[mips] Do not emit '.module [no]oddspreg' unless we really need to.

We now emit this directive when we need to contradict the default value (e.g.
-mno-odd-spreg is given) or an option changed the default value (e.g. -mfpxx
is given).

This restores support for the currently available head of binutils. However,
at this point binutils 2.24 is still not sufficient since it does not support
'.module fp=...'.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213511 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/Mips/MipsAsmPrinter.cpp

@@ -710,9 +710,14 @@ void MipsAsmPrinter::EmitStartOfAsmFile(Module &M) {
   getTargetStreamer().updateABIInfo(*Subtarget);
   getTargetStreamer().emitDirectiveModuleFP();
 
-  if (Subtarget->isABI_O32())
-    getTargetStreamer().emitDirectiveModuleOddSPReg(Subtarget->useOddSPReg(),
-                                                    Subtarget->isABI_O32());
+  // If we are targeting O32 then we must emit a '.module [no]oddspreg' ...
+  if (Subtarget->isABI_O32()) {
+    // ... but don't emit it unless we are contradicting the default or an
+    // option has changed the default (i.e. FPXX).
+    if (!Subtarget->useOddSPReg() || Subtarget->isABI_FPXX())
+      getTargetStreamer().emitDirectiveModuleOddSPReg(Subtarget->useOddSPReg(),
+                                                      Subtarget->isABI_O32());
+  }
 }
 
 void MipsAsmPrinter::EmitJal(MCSymbol *Symbol) {

test/CodeGen/Mips/no-odd-spreg.ll

@@ -1,10 +1,14 @@
-; RUN: llc -march=mipsel -mcpu=mips32 < %s | FileCheck %s -check-prefix=ALL -check-prefix=ODDSPREG
+; RUN: llc -march=mipsel -mcpu=mips32 < %s | FileCheck %s -check-prefix=ALL -check-prefix=ODDSPREG -check-prefix=ODDSPREG-NO-EMIT
 ; RUN: llc -march=mipsel -mcpu=mips32 -mattr=+nooddspreg < %s | FileCheck %s -check-prefix=ALL -check-prefix=NOODDSPREG
-; RUN: llc -march=mipsel -mcpu=mips32r6 -mattr=fp64 < %s | FileCheck %s -check-prefix=ALL -check-prefix=ODDSPREG
+; RUN: llc -march=mipsel -mcpu=mips32r6 -mattr=fp64 < %s | FileCheck %s -check-prefix=ALL -check-prefix=ODDSPREG -check-prefix=ODDSPREG-NO-EMIT
 ; RUN: llc -march=mipsel -mcpu=mips32r6 -mattr=fp64,+nooddspreg < %s | FileCheck %s -check-prefix=ALL -check-prefix=NOODDSPREG
+; RUN: llc -march=mipsel -mcpu=mips32r6 -mattr=fpxx,-nooddspreg < %s | FileCheck %s -check-prefix=ALL -check-prefix=ODDSPREG -check-prefix=ODDSPREG-EMIT
 
-; ODDSPREG:       .module oddspreg
-; NOODDSPREG:     .module nooddspreg
+; We don't emit a directive unless we need to. This is to support versions of
+; GAS which do not support the directive.
+; ODDSPREG-EMIT:        .module oddspreg
+; ODDSPREG-NO-EMIT-NOT: .module oddspreg
+; NOODDSPREG:           .module nooddspreg
 
 define float @two_floats(float %a) {
 entry: