From 294ba569803972323a64670451a82af53c660541 Mon Sep 17 00:00:00 2001
From: Dimitry Andric <dim@FreeBSD.org>
Date: Sat, 27 Dec 2025 23:21:13 +0100
Subject: Vendor import of llvm-project branch release/21.x
 llvmorg-21.1.7-0-gcd708029e0b2, a.k.a. 21.1.7 release.

---
 .../Target/RISCV/MCTargetDesc/RISCVAsmBackend.cpp  | 42 +++++++++++++++++-----
 1 file changed, 33 insertions(+), 9 deletions(-)

(limited to 'llvm/lib/Target/RISCV/MCTargetDesc/RISCVAsmBackend.cpp')

diff --git a/llvm/lib/Target/RISCV/MCTargetDesc/RISCVAsmBackend.cpp b/llvm/lib/Target/RISCV/MCTargetDesc/RISCVAsmBackend.cpp
index e42d6c539a34..df3028e05139 100644
--- a/llvm/lib/Target/RISCV/MCTargetDesc/RISCVAsmBackend.cpp
+++ b/llvm/lib/Target/RISCV/MCTargetDesc/RISCVAsmBackend.cpp
@@ -792,6 +792,23 @@ void RISCVAsmBackend::maybeAddVendorReloc(const MCFragment &F,
   Asm->getWriter().recordRelocation(F, VendorFixup, VendorTarget, VendorValue);
 }
 
+static bool relaxableFixupNeedsRelocation(const MCFixupKind Kind) {
+  // Some Fixups are marked as LinkerRelaxable by
+  // `RISCVMCCodeEmitter::getImmOpValue` only because they may be
+  // (assembly-)relaxed into a linker-relaxable instruction. This function
+  // should return `false` for those fixups so they do not get a `R_RISCV_RELAX`
+  // relocation emitted in addition to the relocation.
+  switch (Kind) {
+  default:
+    break;
+  case RISCV::fixup_riscv_rvc_jump:
+  case RISCV::fixup_riscv_rvc_branch:
+  case RISCV::fixup_riscv_jal:
+    return false;
+  }
+  return true;
+}
+
 bool RISCVAsmBackend::addReloc(const MCFragment &F, const MCFixup &Fixup,
                                const MCValue &Target, uint64_t &FixedValue,
                                bool IsResolved) {
@@ -834,25 +851,32 @@ bool RISCVAsmBackend::addReloc(const MCFragment &F, const MCFixup &Fixup,
     return false;
   }
 
-  // If linker relaxation is enabled and supported by the current relocation,
-  // generate a relocation and then append a RELAX.
-  if (Fixup.isLinkerRelaxable())
+  // If linker relaxation is enabled and supported by the current fixup, then we
+  // always want to generate a relocation.
+  bool NeedsRelax = Fixup.isLinkerRelaxable() &&
+                    relaxableFixupNeedsRelocation(Fixup.getKind());
+  if (NeedsRelax)
     IsResolved = false;
+
   if (IsResolved && Fixup.isPCRel())
     IsResolved = isPCRelFixupResolved(Target.getAddSym(), F);
 
   if (!IsResolved) {
-    // Some Fixups require a vendor relocation, record it (directly) before we
+    // Some Fixups require a VENDOR relocation, record it (directly) before we
     // add the relocation.
     maybeAddVendorReloc(F, Fixup);
 
     Asm->getWriter().recordRelocation(F, Fixup, Target, FixedValue);
-  }
 
-  if (Fixup.isLinkerRelaxable()) {
-    auto FA = MCFixup::create(Fixup.getOffset(), nullptr, ELF::R_RISCV_RELAX);
-    Asm->getWriter().recordRelocation(F, FA, MCValue::get(nullptr),
-                                      FixedValueA);
+    if (NeedsRelax) {
+      // Some Fixups get a RELAX relocation, record it (directly) after we add
+      // the relocation.
+      MCFixup RelaxFixup =
+          MCFixup::create(Fixup.getOffset(), nullptr, ELF::R_RISCV_RELAX);
+      MCValue RelaxTarget = MCValue::get(nullptr);
+      uint64_t RelaxValue;
+      Asm->getWriter().recordRelocation(F, RelaxFixup, RelaxTarget, RelaxValue);
+    }
   }
 
   return false;
-- 
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