[llvm] [RISCV] Fold (X & (3 << 30)) == 0 -> (srliw X, 30) == 0 for RV64. (PR #156769)

[Sergei Barannikov via llvm-commits]

================
@@ -64,3 +64,37 @@ define i1 @test4(i64 %x) {
   %b = icmp eq i64 %a, 0
   ret i1 %b
 }
+
+define i1 @test5(i64 %x) {
+; RV32-LABEL: test5:
+; RV32:       # %bb.0:
+; RV32-NEXT:    srli a0, a0, 29
+; RV32-NEXT:    seqz a0, a0
+; RV32-NEXT:    ret
+;
+; RV64-LABEL: test5:
+; RV64:       # %bb.0:
+; RV64-NEXT:    srliw a0, a0, 29
+; RV64-NEXT:    seqz a0, a0
+; RV64-NEXT:    ret
+  %a = and i64 %x, 3758096384
+  %b = icmp eq i64 %a, 0
+  ret i1 %b
+}
+
+define i1 @test6(i64 %x) {
+; RV32-LABEL: test6:
+; RV32:       # %bb.0:
+; RV32-NEXT:    srli a0, a0, 29
+; RV32-NEXT:    snez a0, a0
+; RV32-NEXT:    ret
+;
+; RV64-LABEL: test6:
+; RV64:       # %bb.0:
+; RV64-NEXT:    srliw a0, a0, 29
+; RV64-NEXT:    snez a0, a0
+; RV64-NEXT:    ret
+  %a = and i64 %x, 3758096384
----------------
s-barannikov wrote:

```suggestion
  %a = and i64 %x, u0xE0000000
```

https://github.com/llvm/llvm-project/pull/156769