Index: lib/Transforms/InstCombine/InstructionCombining.cpp =================================================================== --- lib/Transforms/InstCombine/InstructionCombining.cpp +++ lib/Transforms/InstCombine/InstructionCombining.cpp @@ -3160,7 +3160,7 @@ // Lower dbg.declare intrinsics otherwise their value may be clobbered // by instcombiner. - bool DbgDeclaresChanged = LowerDbgDeclare(F); + bool MadeIRChange = LowerDbgDeclare(F); // Iterate while there is work to do. int Iteration = 0; @@ -3169,18 +3169,17 @@ DEBUG(dbgs() << "\n\nINSTCOMBINE ITERATION #" << Iteration << " on " << F.getName() << "\n"); - bool Changed = prepareICWorklistFromFunction(F, DL, &TLI, Worklist); + MadeIRChange |= prepareICWorklistFromFunction(F, DL, &TLI, Worklist); InstCombiner IC(Worklist, &Builder, F.optForMinSize(), ExpensiveCombines, AA, AC, TLI, DT, DL, LI); IC.MaxArraySizeForCombine = MaxArraySize; - Changed |= IC.run(); - if (!Changed) + if (!IC.run()) break; } - return DbgDeclaresChanged || Iteration > 1; + return MadeIRChange || Iteration > 1; } PreservedAnalyses InstCombinePass::run(Function &F, Index: test/Transforms/InstCombine/constant-fold-iteration.ll =================================================================== --- /dev/null +++ test/Transforms/InstCombine/constant-fold-iteration.ll @@ -0,0 +1,10 @@ +; RUN: opt < %s -instcombine -S -debug 2>&1 | FileCheck %s +; REQUIRES: asserts +target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:32:32-n8:16:32" + +define i32 @a() nounwind readnone { +entry: + ret i32 zext (i1 icmp eq (i32 0, i32 ptrtoint (i32 ()* @a to i32)) to i32) +} +; CHECK: INSTCOMBINE ITERATION #1 +; CHECK-NOT: INSTCOMBINE ITERATION #2