Index: lib/Transforms/Utils/Evaluator.cpp =================================================================== --- lib/Transforms/Utils/Evaluator.cpp +++ lib/Transforms/Utils/Evaluator.cpp @@ -203,9 +203,16 @@ break; // Handle a constantexpr bitcast. case Instruction::BitCast: - if (auto *I = getInitializer(CE->getOperand(0))) + Constant *Val = getVal(CE->getOperand(0)); + Constant *Orig = nullptr; + auto MM = MutatedMemory.find(Val); + if (MM != MutatedMemory.end()) + Orig = MM->second; + else if (auto *I = getInitializer(CE->getOperand(0))) + Orig = I; + if (Orig) return ConstantFoldLoadThroughBitcast( - I, P->getType()->getPointerElementType(), DL); + Orig, P->getType()->getPointerElementType(), DL); break; } } Index: test/Transforms/GlobalOpt/static-const-bitcast.ll =================================================================== --- /dev/null +++ test/Transforms/GlobalOpt/static-const-bitcast.ll @@ -0,0 +1,62 @@ +; RUN: opt -globalopt %s -S -o - | FileCheck %s +target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" +target triple = "x86_64-unknown-linux-gnu" + +%struct.A = type { %class.Wrapper } +%class.Wrapper = type { i32 } + +$Wrapper = comdat any + +@kA = internal global %struct.A zeroinitializer, align 4 +; CHECK: @kA = internal unnamed_addr constant %struct.A { %class.Wrapper { i32 1036831949 } }, align 4 + +@llvm.global_ctors = appending global [1 x { i32, void ()*, i8* }] [{ i32, void ()*, i8* } { +i32 65535, void ()* @_GLOBAL__sub_I_const_static.cc, i8* null }] + +define dso_local i32 @AsBits(float* %x) #0 { +entry: + %0 = bitcast float* %x to i32* + %1 = load i32, i32* %0, align 4 + ret i32 %1 +} + +define internal void @__cxx_global_var_init() #1 section ".text.startup" { +entry: + call void @Wrapper(%class.Wrapper* getelementptr inbounds (%struct.A, %struct.A* @kA, i32 0, i32 0), float 0x3FB99999A0000000) + %0 = call {}* @llvm.invariant.start.p0i8(i64 4, i8* bitcast (%struct.A* @kA to i8*)) + ret void +} + +define linkonce_odr dso_local void @Wrapper(%class.Wrapper* %this, float %x) unnamed_addr #0 comdat align 2 { +entry: + %x.addr = alloca float, align 4 + store float %x, float* %x.addr, align 4 + %store_ = getelementptr inbounds %class.Wrapper, %class.Wrapper* %this, i32 0, i32 0 + %call = call i32 @AsBits(float* %x.addr) + store i32 %call, i32* %store_, align 4 + ret void +} + +declare {}* @llvm.invariant.start.p0i8(i64, i8* nocapture) #2 + +; Function Attrs: nounwind uwtable +define dso_local void @LoadIt(%struct.A* %c) #0 { +entry: + %0 = bitcast %struct.A* %c to i8* + call void @llvm.memcpy.p0i8.p0i8.i64(i8* align 4 %0, i8* align 4 bitcast (%struct.A* @kA to i8*), i64 4, i1 false) + ret void +} + +; Function Attrs: argmemonly nounwind +declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture writeonly, i8* nocapture readonly, i64, i1) #2 + +; Function Attrs: uwtable +define internal void @_GLOBAL__sub_I_const_static.cc() #1 section ".text.startup" { +entry: + call void @__cxx_global_var_init() + ret void +} + +attributes #0 = { nounwind uwtable "target-cpu"="x86-64" } +attributes #1 = { uwtable "target-cpu"="x86-64" } +attributes #2 = { argmemonly nounwind }