Do not mention x86 floating point numbers in CFI.

We have explicitly declared them as undefined, but libunwind does
not seem to support them at all.  Omit the initialization to make
libunwind happy.  Reasonable debugger should still default to
undefined since they are not callee save registers.

Bug: 20491296
Change-Id: Ibaa9595b977508e518bfe3f88b240e8959b1198f

1 files changed, 6 insertions, 2 deletions

diff --git a/compiler/elf_writer_debug.cc b/compiler/elf_writer_debug.cc
index cf0adae525..28e6999472 100644
--- a/compiler/elf_writer_debug.cc
+++ b/compiler/elf_writer_debug.cc
@@ -99,6 +99,8 @@ static void WriteEhFrameCIE(InstructionSet isa,
       return;
     }
     case kX86: {
+      // FIXME: Add fp registers once libunwind adds support for them. Bug: 20491296
+      constexpr bool generate_opcodes_for_x86_fp = false;
       DebugFrameOpCodeWriter<> opcodes;
       opcodes.DefCFA(Reg::X86Core(4), 4);   // R4(ESP).
       opcodes.Offset(Reg::X86Core(8), -4);  // R8(EIP).
@@ -113,8 +115,10 @@ static void WriteEhFrameCIE(InstructionSet isa,
         }
       }
       // fp registers.
-      for (int reg = 0; reg < 8; reg++) {
-        opcodes.Undefined(Reg::X86Fp(reg));
+      if (generate_opcodes_for_x86_fp) {
+        for (int reg = 0; reg < 8; reg++) {
+          opcodes.Undefined(Reg::X86Fp(reg));
+        }
       }
       auto return_reg = Reg::X86Core(8);  // R8(EIP).
       WriteEhFrameCIE(is64bit, addr_type, return_reg, opcodes, eh_frame);