[mips] Emit .reloc R_{MICRO}MIPS_JALR along with j(al)r(c) $25

The callee address is added as an optional operand (MCSymbol) in
AdjustInstrPostInstrSelection() and then used by asm printer to insert:
'.reloc tmplabel, R_MIPS_JALR, symbol
tmplabel:'.
Controlled with '-mips-jalr-reloc', default is true.

Differential revision: https://reviews.llvm.org/D56694

llvm-svn: 351485

1 files changed, 13 insertions, 0 deletions

diff --git a/llvm/lib/Target/Mips/MipsFastISel.cpp b/llvm/lib/Target/Mips/MipsFastISel.cpp
index 22ade31a72c..a18416b9e86 100644
--- a/llvm/lib/Target/Mips/MipsFastISel.cpp
+++ b/llvm/lib/Target/Mips/MipsFastISel.cpp
@@ -56,6 +56,7 @@
 #include "llvm/IR/Type.h"
 #include "llvm/IR/User.h"
 #include "llvm/IR/Value.h"
+#include "llvm/MC/MCContext.h"
 #include "llvm/MC/MCInstrDesc.h"
 #include "llvm/MC/MCRegisterInfo.h"
 #include "llvm/MC/MCSymbol.h"
@@ -75,6 +76,8 @@
 
 using namespace llvm;
 
+extern cl::opt<bool> EmitJalrReloc;
+
 namespace {
 
 class MipsFastISel final : public FastISel {
@@ -1551,6 +1554,16 @@ bool MipsFastISel::fastLowerCall(CallLoweringInfo &CLI) {
 
   CLI.Call = MIB;
 
+  if (EmitJalrReloc && !Subtarget->inMips16Mode()) {
+    // Attach callee address to the instruction, let asm printer emit
+    // .reloc R_MIPS_JALR.
+    if (Symbol)
+      MIB.addSym(Symbol, MipsII::MO_JALR);
+    else
+      MIB.addSym(FuncInfo.MF->getContext().getOrCreateSymbol(
+	                   Addr.getGlobalValue()->getName()), MipsII::MO_JALR);
+  }
+
   // Finish off the call including any return values.
   return finishCall(CLI, RetVT, NumBytes);
 }