[clang codegen] Precommit tests for PR96025, NFC (#98704)

Add extern "C" for the function because there is difference function naming rules between Linux and Windows

Author: vfdff

clang/test/CodeGen/math-libcalls-tbaa.cpp

@@ -0,0 +1,38 @@
+// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py UTC_ARGS: --version 5
+
+// RUN:  %clang_cc1 -fmath-errno -O3 -emit-llvm -o - -x c++ %s | FileCheck %s -check-prefixes=CHECK,NoNewStructPathTBAA
+// RUN:  %clang_cc1 -fmath-errno -O3 -new-struct-path-tbaa -emit-llvm -o - -x c++ %s | FileCheck %s -check-prefixes=CHECK,NewStructPathTBAA
+
+extern "C" float expf(float);
+
+// Emit int TBAA metadata on FP math libcalls, which is useful for alias analysis
+
+// CHECK-LABEL: define dso_local float @foo(
+// CHECK-SAME: ptr nocapture noundef readonly [[NUM:%.*]], float noundef [[R2INV:%.*]], i32 noundef [[N:%.*]]) local_unnamed_addr #[[ATTR0:[0-9]+]] {
+// CHECK-NEXT:  [[ENTRY:.*:]]
+// CHECK-NEXT:    [[ARRAYIDX:%.*]] = getelementptr inbounds i8, ptr [[NUM]], i64 40
+// CHECK-NEXT:    [[TMP0:%.*]] = load float, ptr [[ARRAYIDX]], align 4, !tbaa [[TBAA2:![0-9]+]]
+// CHECK-NEXT:    [[CALL:%.*]] = tail call float @expf(float noundef [[TMP0]]) #[[ATTR2:[0-9]+]]
+// CHECK-NEXT:    [[TMP1:%.*]] = load float, ptr [[ARRAYIDX]], align 4, !tbaa [[TBAA2]]
+// CHECK-NEXT:    [[MUL:%.*]] = fmul float [[CALL]], [[TMP1]]
+// CHECK-NEXT:    ret float [[MUL]]
+//
+extern "C" float foo (float num[], float r2inv, int n) {
+   const float expm2 =  expf(num[10]);  // Emit TBAA metadata on @expf
+   float tmp = expm2 * num[10];
+   return tmp;
+}
+//.
+// NoNewStructPathTBAA: [[TBAA2]] = !{[[META3:![0-9]+]], [[META3]], i64 0}
+// NoNewStructPathTBAA: [[META3]] = !{!"float", [[META4:![0-9]+]], i64 0}
+// NoNewStructPathTBAA: [[META4]] = !{!"omnipotent char", [[META5:![0-9]+]], i64 0}
+// NoNewStructPathTBAA: [[META5]] = !{!"Simple C++ TBAA"}
+//.
+// NewStructPathTBAA: [[TBAA2]] = !{[[META3:![0-9]+]], [[META3]], i64 0, i64 4}
+// NewStructPathTBAA: [[META3]] = !{[[META4:![0-9]+]], i64 4, !"float"}
+// NewStructPathTBAA: [[META4]] = !{[[META5:![0-9]+]], i64 1, !"omnipotent char"}
+// NewStructPathTBAA: [[META5]] = !{!"Simple C++ TBAA"}
+//.
+//// NOTE: These prefixes are unused and the list is autogenerated. Do not add tests below this line:
+// NewStructPathTBAA: {{.*}}
+// NoNewStructPathTBAA: {{.*}}