ARM: Avoid adding default libcalls overridden by AEABI functions

Avoids adding alternative libcall impls for the same libcall.

I'm not sure if the default names exist or not, or are just not
preferred. compiler-rt appears to define aliases for all of these,
so I'm not sure why we bother distinguishing these in the first place.

Author: arsenm

llvm/include/llvm/IR/RuntimeLibcalls.td

@@ -1508,6 +1508,41 @@ def __aeabi_ddiv : RuntimeLibcallImpl<DIV_F64>; // CallingConv::ARM_AAPCS
 def __aeabi_dmul : RuntimeLibcallImpl<MUL_F64>; // CallingConv::ARM_AAPCS
 def __aeabi_dsub : RuntimeLibcallImpl<SUB_F64>; // CallingConv::ARM_AAPCS
 
+defvar AEABIOverrides = [
+  __eqsf2, __eqdf2,
+  __nesf2, __nedf2,
+  __ltsf2, __ltdf2,
+  __lesf2, __ledf2,
+  __gesf2, __gedf2,
+  __gtsf2, __gtdf2,
+  __unordsf2, __unorddf2,
+
+  __addsf3, __adddf3,
+  __divsf3, __divdf3,
+  __mulsf3, __muldf3,
+  __subsf3, __subdf3,
+
+  __fixdfsi, __fixunsdfsi,
+  __fixdfdi, __fixunsdfdi,
+  __fixsfsi, __fixunssfsi,
+  __fixsfdi, __fixunssfdi,
+
+  __floatsidf, __floatunsidf,
+  __floatdidf, __floatundidf,
+  __floatsisf, __floatunsisf,
+  __floatdisf, __floatundisf,
+
+  __muldi3, __ashldi3,
+  __lshrdi3, __ashrdi3,
+
+  __divsi3, __udivsi3
+
+  // Half conversion cases are a mess and handled separately.
+  //  __truncdfsf2, __truncdfhf2,
+  //  __extendsfdf2,
+  //  __truncsfhf2, __extendhfsf2
+];
+
 // Double-precision floating-point comparison helper functions
 // RTABI chapter 4.1.2, Table 3
 def __aeabi_dcmpeq__oeq : RuntimeLibcallImpl<OEQ_F64, "__aeabi_dcmpeq">; // CallingConv::ARM_AAPCS, CmpInst::ICMP_NE
@@ -1793,7 +1828,8 @@ def ARMSystemLibrary
     : SystemRuntimeLibrary<isARMOrThumb,
       (add (sub WinDefaultLibcallImpls, ARMLibgccHalfConvertCalls,
                                         GNUEABIHalfConvertCalls,
-                                        ARMDoubleToHalfCalls),
+                                        ARMDoubleToHalfCalls,
+                                        AEABIOverrides),
            LibcallImpls<(add __powisf2, __powidf2), isNotOSMSVCRT>,
            LibmHasFrexpF32, LibmHasLdexpF32,
            LibmHasFrexpF128, LibmHasLdexpF128,
@@ -1812,6 +1848,11 @@ def ARMSystemLibrary
            GNUEABIHalfConvertCalls,
            ARMDoubleToHalfCalls,
 
+           LibcallImpls<(add AEABIOverrides),
+             RuntimeLibcallPredicate<[{
+               (!hasAEABILibcalls(TT) || !isAAPCS_ABI(TT, ABIName)) &&
+               !TT.isOSWindows()
+            }]>>,
            // Use divmod compiler-rt calls for iOS 5.0 and later.
            LibcallImpls<(add __divmodsi4, __udivmodsi4),
                         RuntimeLibcallPredicate<[{TT.isOSBinFormatMachO() &&