1 //===---- MipsCCState.cpp - CCState with Mips specific extensions ---------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "MipsCCState.h"
11 #include "MipsSubtarget.h"
12 #include "llvm/IR/Module.h"
13 
14 using namespace llvm;
15 
16 /// This function returns true if CallSym is a long double emulation routine.
17 static bool isF128SoftLibCall(const char *CallSym) {
18   const char *const LibCalls[] = {
19       "__addtf3",      "__divtf3",     "__eqtf2",       "__extenddftf2",
20       "__extendsftf2", "__fixtfdi",    "__fixtfsi",     "__fixtfti",
21       "__fixunstfdi",  "__fixunstfsi", "__fixunstfti",  "__floatditf",
22       "__floatsitf",   "__floattitf",  "__floatunditf", "__floatunsitf",
23       "__floatuntitf", "__getf2",      "__gttf2",       "__letf2",
24       "__lttf2",       "__multf3",     "__netf2",       "__powitf2",
25       "__subtf3",      "__trunctfdf2", "__trunctfsf2",  "__unordtf2",
26       "ceill",         "copysignl",    "cosl",          "exp2l",
27       "expl",          "floorl",       "fmal",          "fmodl",
28       "log10l",        "log2l",        "logl",          "nearbyintl",
29       "powl",          "rintl",        "roundl",        "sinl",
30       "sqrtl",         "truncl"};
31 
32   // Check that LibCalls is sorted alphabetically.
33   auto Comp = [](const char *S1, const char *S2) { return strcmp(S1, S2) < 0; };
34   assert(std::is_sorted(std::begin(LibCalls), std::end(LibCalls), Comp));
35   return std::binary_search(std::begin(LibCalls), std::end(LibCalls),
36                             CallSym, Comp);
37 }
38 
39 /// This function returns true if Ty is fp128, {f128} or i128 which was
40 /// originally a fp128.
41 static bool originalTypeIsF128(const Type *Ty, const char *Func) {
42   if (Ty->isFP128Ty())
43     return true;
44 
45   if (Ty->isStructTy() && Ty->getStructNumElements() == 1 &&
46       Ty->getStructElementType(0)->isFP128Ty())
47     return true;
48 
49   // If the Ty is i128 and the function being called is a long double emulation
50   // routine, then the original type is f128.
51   return (Func && Ty->isIntegerTy(128) && isF128SoftLibCall(Func));
52 }
53 
54 MipsCCState::SpecialCallingConvType
55 MipsCCState::getSpecialCallingConvForCallee(const SDNode *Callee,
56                                             const MipsSubtarget &Subtarget) {
57   MipsCCState::SpecialCallingConvType SpecialCallingConv = NoSpecialCallingConv;
58   if (Subtarget.inMips16HardFloat()) {
59     if (const GlobalAddressSDNode *G =
60             dyn_cast<const GlobalAddressSDNode>(Callee)) {
61       llvm::StringRef Sym = G->getGlobal()->getName();
62       Function *F = G->getGlobal()->getParent()->getFunction(Sym);
63       if (F && F->hasFnAttribute("__Mips16RetHelper")) {
64         SpecialCallingConv = Mips16RetHelperConv;
65       }
66     }
67   }
68   return SpecialCallingConv;
69 }
70 
71 void MipsCCState::PreAnalyzeCallResultForF128(
72     const SmallVectorImpl<ISD::InputArg> &Ins,
73     const Type *RetTy, const char *Call) {
74   for (unsigned i = 0; i < Ins.size(); ++i) {
75     OriginalArgWasF128.push_back(
76         originalTypeIsF128(RetTy, Call));
77     OriginalArgWasFloat.push_back(RetTy->isFloatingPointTy());
78   }
79 }
80 
81 /// Identify lowered values that originated from f128 arguments and record
82 /// this for use by RetCC_MipsN.
83 void MipsCCState::PreAnalyzeReturnForF128(
84     const SmallVectorImpl<ISD::OutputArg> &Outs) {
85   const MachineFunction &MF = getMachineFunction();
86   for (unsigned i = 0; i < Outs.size(); ++i) {
87     OriginalArgWasF128.push_back(
88         originalTypeIsF128(MF.getFunction()->getReturnType(), nullptr));
89     OriginalArgWasFloat.push_back(
90         MF.getFunction()->getReturnType()->isFloatingPointTy());
91   }
92 }
93 
94 /// Identify lowered values that originated from f128 arguments and record
95 /// this.
96 void MipsCCState::PreAnalyzeCallOperands(
97     const SmallVectorImpl<ISD::OutputArg> &Outs,
98     std::vector<TargetLowering::ArgListEntry> &FuncArgs,
99     const char *Func) {
100   for (unsigned i = 0; i < Outs.size(); ++i) {
101     OriginalArgWasF128.push_back(
102         originalTypeIsF128(FuncArgs[Outs[i].OrigArgIndex].Ty, Func));
103     OriginalArgWasFloat.push_back(
104         FuncArgs[Outs[i].OrigArgIndex].Ty->isFloatingPointTy());
105     CallOperandIsFixed.push_back(Outs[i].IsFixed);
106   }
107 }
108 
109 /// Identify lowered values that originated from f128 arguments and record
110 /// this.
111 void MipsCCState::PreAnalyzeFormalArgumentsForF128(
112     const SmallVectorImpl<ISD::InputArg> &Ins) {
113   const MachineFunction &MF = getMachineFunction();
114   for (unsigned i = 0; i < Ins.size(); ++i) {
115     Function::const_arg_iterator FuncArg = MF.getFunction()->arg_begin();
116 
117     // SRet arguments cannot originate from f128 or {f128} returns so we just
118     // push false. We have to handle this specially since SRet arguments
119     // aren't mapped to an original argument.
120     if (Ins[i].Flags.isSRet()) {
121       OriginalArgWasF128.push_back(false);
122       OriginalArgWasFloat.push_back(false);
123       continue;
124     }
125 
126     assert(Ins[i].getOrigArgIndex() < MF.getFunction()->arg_size());
127     std::advance(FuncArg, Ins[i].getOrigArgIndex());
128 
129     OriginalArgWasF128.push_back(
130         originalTypeIsF128(FuncArg->getType(), nullptr));
131     OriginalArgWasFloat.push_back(FuncArg->getType()->isFloatingPointTy());
132   }
133 }
134