MC: Sketch some TargetAsmBackend hooks we are going to need.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98221 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm/Target/TargetAsmBackend.h b/include/llvm/Target/TargetAsmBackend.h
index dfdabdb..35e768c 100644
--- a/include/llvm/Target/TargetAsmBackend.h
+++ b/include/llvm/Target/TargetAsmBackend.h
@@ -28,6 +28,28 @@
const Target &getTarget() const { return TheTarget; }
+ /// hasAbsolutizedSet - Check whether this target "absolutizes"
+ /// assignments. That is, given code like:
+ /// a:
+ /// ...
+ /// b:
+ /// tmp = a - b
+ /// .long tmp
+ /// will the value of 'tmp' be a relocatable expression, or the assembly time
+ /// value of L0 - L1. This distinction is only relevant for platforms that
+ /// support scattered symbols, since in the absence of scattered symbols (a -
+ /// b) cannot change after assembly.
+ virtual bool hasAbsolutizedSet() const { return false; }
+
+ /// hasScatteredSymbols - Check whether this target supports scattered
+ /// symbols. If so, the assembler should assume that atoms can be scattered by
+ /// the linker. In particular, this means that the offsets between symbols
+ /// which are in distinct atoms is not known at link time, and the assembler
+ /// must generate fixups and relocations appropriately.
+ ///
+ /// Note that the assembler currently does not reason about atoms, instead it
+ /// assumes all temporary symbols reside in the "current atom".
+ virtual bool hasScatteredSymbols() const { return false; }
};
} // End llvm namespace
diff --git a/lib/Target/X86/X86AsmBackend.cpp b/lib/Target/X86/X86AsmBackend.cpp
index 2eda7b5..88cc2c7 100644
--- a/lib/Target/X86/X86AsmBackend.cpp
+++ b/lib/Target/X86/X86AsmBackend.cpp
@@ -21,14 +21,34 @@
: TargetAsmBackend(T) {}
};
+class DarwinX86AsmBackend : public X86AsmBackend {
+public:
+ DarwinX86AsmBackend(const Target &T)
+ : X86AsmBackend(T) {}
+
+ virtual bool hasAbsolutizedSet() const { return true; }
+
+ virtual bool hasScatteredSymbols() const { return true; }
+};
+
}
TargetAsmBackend *llvm::createX86_32AsmBackend(const Target &T,
const std::string &TT) {
- return new X86AsmBackend(T);
+ switch (Triple(TT).getOS()) {
+ case Triple::Darwin:
+ return new DarwinX86AsmBackend(T);
+ default:
+ return new X86AsmBackend(T);
+ }
}
TargetAsmBackend *llvm::createX86_64AsmBackend(const Target &T,
const std::string &TT) {
- return new X86AsmBackend(T);
+ switch (Triple(TT).getOS()) {
+ case Triple::Darwin:
+ return new DarwinX86AsmBackend(T);
+ default:
+ return new X86AsmBackend(T);
+ }
}