[llvm] [LICM] Fix dropped metadata (PR #95221)

[Nikita Popov via llvm-commits]

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@@ -0,0 +1,40 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -S -passes=licm < %s | FileCheck %s
+
+define void @test(ptr %in, ptr %out) {
+; CHECK-LABEL: @test(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[I_NEXT:%.*]], [[LOOP]] ]
+; CHECK-NEXT:    [[I_NEXT]] = add i32 [[I]], 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ult i32 [[I_NEXT]], 10
+; CHECK-NEXT:    br i1 [[CMP]], label [[LOOP]], label [[EXIT:%.*]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[I_LCSSA:%.*]] = phi i32 [ [[I]], [[LOOP]] ]
+; CHECK-NEXT:    [[GEP_LE:%.*]] = getelementptr <4 x i16>, ptr [[IN:%.*]], i32 [[I_LCSSA]]
+; CHECK-NEXT:    [[LOAD_LE:%.*]] = call <4 x i16> @llvm.masked.load.v4i16.p0(ptr [[GEP_LE]], i32 2, <4 x i1> <i1 true, i1 false, i1 true, i1 false>, <4 x i16> <i16 0, i16 poison, i16 0, i16 poison>), !alias.scope [[META0:![0-9]+]], !noalias [[META0]]
+; CHECK-NEXT:    [[REDUCE_LE:%.*]] = call i16 @llvm.vector.reduce.add.v4i16(<4 x i16> [[LOAD_LE]])
+; CHECK-NEXT:    store i16 [[REDUCE_LE]], ptr [[OUT:%.*]], align 2
+; CHECK-NEXT:    ret void
+;
+entry:
+  br label %loop
+
+loop:                              ; preds = %loop, %entry
+  %i = phi i32 [ 0, %entry ], [ %i.next, %loop ]
+  %gep = getelementptr <4 x i16>, ptr %in, i32 %i
+  %load = call <4 x i16> @llvm.masked.load.v4i16.p0(ptr %gep, i32 2, <4 x i1> <i1 true, i1 false, i1 true, i1 false>, <4 x i16> <i16 0, i16 poison, i16 0, i16 poison>), !alias.scope !2, !noalias !2
+  %reduce = call i16 @llvm.vector.reduce.add.v4i16(<4 x i16> %load)
+  %i.next = add i32 %i, 1
+  %cmp = icmp ult i32 %i.next, 10
+  br i1 %cmp, label %loop, label %exit
+
+exit:                               ; preds = %loop
+  store i16 %reduce, ptr %out
----------------
nikic wrote:

Can simplify this a bit more by replacing this store+param with a return.

https://github.com/llvm/llvm-project/pull/95221