[MC] Aligned bundling: remove special handling for RelaxAll

When both aligned bundling and RelaxAll are enabled, bundle padding is
directly written into fragments (https://reviews.llvm.org/D8072).
(The original motivation was memory usage, which has been achieved from
different angles with recent assembler improvement).

The code presents challenges with the work to replace fragment
representation (e.g. #94950 #95077). This patch removes the special
handling. RelaxAll still works but the behavior seems slightly different
as revealed by 2 changed tests. However, most `-mc-relax-all` tests are
unchanged.

RelaxAll used to be the default for clang -O0. This mode has significant
code size drawbacks and newer Clang doesn't use it (#90013).

---

flushPendingLabels: The FOffset parameter can be removed: pending labels
will be assigned to the incoming fragment at offset 0.

Pull Request: https://github.com/llvm/llvm-project/pull/95188

1 files changed, 3 insertions, 4 deletions

diff --git a/llvm/lib/MC/MCSection.cpp b/llvm/lib/MC/MCSection.cpp
index 59fdfd7..3a7a8a0 100644
--- a/llvm/lib/MC/MCSection.cpp
+++ b/llvm/lib/MC/MCSection.cpp
@@ -82,15 +82,14 @@ void MCSection::addPendingLabel(MCSymbol *label, unsigned Subsection) {
   PendingLabels.push_back(PendingLabel(label, Subsection));
 }
 
-void MCSection::flushPendingLabels(MCFragment *F, uint64_t FOffset,
-				   unsigned Subsection) {
+void MCSection::flushPendingLabels(MCFragment *F, unsigned Subsection) {
   // Set the fragment and fragment offset for all pending symbols in the
   // specified Subsection, and remove those symbols from the pending list.
   for (auto It = PendingLabels.begin(); It != PendingLabels.end(); ++It) {
     PendingLabel& Label = *It;
     if (Label.Subsection == Subsection) {
       Label.Sym->setFragment(F);
-      Label.Sym->setOffset(FOffset);
+      assert(Label.Sym->getOffset() == 0);
       PendingLabels.erase(It--);
     }
   }
@@ -105,7 +104,7 @@ void MCSection::flushPendingLabels() {
     MCFragment *F = new MCDataFragment();
     addFragment(*F);
     F->setParent(this);
-    flushPendingLabels(F, 0, Label.Subsection);
+    flushPendingLabels(F, Label.Subsection);
   }
 }