[mips] Add initial support for NaN2008 in the back-end.

This is so that EF_MIPS_NAN2008 is set if we are using IEEE 754-2008
NaN encoding (-mnan=2008). This patch also adds support for parsing
'.nan legacy' and '.nan 2008' assembly directives. The handling of
these directives should match GAS' behaviour i.e., the last directive
in use sets the ELF header bit (EF_MIPS_NAN2008).

Differential Revision: http://reviews.llvm.org/D3346


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206396 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 26 insertions, 0 deletions

diff --git a/lib/Target/Mips/MCTargetDesc/MipsTargetStreamer.cpp b/lib/Target/Mips/MCTargetDesc/MipsTargetStreamer.cpp
index fb6aff2b0d..053e13e556 100644
--- a/lib/Target/Mips/MCTargetDesc/MipsTargetStreamer.cpp
+++ b/lib/Target/Mips/MCTargetDesc/MipsTargetStreamer.cpp
@@ -85,6 +85,13 @@ void MipsTargetAsmStreamer::emitDirectiveEnt(const MCSymbol &Symbol) {
 }
 
 void MipsTargetAsmStreamer::emitDirectiveAbiCalls() { OS << "\t.abicalls\n"; }
+
+void MipsTargetAsmStreamer::emitDirectiveNaN2008() { OS << "\t.nan\t2008\n"; }
+
+void MipsTargetAsmStreamer::emitDirectiveNaNLegacy() {
+  OS << "\t.nan\tlegacy\n";
+}
+
 void MipsTargetAsmStreamer::emitDirectiveOptionPic0() {
   OS << "\t.option\tpic0\n";
 }
@@ -180,6 +187,10 @@ MipsTargetELFStreamer::MipsTargetELFStreamer(MCStreamer &S,
     EFlags |= ELF::EF_MIPS_ABI_O32;
   }
 
+  // Other options.
+  if (Features & Mips::FeatureNaN2008)
+    EFlags |= ELF::EF_MIPS_NAN2008;
+
   MCA.setELFHeaderEFlags(EFlags);
 }
 
@@ -325,6 +336,21 @@ void MipsTargetELFStreamer::emitDirectiveAbiCalls() {
   Flags |= ELF::EF_MIPS_CPIC | ELF::EF_MIPS_PIC;
   MCA.setELFHeaderEFlags(Flags);
 }
+
+void MipsTargetELFStreamer::emitDirectiveNaN2008() {
+  MCAssembler &MCA = getStreamer().getAssembler();
+  unsigned Flags = MCA.getELFHeaderEFlags();
+  Flags |= ELF::EF_MIPS_NAN2008;
+  MCA.setELFHeaderEFlags(Flags);
+}
+
+void MipsTargetELFStreamer::emitDirectiveNaNLegacy() {
+  MCAssembler &MCA = getStreamer().getAssembler();
+  unsigned Flags = MCA.getELFHeaderEFlags();
+  Flags &= ~ELF::EF_MIPS_NAN2008;
+  MCA.setELFHeaderEFlags(Flags);
+}
+
 void MipsTargetELFStreamer::emitDirectiveOptionPic0() {
   MCAssembler &MCA = getStreamer().getAssembler();
   unsigned Flags = MCA.getELFHeaderEFlags();