[llvm] [AArch64][GISel] Recover ADDHN from OR comparison masks (PR #213925)

[David Green via llvm-commits]

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@@ -362,6 +362,14 @@ def or_to_bsp: GICombineRule <
   (apply [{ applyOrToBSP(*${root}, MRI, B, ${matchinfo}); }])
 >;
 
+def trunc_or_to_addhn : GICombineRule <
+  (defs root:$root),
+  (match (G_TRUNC $dst, $trunc_src):$root,
+         (G_OR $trunc_src, $src1, $src2),
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davemgreen wrote:

It is usually written the other way around. (I didn't know it worked like this). So that it is in the same other as the IR and the src's are before the later instructions.

https://github.com/llvm/llvm-project/pull/213925