[clang] [llvm] [AArch64][SVE] Lower unpredicated loads/stores as LDR/STR. (PR #127837)

[Paul Walker via llvm-commits]

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@@ -2993,6 +2993,22 @@ let Predicates = [HasSVE_or_SME] in {
   defm : unpred_loadstore_bitcast<nxv2i64>;
   defm : unpred_loadstore_bitcast<nxv2f64>;
 
+  // Allow using LDR/STR to avoid the predicate dependence.
+  let Predicates = [IsLE, AllowMisalignedMemAccesses] in
+    foreach Ty = [ nxv16i8, nxv8i16, nxv4i32, nxv2i64, nxv8f16, nxv4f32, nxv2f64, nxv8bf16 ] in {
+      let AddedComplexity = 2 in {
+        def : Pat<(Ty (load (am_sve_indexed_s9 GPR64sp:$base, simm9:$offset))),
+                  (LDR_ZXI GPR64sp:$base, simm9:$offset)>;
+        def : Pat<(store Ty:$val, (am_sve_indexed_s9 GPR64sp:$base, simm9:$offset)),
+                  (STR_ZXI ZPR:$val, GPR64sp:$base, simm9:$offset)>;
+      }
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paulwalker-arm wrote:

Can this live inside `unpred_loadstore_bitcast` because it will be nicer to have all the "unconventional" results of normal loads and stores together. This will mean we have a couple of duplicate patterns for the `nxv16i8` type but I think that should be ok?

https://github.com/llvm/llvm-project/pull/127837