[llvm] [BasicBlockSections] Allow mixing of -basic-block-sections with MFS. (PR #117076)

[Snehasish Kumar via llvm-commits]

================
@@ -610,6 +620,63 @@ cold_asm_target:
   ret void
 }
 
+define void @foo21(i1 zeroext %0) {
+;; Check that a function with basic-block-sections profile (but no pgo profile)
+;; is properly split when the profile is used along with mfs.
+; MFS-BBSECTIONS:            .section   .text.hot.foo21
+; MFS-NOBBSECTIONS-NOT:      .section   .text.hot.foo21
+; MFS-BBSECTIONS-LABEL:      foo21:
+; MFS-NOBBSECTIONS-NOT:      foo21.cold:
+; MFS-BBSECTIONS:            .section	.text.split.foo21
+; MFS-BBSECTIONS:            foo21.cold
+  %2 = alloca i8, align 1
+  %3 = zext i1 %0 to i8
+  store i8 %3, ptr %2, align 1
+  %4 = load i8, ptr %2, align 1
+  %5 = trunc i8 %4 to i1
+  br i1 %5, label %6, label %8
+
+6:                                                ; preds = %1
+  %7 = call i32 @bar()
+  br label %10
+
+8:                                                ; preds = %1
+  %9 = call i32 @baz()
+  br label %10
+
+10:                                               ; preds = %8, %6
+  ret void
+}
+
+define void @foo22(i1 zeroext %0) nounwind !prof !14 !section_prefix !15 {
+;; Check that when a function has both basic-block-section and pgo profiles
+;; only the basic-block-section profile is used for splitting.
+
+;; Check that we create two hot sections with -basic-block-sections.
+; MFS-BBSECTIONS:             .section        .text.hot.foo22
+; MFS-BBSECTIONS-LABEL:       foo22:
+; MFS-BBSECTIONS:             callq  bar
+; MFS-BBSECTIONS:             .section        .text.hot.foo22
+; MFS-BBSECTIONS-NEXT:        foo22.__part.1:
+; MFS-BBSECTIONS:             callq  baz
+; MFS-BBSECTIONS-NOT:         .section        .text.split.foo22
+  br i1 %0, label %2, label %4, !prof !17
+
+2:                                                ; preds = %1
+  %3 = call i32 @bar()
+  br label %6
+
+4:                                                ; preds = %1
+  %5 = call i32 @baz()
+  br label %6
+
+6:                                                ; preds = %4, %2
+  %7 = tail call i32 @qux()
+  ret void
+}
+
+
----------------
snehasish wrote:

Unnecessary new lines?

https://github.com/llvm/llvm-project/pull/117076