[llvm-branch-commits] [llvm] [Metadata] Preserve MD_prof when merging instructions when one is missing. (PR #132433)

[Snehasish Kumar via llvm-branch-commits]

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@@ -0,0 +1,62 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --check-globals --version 2
+; RUN: opt < %s -passes='simplifycfg<no-sink-common-insts;hoist-common-insts>' -simplifycfg-require-and-preserve-domtree=1 -S | FileCheck %s --check-prefix=HOIST
+
+; Test case based on C++ code with manualy annotated !prof metadata.
+; This is to test that when calls to 'func1' from 'if.then' block
+; and 'if.else' block are hoisted, the branch_weights are merged and
+; attached to merged call rather than dropped.
+;
+; int func1(int a, int b) ;
+; int func2(int a, int b) ;
+
+; int func(int a, int b, bool c) {
+;    int sum= 0;
+;    if(c) {
+;        sum += func1(a, b);
+;    } else {
+;        sum += func1(a, b);
+;        sum -= func2(a, b);
+;    }
+;    return sum;
+; }
+define i32 @_Z4funciib(i32 %a, i32 %b, i1 %c) {
+; HOIST-LABEL: define i32 @_Z4funciib
+; HOIST-SAME: (i32 [[A:%.*]], i32 [[B:%.*]], i1 [[C:%.*]]) {
+; HOIST-NEXT:  entry:
+; HOIST-NEXT:    [[CALL:%.*]] = tail call i32 @_Z5func1ii(i32 [[A]], i32 [[B]]), !prof [[PROF0:![0-9]+]]
+; HOIST-NEXT:    br i1 [[C]], label [[IF_END:%.*]], label [[IF_ELSE:%.*]]
+; HOIST:       if.else:
+; HOIST-NEXT:    [[CALL3:%.*]] = tail call i32 @_Z5func2ii(i32 [[A]], i32 [[B]])
+; HOIST-NEXT:    [[SUB:%.*]] = sub i32 [[CALL]], [[CALL3]]
+; HOIST-NEXT:    br label [[IF_END]]
+; HOIST:       if.end:
+; HOIST-NEXT:    [[SUM_0:%.*]] = phi i32 [ [[SUB]], [[IF_ELSE]] ], [ [[CALL]], [[ENTRY:%.*]] ]
+; HOIST-NEXT:    ret i32 [[SUM_0]]
+;
+entry:
+  br i1 %c, label %if.then, label %if.else
+
+if.then:                                          ; preds = %entry
+  %call = tail call i32 @_Z5func1ii(i32 %a, i32 %b), !prof !0
+  br label %if.end
+
+if.else:                                          ; preds = %entry
+  %call1 = tail call i32 @_Z5func1ii(i32 %a, i32 %b)
+  %call3 = tail call i32 @_Z5func2ii(i32 %a, i32 %b)
+  %sub = sub i32 %call1, %call3
+  br label %if.end
+
+if.end:                                           ; preds = %if.else, %if.then
+  %sum.0 = phi i32 [ %call, %if.then ], [ %sub, %if.else ]
+  ret i32 %sum.0
+}
+
+declare i32 @_Z5func1ii(i32, i32)
+
+declare i32 @_Z5func2ii(i32, i32)
+
+!0 = !{!"branch_weights", i32 10}
+!1 = !{!"branch_weights", i32 90}
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snehasish wrote:

Removed.

https://github.com/llvm/llvm-project/pull/132433