[llvm] [AArch64] Add MATCH loops to LoopIdiomVectorizePass (PR #101976)

[Ricardo Jesus via llvm-commits]

================
@@ -0,0 +1,123 @@
+; RUN: opt -mattr=+sve2 -mtriple=aarch64 -passes='loop(loop-idiom-vectorize)' -S < %s | FileCheck -check-prefix=SVE2 %s
+; RUN: opt -mattr=-sve2 -mtriple=aarch64 -passes='loop(loop-idiom-vectorize)' -S < %s | FileCheck -check-prefix=NOSVE2 %s
+
+; Base case based on `libcxx/include/__algorithm/find_first_of.h':
+;   char* find_first_of(char *first, char *last, char *s_first, char *s_last) {
+;     for (; first != last; ++first)
+;       for (char *it = s_first; it != s_last; ++it)
+;         if (*first == *it)
+;           return first;
+;     return last;
+;   }
+define ptr @find_first_of_i8(ptr %0, ptr %1, ptr %2, ptr %3) #0 {
+; SVE2-LABEL: define ptr @find_first_of_i8(
+; SVE2:         {{%.*}} = call <vscale x 16 x i1> @llvm.experimental.vector.match.nxv16i8.v16i8(<vscale x 16 x i8> {{%.*}}, <16 x i8> {{%.*}}, <vscale x 16 x i1> {{%.*}})
----------------
rj-jesus wrote:

Thanks, done. I've also removed the two run lines (replaced by one) to avoid duplicate negative test matching.

https://github.com/llvm/llvm-project/pull/101976