();
   const RISCV::VSXSEGPseudo *P = RISCV::getVSXSEGPseudo(

llvm/lib/Target/RISCV/RISCVInstrInfoVPseudos.td

@@ -2004,19 +2004,28 @@ multiclass VPseudoSSegLoad {
 }
 
 multiclass VPseudoISegLoad<bit Ordered> {
-  foreach idx_eew = EEWList in {  // EEW for index argument.
-    foreach idx_lmul = MxSet<idx_eew>.m in {  // LMUL for index argument.
-      foreach val_lmul = MxList.m in {  // LMUL for the value.
-        defvar IdxLInfo = idx_lmul.MX;
-        defvar IdxVreg = idx_lmul.vrclass;
-        defvar ValLInfo = val_lmul.MX;
-        let VLMul = val_lmul.value in {
-          foreach nf = NFSet<val_lmul>.L in {
-            defvar ValVreg = SegRegClass<val_lmul, nf>.RC;
-            def nf # "EI" # idx_eew # "_V_" # IdxLInfo # "_" # ValLInfo :
-              VPseudoISegLoadNoMask<ValVreg, IdxVreg, idx_eew, idx_lmul.value, nf, Ordered>;
-            def nf # "EI" # idx_eew # "_V_" # IdxLInfo # "_" # ValLInfo # "_MASK" :
-              VPseudoISegLoadMask<ValVreg, IdxVreg, idx_eew, idx_lmul.value, nf, Ordered>;
+  foreach idx_eew = EEWList in {
+    foreach sew = EEWList in {
+      foreach val_lmul = MxSet<sew>.m in {
+        defvar octuple_lmul = octuple_from_str<val_lmul.MX>.ret;
+        // Calculate emul = eew * lmul / sew
+        defvar octuple_emul = !srl(!mul(idx_eew, octuple_lmul), shift_amount<sew>.val);
+        if !and(!ge(octuple_emul, 1), !le(octuple_emul, 64)) then {
+          defvar ValLInfo = val_lmul.MX;
+          defvar IdxLInfo = octuple_to_str<octuple_emul>.ret;
+          defvar idx_lmul = !cast<LMULInfo>("V_" # IdxLInfo);
+          defvar Vreg = val_lmul.vrclass;
+          defvar IdxVreg = idx_lmul.vrclass;
+          let VLMul = val_lmul.value in {
+            foreach nf = NFSet<val_lmul>.L in {
+              defvar ValVreg = SegRegClass<val_lmul, nf>.RC;
+              def nf # "EI" # idx_eew # "_V_" # IdxLInfo # "_" # ValLInfo :
+                VPseudoISegLoadNoMask<ValVreg, IdxVreg, idx_eew, idx_lmul.value,
+                                      nf, Ordered>;
+              def nf # "EI" # idx_eew # "_V_" # IdxLInfo # "_" # ValLInfo # "_MASK" :
+                VPseudoISegLoadMask<ValVreg, IdxVreg, idx_eew, idx_lmul.value,
+                                    nf, Ordered>;
+            }
           }
         }
       }
@@ -2055,19 +2064,28 @@ multiclass VPseudoSSegStore {
 }
 
 multiclass VPseudoISegStore<bit Ordered> {
-  foreach idx_eew = EEWList in {  // EEW for index argument.
-    foreach idx_lmul = MxSet<idx_eew>.m in {  // LMUL for index argument.
-      foreach val_lmul = MxList.m in {  // LMUL for the value.
-        defvar IdxLInfo = idx_lmul.MX;
-        defvar IdxVreg = idx_lmul.vrclass;
-        defvar ValLInfo = val_lmul.MX;
-        let VLMul = val_lmul.value in {
-          foreach nf = NFSet<val_lmul>.L in {
-            defvar ValVreg = SegRegClass<val_lmul, nf>.RC;
-            def nf # "EI" # idx_eew # "_V_" # IdxLInfo # "_" # ValLInfo :
-              VPseudoISegStoreNoMask<ValVreg, IdxVreg, idx_eew, idx_lmul.value, nf, Ordered>;
-            def nf # "EI" # idx_eew # "_V_" # IdxLInfo # "_" # ValLInfo # "_MASK" :
-              VPseudoISegStoreMask<ValVreg, IdxVreg, idx_eew, idx_lmul.value, nf, Ordered>;
+  foreach idx_eew = EEWList in {
+    foreach sew = EEWList in {
+      foreach val_lmul = MxSet<sew>.m in {
+        defvar octuple_lmul = octuple_from_str<val_lmul.MX>.ret;
+        // Calculate emul = eew * lmul / sew
+        defvar octuple_emul = !srl(!mul(idx_eew, octuple_lmul), shift_amount<sew>.val);
+        if !and(!ge(octuple_emul, 1), !le(octuple_emul, 64)) then {
+          defvar ValLInfo = val_lmul.MX;
+          defvar IdxLInfo = octuple_to_str<octuple_emul>.ret;
+          defvar idx_lmul = !cast<LMULInfo>("V_" # IdxLInfo);
+          defvar Vreg = val_lmul.vrclass;
+          defvar IdxVreg = idx_lmul.vrclass;
+          let VLMul = val_lmul.value in {
+            foreach nf = NFSet<val_lmul>.L in {
+              defvar ValVreg = SegRegClass<val_lmul, nf>.RC;
+              def nf # "EI" # idx_eew # "_V_" # IdxLInfo # "_" # ValLInfo :
+                VPseudoISegStoreNoMask<ValVreg, IdxVreg, idx_eew, idx_lmul.value,
+                                       nf, Ordered>;
+              def nf # "EI" # idx_eew # "_V_" # IdxLInfo # "_" # ValLInfo # "_MASK" :
+                VPseudoISegStoreMask<ValVreg, IdxVreg, idx_eew, idx_lmul.value,
+                                     nf, Ordered>;
+            }
           }
         }
       }