[llvm] [SelectionDAG][Targets] Replace atomic_load_8/atomic_load_16 with atomic_load_*ext_8/atomic_load_*ext_16 where possible. (PR #137279)

[Craig Topper via llvm-commits]

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@@ -1536,14 +1536,13 @@ multiclass ScratchFLATLoadPats_D16_t16<string inst, SDPatternOperator node, Valu
 
 let OtherPredicates = [HasFlatAddressSpace] in {
 
-def : FlatLoadPat <FLAT_LOAD_UBYTE, atomic_load_8_flat, i32>;
-def : FlatLoadPat <FLAT_LOAD_UBYTE, atomic_load_8_flat, i16>;
+def : FlatLoadPat <FLAT_LOAD_UBYTE, atomic_load_aext_8_flat, i32>;
+def : FlatLoadPat <FLAT_LOAD_UBYTE, atomic_load_aext_8_flat, i16>;
 def : FlatLoadPat <FLAT_LOAD_UBYTE, atomic_load_zext_8_flat, i32>;
 def : FlatLoadPat <FLAT_LOAD_UBYTE, atomic_load_zext_8_flat, i16>;
-def : FlatLoadPat <FLAT_LOAD_USHORT, atomic_load_16_flat, i32>;
+def : FlatLoadPat <FLAT_LOAD_USHORT, atomic_load_aext_16_flat, i32>;
 def : FlatLoadPat <FLAT_LOAD_USHORT, atomic_load_16_flat, i16>;
 def : FlatLoadPat <FLAT_LOAD_USHORT, atomic_load_zext_16_flat, i32>;
-def : FlatLoadPat <FLAT_LOAD_USHORT, atomic_load_zext_16_flat, i16>;
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topperc wrote:

This pattern looked to be impossible to match. It's a zextload with i16 memory and result type.

https://github.com/llvm/llvm-project/pull/137279