Slightly saner handling of thumb branches.
The generic infrastructure already did a lot of work to decide if the
fixup value is know or not. It doesn't make sense to reimplement a very
basic case: same fragment.
llvm-svn: 252090
diff --git a/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp b/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
index 9c9747f..fd678fb 100644
--- a/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
+++ b/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
@@ -620,6 +620,7 @@
const MCValue &Target, uint64_t &Value,
bool &IsResolved) {
const MCSymbolRefExpr *A = Target.getSymA();
+ const MCSymbol *Sym = A ? &A->getSymbol() : nullptr;
// Some fixups to thumb function symbols need the low bit (thumb bit)
// twiddled.
if ((unsigned)Fixup.getKind() != ARM::fixup_arm_ldst_pcrel_12 &&
@@ -628,18 +629,23 @@
(unsigned)Fixup.getKind() != ARM::fixup_thumb_adr_pcrel_10 &&
(unsigned)Fixup.getKind() != ARM::fixup_t2_adr_pcrel_12 &&
(unsigned)Fixup.getKind() != ARM::fixup_arm_thumb_cp) {
- if (A) {
- const MCSymbol &Sym = A->getSymbol();
- if (Asm.isThumbFunc(&Sym))
+ if (Sym) {
+ if (Asm.isThumbFunc(Sym))
Value |= 1;
}
}
- // For Thumb1 BL instruction, it is possible to be a long jump between
- // the basic blocks of the same function. Thus, we would like to resolve
- // the offset when the destination has the same MCFragment.
- if (A && (unsigned)Fixup.getKind() == ARM::fixup_arm_thumb_bl) {
- const MCSymbol &Sym = A->getSymbol();
- IsResolved = (Sym.getFragment() == DF);
+ if (IsResolved && (unsigned)Fixup.getKind() == ARM::fixup_arm_thumb_bl) {
+ assert(Sym && "How did we resolve this?");
+
+ // If the symbol is external the linker will handle it.
+ // FIXME: Should we handle it as an optimization?
+ if (Sym->isExternal()) {
+ IsResolved = false;
+ } else {
+ if (Value >= 0x400004)
+ Asm.getContext().reportFatalError(Fixup.getLoc(),
+ "out of range for branch");
+ }
}
// We must always generate a relocation for BL/BLX instructions if we have
// a symbol to reference, as the linker relies on knowing the destination