mips-force-nomadd4

The MIPS port aims to support the Loongson 3 family of CPUs in addition
of the other MIPS CPUs. On the Loongson 3 family the MADD4 instructions
are fused, while they are not fused on the other MIPS CPUs. In order to
support both, we have to disabled those instructions.

For that, the patch below basically corresponds to the --with-madd4=no
used on the GCC side.

Gbp-Pq: Topic mips
Gbp-Pq: Name mips-force-nomadd4.patch

diff --git a/clang/lib/Basic/Targets/Mips.h b/clang/lib/Basic/Targets/Mips.h
index b475c03889a177c75738dd3a90d5b7bb9973c95f..7ceaf031b6fc9df60db7ce9b7c923af88fd61cac 100644 (file)
--- a/clang/lib/Basic/Targets/Mips.h
+++ b/clang/lib/Basic/Targets/Mips.h
@@ -332,6 +332,8 @@ public:
         HasMSA = true;
       else if (Feature == "+nomadd4")
         DisableMadd4 = true;
+      else if (Feature == "-nomadd4")
+        DisableMadd4 = false;
       else if (Feature == "+fp64")
         FPMode = FP64;
       else if (Feature == "-fp64")

diff --git a/llvm/lib/Target/Mips/MipsSubtarget.cpp b/llvm/lib/Target/Mips/MipsSubtarget.cpp
index 8bb9d75e9173ad943f38c1fb6621d4573449fec0..75a3e19d2b0921c9b744a6e686998b23af4d9403 100644 (file)
--- a/llvm/lib/Target/Mips/MipsSubtarget.cpp
+++ b/llvm/lib/Target/Mips/MipsSubtarget.cpp
@@ -80,7 +80,7 @@ MipsSubtarget::MipsSubtarget(const Triple &TT, StringRef CPU, StringRef FS,
       InMips16HardFloat(Mips16HardFloat), InMicroMipsMode(false), HasDSP(false),
       HasDSPR2(false), HasDSPR3(false), AllowMixed16_32(Mixed16_32 | Mips_Os16),
       Os16(Mips_Os16), HasMSA(false), UseTCCInDIV(false), HasSym32(false),
-      HasEVA(false), DisableMadd4(false), HasMT(false), HasCRC(false),
+      HasEVA(false), DisableMadd4(true), HasMT(false), HasCRC(false),
       HasVirt(false), HasGINV(false), UseIndirectJumpsHazard(false),
       StackAlignOverride(StackAlignOverride), TM(TM), TargetTriple(TT),
       TSInfo(), InstrInfo(MipsInstrInfo::create(
@@ -91,6 +91,9 @@ MipsSubtarget::MipsSubtarget(const Triple &TT, StringRef CPU, StringRef FS,
   if (MipsArchVersion == MipsDefault)
     MipsArchVersion = Mips32;
 
+  if (hasMips32r6() || hasMips64r6())
+    DisableMadd4 = false;
+
   // Don't even attempt to generate code for MIPS-I and MIPS-V. They have not
   // been tested and currently exist for the integrated assembler only.
   if (MipsArchVersion == Mips1)
@@ -238,6 +241,7 @@ MipsSubtarget &
 MipsSubtarget::initializeSubtargetDependencies(StringRef CPU, StringRef FS,
                                                const TargetMachine &TM) {
   StringRef CPUName = MIPS_MC::selectMipsCPU(TM.getTargetTriple(), CPU);
+  SubtargetFeatures Features(FS);
 
   // Parse features string.
   ParseSubtargetFeatures(CPUName, /*TuneCPU*/ CPUName, FS);
@@ -260,6 +264,13 @@ MipsSubtarget::initializeSubtargetDependencies(StringRef CPU, StringRef FS,
     report_fatal_error("64-bit code requested on a subtarget that doesn't "
                        "support it!");
 
+  for (const std::string &Feature : Features.getFeatures()) {
+    if (Feature == "+nomadd4")
+      DisableMadd4 = true;
+    else if (Feature == "-nomadd4")
+      DisableMadd4 = false;
+  }
+
   return *this;
 }