[llvm] [RISCV] Remove SEW operand for load/store and SEW-aware pseudos (PR #90396)

[Michael Maitland via llvm-commits]

================
@@ -769,15 +769,20 @@ class GetVTypeScalarPredicates<VTypeInfo vti> {
 class VPseudoUSLoadNoMask<VReg RetClass,
                           int EEW> :
       Pseudo<(outs RetClass:$rd),
-             (ins RetClass:$dest, GPRMem:$rs1, AVL:$vl, ixlenimm:$sew,
-                  ixlenimm:$policy), []>,
+             !if(!eq(EEW, 1),
+                 (ins RetClass:$dest, GPRMem:$rs1, AVL:$vl, ixlenimm:$sew, ixlenimm:$policy),
+                 (ins RetClass:$dest, GPRMem:$rs1, AVL:$vl, ixlenimm:$policy)), []>,
       RISCVVPseudo,
       RISCVVLE</*Masked*/0, /*Strided*/0, /*FF*/0, !logtwo(EEW), VLMul> {
   let mayLoad = 1;
   let mayStore = 0;
   let hasSideEffects = 0;
   let HasVLOp = 1;
-  let HasSEWOp = 1;
+  defvar hasSEWOp = !eq(EEW, 1);
+  let HasSEWOp = hasSEWOp;
+  // For mask load, EEW = 1.
+  let HasImplictSEW = !not(hasSEWOp);
----------------
michaelmaitland wrote:

nit: I'm not sure if you can do this but would it be simpler to do:

```
let HasSEWOp = !eq(EEW, 1);
// For mask load, EEW = 1.
let HasImplictSEW = !not(HasSEWOp);
let VSEW = !if(HasSEWOp, 0, !logtwo(!div(EEW, 8)));
```

If that is not valid tablegen, please feel free to ignore this comment.

https://github.com/llvm/llvm-project/pull/90396