[EABI] Add LLVM support for -meabi flag

"GCC requires the freestanding environment provide memcpy, memmove, memset
and memcmp": https://gcc.gnu.org/onlinedocs/gcc-5.2.0/gcc/Standards.html

Hence in GNUEABI targets LLVM should not convert 'memops' to their equivalent
'__aeabi_memops'. This convertion violates GCC contract.

The -meabi flag controls whether or not LLVM will modify 'memops' in GNUEABI
targets.

Without -meabi: use the triple default EABI.
With -meabi=default: use the triple default EABI.
With -meabi=gnu: use 'memops'.
With -meabi=4 or -meabi=5: use '__aeabi_memops'.
With -meabi set to an unknown value: same as -meabi=default.

Patch by Vinicius Tinti.

llvm-svn: 252462

3 files changed, 42 insertions, 8 deletions

diff --git a/llvm/lib/Target/ARM/ARMISelLowering.cpp b/llvm/lib/Target/ARM/ARMISelLowering.cpp
index 8f9ca96e5d9..f6a382b44fc 100644
--- a/llvm/lib/Target/ARM/ARMISelLowering.cpp
+++ b/llvm/lib/Target/ARM/ARMISelLowering.cpp
@@ -256,8 +256,10 @@ ARMTargetLowering::ARMTargetLowering(const TargetMachine &TM,
   setLibcallName(RTLIB::SRL_I128, nullptr);
   setLibcallName(RTLIB::SRA_I128, nullptr);
 
-  if (Subtarget->isAAPCS_ABI() && !Subtarget->isTargetMachO() &&
-      !Subtarget->isTargetWindows()) {
+  // RTLIB
+  if (Subtarget->isAAPCS_ABI() &&
+      (Subtarget->isTargetAEABI() || Subtarget->isTargetGNUAEABI() ||
+       Subtarget->isTargetAndroid())) {
     static const struct {
       const RTLIB::Libcall Op;
       const char * const Name;
@@ -345,12 +347,6 @@ ARMTargetLowering::ARMTargetLowering(const TargetMachine &TM,
       { RTLIB::UDIV_I16, "__aeabi_uidiv",    CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
       { RTLIB::UDIV_I32, "__aeabi_uidiv",    CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
       { RTLIB::UDIV_I64, "__aeabi_uldivmod", CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
-
-      // Memory operations
-      // RTABI chapter 4.3.4
-      { RTLIB::MEMCPY,  "__aeabi_memcpy",  CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
-      { RTLIB::MEMMOVE, "__aeabi_memmove", CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
-      { RTLIB::MEMSET,  "__aeabi_memset",  CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
     };
 
     for (const auto &LC : LibraryCalls) {
@@ -359,6 +355,30 @@ ARMTargetLowering::ARMTargetLowering(const TargetMachine &TM,
       if (LC.Cond != ISD::SETCC_INVALID)
         setCmpLibcallCC(LC.Op, LC.Cond);
     }
+
+    // EABI dependent RTLIB
+    if (TM.Options.EABIVersion == EABI::EABI4 ||
+        TM.Options.EABIVersion == EABI::EABI5) {
+      static const struct {
+        const RTLIB::Libcall Op;
+        const char *const Name;
+        const CallingConv::ID CC;
+        const ISD::CondCode Cond;
+      } MemOpsLibraryCalls[] = {
+        // Memory operations
+        // RTABI chapter 4.3.4
+        { RTLIB::MEMCPY,  "__aeabi_memcpy",  CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
+        { RTLIB::MEMMOVE, "__aeabi_memmove", CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
+        { RTLIB::MEMSET,  "__aeabi_memset",  CallingConv::ARM_AAPCS, ISD::SETCC_INVALID },
+      };
+
+      for (const auto &LC : MemOpsLibraryCalls) {
+        setLibcallName(LC.Op, LC.Name);
+        setLibcallCallingConv(LC.Op, LC.CC);
+        if (LC.Cond != ISD::SETCC_INVALID)
+          setCmpLibcallCC(LC.Op, LC.Cond);
+      }
+    }
   }
 
   if (Subtarget->isTargetWindows()) {
diff --git a/llvm/lib/Target/ARM/ARMSubtarget.h b/llvm/lib/Target/ARM/ARMSubtarget.h
index 66b56d10faa..530aa63fff4 100644
--- a/llvm/lib/Target/ARM/ARMSubtarget.h
+++ b/llvm/lib/Target/ARM/ARMSubtarget.h
@@ -380,6 +380,11 @@ public:
             TargetTriple.getEnvironment() == Triple::EABIHF) &&
            !isTargetDarwin() && !isTargetWindows();
   }
+  bool isTargetGNUAEABI() const {
+    return (TargetTriple.getEnvironment() == Triple::GNUEABI ||
+            TargetTriple.getEnvironment() == Triple::GNUEABIHF) &&
+           !isTargetDarwin() && !isTargetWindows();
+  }
 
   // ARM Targets that support EHABI exception handling standard
   // Darwin uses SjLj. Other targets might need more checks.
diff --git a/llvm/lib/Target/ARM/ARMTargetMachine.cpp b/llvm/lib/Target/ARM/ARMTargetMachine.cpp
index 9a5efc8d0b9..fca1901dc57 100644
--- a/llvm/lib/Target/ARM/ARMTargetMachine.cpp
+++ b/llvm/lib/Target/ARM/ARMTargetMachine.cpp
@@ -188,6 +188,15 @@ ARMBaseTargetMachine::ARMBaseTargetMachine(const Target &T, const Triple &TT,
   if (Options.FloatABIType == FloatABI::Default)
     this->Options.FloatABIType =
         Subtarget.isTargetHardFloat() ? FloatABI::Hard : FloatABI::Soft;
+
+  // Default to triple-appropriate EABI
+  if (Options.EABIVersion == EABI::Default ||
+      Options.EABIVersion == EABI::Unknown) {
+    if (Subtarget.isTargetGNUAEABI())
+      this->Options.EABIVersion = EABI::GNU;
+    else
+      this->Options.EABIVersion = EABI::EABI5;
+  }
 }
 
 ARMBaseTargetMachine::~ARMBaseTargetMachine() {}