commit 310deada107208511c1199d0580b9e3cdfbb45ca
author Alexei Starovoitov <alexei.starovoitov@gmail.com> Thu Jun 04 19:15:05 2015 +0000
committer Alexei Starovoitov <alexei.starovoitov@gmail.com> Thu Jun 04 19:15:05 2015 +0000
tree 0935bc73294e4addf7f01991c0db460bb3055293
parent 9ac8a6b13d998968226fdefb58ebd37eb3620ceb

[bpf] add big- and host- endian support

Summary:
-march=bpf    -> host endian
-march=bpf_le -> little endian
-match=bpf_be -> big endian

Test Plan:
v1 was tested by IBM s390 guys and appears to be working there.
It bit rots too fast here.

Reviewers: chandlerc, tstellarAMD

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D10177

llvm-svn: 239071

llvm/lib/Target/BPF/MCTargetDesc/BPFAsmBackend.cpp

diff --git a/llvm/lib/Target/BPF/MCTargetDesc/BPFAsmBackend.cpp b/llvm/lib/Target/BPF/MCTargetDesc/BPFAsmBackend.cpp
index 48f34e4..3398786 100644
--- a/llvm/lib/Target/BPF/MCTargetDesc/BPFAsmBackend.cpp
+++ b/llvm/lib/Target/BPF/MCTargetDesc/BPFAsmBackend.cpp
@@ -25,7 +25,10 @@
 namespace {
 class BPFAsmBackend : public MCAsmBackend {
 public:
-  BPFAsmBackend() : MCAsmBackend() {}
+  bool IsLittleEndian;
+
+  BPFAsmBackend(bool IsLittleEndian)
+    : MCAsmBackend(), IsLittleEndian(IsLittleEndian) {}
   ~BPFAsmBackend() override {}
 
   void applyFixup(const MCFixup &Fixup, char *Data, unsigned DataSize,
@@ -69,17 +72,28 @@
   }
   assert(Fixup.getKind() == FK_PCRel_2);
   Value = (uint16_t)((Value - 8) / 8);
-  Data[Fixup.getOffset() + 2] = Value & 0xFF;
-  Data[Fixup.getOffset() + 3] = Value >> 8;
+  if (IsLittleEndian) {
+    Data[Fixup.getOffset() + 2] = Value & 0xFF;
+    Data[Fixup.getOffset() + 3] = Value >> 8;
+  } else {
+    Data[Fixup.getOffset() + 2] = Value >> 8;
+    Data[Fixup.getOffset() + 3] = Value & 0xFF;
+  }
 }
 
 MCObjectWriter *BPFAsmBackend::createObjectWriter(raw_pwrite_stream &OS) const {
-  return createBPFELFObjectWriter(OS, 0);
+  return createBPFELFObjectWriter(OS, 0, IsLittleEndian);
 }
 }
 
 MCAsmBackend *llvm::createBPFAsmBackend(const Target &T,
                                         const MCRegisterInfo &MRI, StringRef TT,
                                         StringRef CPU) {
-  return new BPFAsmBackend();
+  return new BPFAsmBackend(/*IsLittleEndian=*/true);
+}
+
+MCAsmBackend *llvm::createBPFbeAsmBackend(const Target &T,
+                                          const MCRegisterInfo &MRI, StringRef TT,
+                                          StringRef CPU) {
+  return new BPFAsmBackend(/*IsLittleEndian=*/false);
 }