[llvm] [TableGen][RISCV][AArch64][GISel] Properly implement isAnyExtLoad/isSignExtLoad/isZeroExtLoad for IsAtomic in SelectionDAG. (PR #137096)

[Matt Arsenault via llvm-commits]

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@@ -1903,15 +1916,54 @@ def atomic_load_sext_16 :
   let MemoryVT = i16;
 }
 
+def atomic_load_sext_32 :
+  PatFrag<(ops node:$ptr), (atomic_load_sext node:$ptr)> {
+  let IsAtomic = true; // FIXME: Should be IsLoad and/or IsAtomic?
+  let MemoryVT = i32;
+}
+
+def atomic_load_aext_8 :
+  PatFrag<(ops node:$ptr), (atomic_load_aext node:$ptr)> {
+  let IsAtomic = true; // FIXME: Should be IsLoad and/or IsAtomic?
+  let MemoryVT = i8;
+}
+
+def atomic_load_aext_16 :
+  PatFrag<(ops node:$ptr), (atomic_load_aext node:$ptr)> {
+  let IsAtomic = true; // FIXME: Should be IsLoad and/or IsAtomic?
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arsenm wrote:

There's some wonky logic in both emitters that seem to assume you only set one of these bits per pat frag. I don't think it works to set both, should probably do something about that.

https://github.com/llvm/llvm-project/pull/137096