[AMDGPU][StructurizeCFG] pre-commit tests: maintain branch_weights metadata (#109812)

Author: jmmartinez

llvm/test/Transforms/StructurizeCFG/structurizer-keep-perf-md.ll

@@ -0,0 +1,72 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
+; RUN: opt -S -mtriple=amdgcn-- -passes=structurizecfg %s | FileCheck -check-prefix=OPT %s
+
+define amdgpu_ps i32 @if_else(i32 %0) {
+; OPT-LABEL: define amdgpu_ps i32 @if_else(
+; OPT-SAME: i32 [[TMP0:%.*]]) {
+; OPT-NEXT:    [[C:%.*]] = icmp ne i32 [[TMP0]], 0
+; OPT-NEXT:    br i1 [[C]], label %[[FALSE:.*]], label %[[FLOW:.*]]
+; OPT:       [[FLOW]]:
+; OPT-NEXT:    [[TMP2:%.*]] = phi i32 [ 33, %[[FALSE]] ], [ undef, [[TMP1:%.*]] ]
+; OPT-NEXT:    [[TMP3:%.*]] = phi i1 [ false, %[[FALSE]] ], [ true, [[TMP1]] ]
+; OPT-NEXT:    br i1 [[TMP3]], label %[[TRUE:.*]], label %[[EXIT:.*]]
+; OPT:       [[TRUE]]:
+; OPT-NEXT:    br label %[[EXIT]]
+; OPT:       [[FALSE]]:
+; OPT-NEXT:    br label %[[FLOW]]
+; OPT:       [[EXIT]]:
+; OPT-NEXT:    [[RET:%.*]] = phi i32 [ [[TMP2]], %[[FLOW]] ], [ 42, %[[TRUE]] ]
+; OPT-NEXT:    ret i32 [[RET]]
+;
+  %c = icmp eq i32 %0, 0
+  br i1 %c, label %true, label %false, !prof !0
+
+true:                                             ; preds = %1
+  br label %exit
+
+false:                                            ; preds = %1
+  br label %exit
+
+exit:                                             ; preds = %false, %true
+  %ret = phi i32 [ 42, %true ], [ 33, %false ]
+  ret i32 %ret
+}
+
+define amdgpu_ps void @loop_if_break(i32 %n) {
+; OPT-LABEL: define amdgpu_ps void @loop_if_break(
+; OPT-SAME: i32 [[N:%.*]]) {
+; OPT-NEXT:  [[ENTRY:.*]]:
+; OPT-NEXT:    br label %[[LOOP:.*]]
+; OPT:       [[LOOP]]:
+; OPT-NEXT:    [[I:%.*]] = phi i32 [ [[N]], %[[ENTRY]] ], [ [[TMP0:%.*]], %[[FLOW:.*]] ]
+; OPT-NEXT:    [[C:%.*]] = icmp ugt i32 [[I]], 0
+; OPT-NEXT:    br i1 [[C]], label %[[LOOP_BODY:.*]], label %[[FLOW]]
+; OPT:       [[LOOP_BODY]]:
+; OPT-NEXT:    [[I_NEXT:%.*]] = sub i32 [[I]], 1
+; OPT-NEXT:    br label %[[FLOW]]
+; OPT:       [[FLOW]]:
+; OPT-NEXT:    [[TMP0]] = phi i32 [ [[I_NEXT]], %[[LOOP_BODY]] ], [ undef, %[[LOOP]] ]
+; OPT-NEXT:    [[TMP1:%.*]] = phi i1 [ false, %[[LOOP_BODY]] ], [ true, %[[LOOP]] ]
+; OPT-NEXT:    br i1 [[TMP1]], label %[[EXIT:.*]], label %[[LOOP]]
+; OPT:       [[EXIT]]:
+; OPT-NEXT:    ret void
+;
+entry:
+  br label %loop
+
+loop:                                             ; preds = %loop_body, %entry
+  %i = phi i32 [ %n, %entry ], [ %i.next, %loop_body ]
+  %c = icmp ugt i32 %i, 0
+  br i1 %c, label %loop_body, label %exit, !prof !0
+
+loop_body:                                        ; preds = %loop
+  %i.next = sub i32 %i, 1
+  br label %loop
+
+exit:                                             ; preds = %loop
+  ret void
+}
+
+attributes #0 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }
+
+!0 = !{!"branch_weights", i32 1000, i32 1}