Index: llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp =================================================================== --- llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp +++ llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp @@ -3012,6 +3012,7 @@ ++NumDeadInst; DEBUG(dbgs() << "IC: DCE: " << *Inst << '\n'); Inst->eraseFromParent(); + MadeIRChange = true; continue; } @@ -3025,6 +3026,7 @@ ++NumConstProp; if (isInstructionTriviallyDead(Inst, TLI)) Inst->eraseFromParent(); + MadeIRChange = true; continue; } Index: llvm/trunk/test/Transforms/InstCombine/early_constfold_changes_IR.ll =================================================================== --- llvm/trunk/test/Transforms/InstCombine/early_constfold_changes_IR.ll +++ llvm/trunk/test/Transforms/InstCombine/early_constfold_changes_IR.ll @@ -0,0 +1,20 @@ +; This run line verifies that we get the expected constant fold. +; RUN: opt < %s -instcombine -S | FileCheck %s + +; This run line verifies that InstructionCombiningPass::runOnFunction reports +; this as a modification of the IR. +; RUN: opt < %s -instcombine -disable-output -debug-pass=Details 2>&1 | FileCheck %s --check-prefix=DETAILS + +define i32 @foo(i32 %arg) #0 { +; CHECK-LABEL: @foo( +; CHECK-NEXT: entry: +; CHECK-NEXT: [[AND:%.*]] = and i32 [[ARG:%.*]], 7 +; CHECK-NEXT: ret i32 [[AND]] +; +entry: + %or = or i32 0, 7 + %and = and i32 %arg, %or + ret i32 %and +} + +; DETAILS: Made Modification 'Combine redundant instructions' on Function 'foo' Index: llvm/trunk/test/Transforms/InstCombine/early_dce_clobbers_callgraph.ll =================================================================== --- llvm/trunk/test/Transforms/InstCombine/early_dce_clobbers_callgraph.ll +++ llvm/trunk/test/Transforms/InstCombine/early_dce_clobbers_callgraph.ll @@ -0,0 +1,31 @@ +; RUN: opt < %s -inline -instcombine -S | FileCheck %s + +; This test case exposed a bug in instcombine where the early +; DCE of a call wasn't recognized as changing the IR. +; So when runOnFunction propagated the "made changes" upwards +; to the CallGraphSCCPass it signalled that no changes had been +; made, so CallGraphSCCPass assumed that the old CallGraph, +; as known by that pass manager, still was up-to-date. +; +; This was detected as an assert when trying to remove the +; no longer used function 'bar' (due to incorrect reference +; count in the CallGraph). + +attributes #0 = { noinline norecurse nounwind readnone } + +define void @foo() #0 { +; CHECK-LABEL: @foo( +; CHECK-NEXT: entry: +; CHECK-NEXT: ret void +; +entry: + %call = call i32 @bar() + ret void +} + +define internal i32 @bar() #0 { +; CHECK-NOT: bar +entry: + ret i32 42 +} +