[llvm] [BOLT][RISCV] Handle static IFUNC calls through .iplt (PR #207733)

[via llvm-commits]

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@@ -1992,8 +2044,9 @@ void RewriteInstance::disassemblePLTSectionRISCV(BinarySection &Section) {
     }
   };
 
-  // Skip the first special entry since no relocation points to it.
-  uint64_t InstrOffset = 32;
+  // A regular RISC-V .plt starts with a 32-byte PLT0 header, while a
+  // standalone .iplt contains only 16-byte non-preemptible IFUNC entries.
+  uint64_t InstrOffset = Section.getName() == ".iplt" ? 0 : 32;
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WangJee wrote:

GNU ld can emit static IFUNC entries in a headerless .plt with R_RISCV_IRELATIVE relocations in .rela.plt. The current code always skips 32 bytes for .plt, and the static relocation fallback only discovers .rela.dyn?

https://github.com/llvm/llvm-project/pull/207733