Fix the build for clang 3.8 and MINIMAL=1.

src/IceTargetLoweringARM32.cpp

 //===- subzero/src/IceTargetLoweringARM32.cpp - ARM32 lowering ------------===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 38 matching lines @@
 
 const struct TableIcmp32_ {
   CondARM32::Cond Mapping;
 } TableIcmp32[] = {
 #define X(val, is_signed, swapped64, C_32, C1_64, C2_64)                       \
   { CondARM32::C_32 }                                                          \
   ,
     ICMPARM32_TABLE
 #undef X
 };
-const size_t TableIcmp32Size = llvm::array_lengthof(TableIcmp32);

[Jim Stichnoth, 2015/09/09 18:52:00]

I assume the problem was an unused variable in NODEBUG mode?

Would constexpr have fixed it?

[ascull, 2015/09/09 18:55:06]

I gave it a go but it still complained it was unused.

 
 // The following table summarizes the logic for lowering the icmp instruction
 // for the i64 type. Two conditional moves are needed for setting to 1 or 0.
 // The operands may need to be swapped, and there is a slight difference
 // for signed vs unsigned (comparing hi vs lo first, and using cmp vs sbc).
 const struct TableIcmp64_ {
   bool IsSigned;
   bool Swapped;
   CondARM32::Cond C1, C2;
 } TableIcmp64[] = {
 #define X(val, is_signed, swapped64, C_32, C1_64, C2_64)                       \
   { is_signed, swapped64, CondARM32::C1_64, CondARM32::C2_64 }                 \
   ,
     ICMPARM32_TABLE
 #undef X
 };
-const size_t TableIcmp64Size = llvm::array_lengthof(TableIcmp64);
 
 CondARM32::Cond getIcmp32Mapping(InstIcmp::ICond Cond) {
   size_t Index = static_cast<size_t>(Cond);
-  assert(Index < TableIcmp32Size);
+  assert(Index < llvm::array_lengthof(TableIcmp32));
   return TableIcmp32[Index].Mapping;
 }
 
 // In some cases, there are x-macros tables for both high-level and
 // low-level instructions/operands that use the same enum key value.
 // The tables are kept separate to maintain a proper separation
 // between abstraction layers.  There is a risk that the tables could
 // get out of sync if enum values are reordered or if entries are
 // added or deleted.  The following dummy namespaces use
 // static_asserts to ensure everything is kept in sync.
@@ skipping 2067 matching lines @@
   // and one conditonal reg mov. That has few dependencies for good ILP,
   // but is a longer sequence.
   //
   // So, we are going with the GCC version since it's usually better (except
   // perhaps for eq/ne). We could revisit special-casing eq/ne later.
   Constant *Zero = Ctx->getConstantZero(IceType_i32);
   Constant *One = Ctx->getConstantInt32(1);
   if (Src0->getType() == IceType_i64) {
     InstIcmp::ICond Conditon = Inst->getCondition();
     size_t Index = static_cast<size_t>(Conditon);
-    assert(Index < TableIcmp64Size);
+    assert(Index < llvm::array_lengthof(TableIcmp64));
     Variable *Src0Lo, *Src0Hi;
     Operand *Src1LoRF, *Src1HiRF;
     if (TableIcmp64[Index].Swapped) {
       Src0Lo = legalizeToReg(loOperand(Src1));
       Src0Hi = legalizeToReg(hiOperand(Src1));
       Src1LoRF = legalize(loOperand(Src0), Legal_Reg | Legal_Flex);
       Src1HiRF = legalize(hiOperand(Src0), Legal_Reg | Legal_Flex);
     } else {
       Src0Lo = legalizeToReg(loOperand(Src0));
       Src0Hi = legalizeToReg(hiOperand(Src0));
@@ skipping 877 matching lines @@
       << ".eabi_attribute 68, 1   @ Tag_Virtualization_use\n";
   if (CPUFeatures.hasFeature(TargetARM32Features::HWDivArm)) {
     Str << ".eabi_attribute 44, 2   @ Tag_DIV_use\n";
   }
   // Technically R9 is used for TLS with Sandboxing, and we reserve it.
   // However, for compatibility with current NaCl LLVM, don't claim that.
   Str << ".eabi_attribute 14, 3   @ Tag_ABI_PCS_R9_use: Not used\n";
 }
 
 } // end of namespace Ice