Index: lib/Analysis/BranchProbabilityInfo.cpp =================================================================== --- lib/Analysis/BranchProbabilityInfo.cpp +++ lib/Analysis/BranchProbabilityInfo.cpp @@ -147,6 +147,16 @@ if (TI->getNumSuccessors() == 1 || UnreachableEdges.empty()) return false; + // If the terminator is an InvokeInst, check only the normal destination block + // as the unwind edge of InvokeInst is also very unlikely taken. + if (auto *II = dyn_cast(TI)) + if (PostDominatedByUnreachable.count(II->getNormalDest())) { + PostDominatedByUnreachable.insert(BB); + // Return false here so that edge weights for InvokeInst could be decided + // in calcInvokeHeuristics(). + return false; + } + uint32_t UnreachableWeight = std::max(UR_TAKEN_WEIGHT / (unsigned)UnreachableEdges.size(), MIN_WEIGHT); for (SmallVectorImpl::iterator I = UnreachableEdges.begin(), Index: test/Analysis/BranchProbabilityInfo/noreturn.ll =================================================================== --- test/Analysis/BranchProbabilityInfo/noreturn.ll +++ test/Analysis/BranchProbabilityInfo/noreturn.ll @@ -77,3 +77,48 @@ exit: ret i32 %b } + +@_ZTIi = external global i8* + +; CHECK-LABEL: throwSmallException +; CHECK-NOT: invoke i32 @smallFunction +define i32 @throwSmallException(i32 %idx, i32 %limit) #0 personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) { +entry: + %cmp = icmp sge i32 %idx, %limit + br i1 %cmp, label %if.then, label %if.end +; CHECK: edge entry -> if.then probability is 0x00000800 / 0x80000000 = 0.00% +; CHECK: edge entry -> if.end probability is 0x7ffff800 / 0x80000000 = 100.00% [HOT edge] + +if.then: ; preds = %entry + %exception = call i8* @__cxa_allocate_exception(i64 1) #0 + invoke i32 @smallFunction(i32 %idx) + to label %invoke.cont unwind label %lpad +; CHECK: edge if.then -> invoke.cont probability is 0x7ffff800 / 0x80000000 = 100.00% [HOT edge] +; CHECK: edge if.then -> lpad probability is 0x00000800 / 0x80000000 = 0.00% + +invoke.cont: ; preds = %if.then + call void @__cxa_throw(i8* %exception, i8* bitcast (i8** @_ZTIi to i8*), i8* null) #1 + unreachable + +lpad: ; preds = %if.then + %ll = landingpad { i8*, i32 } + cleanup + ret i32 %idx + +if.end: ; preds = %entry + ret i32 %idx +} + +@a = global i32 4 +define i32 @smallFunction(i32 %a) { +entry: + %r = load volatile i32, i32* @a + ret i32 %r +} + +attributes #0 = { nounwind } +attributes #1 = { noreturn } + +declare i8* @__cxa_allocate_exception(i64) +declare i32 @__gxx_personality_v0(...) +declare void @__cxa_throw(i8*, i8*, i8*) Index: test/CodeGen/X86/catchret-empty-fallthrough.ll =================================================================== --- test/CodeGen/X86/catchret-empty-fallthrough.ll +++ test/CodeGen/X86/catchret-empty-fallthrough.ll @@ -34,12 +34,14 @@ ; CHECK-LABEL: foo: # @foo ; CHECK: testb $1, %cl -; CHECK: jne .LBB0_[[return:[0-9]+]] +; CHECK: je .LBB0_[[try:[0-9]+]] +; CHECK: .LBB0_[[return:[0-9]+]]: +; CHECK: retq +; CHECK: .LBB0_[[try]]: ; CHECK: .Ltmp0: ; CHECK: callq bar ; CHECK: .Ltmp1: ; CHECK: .LBB0_[[catch:[0-9]+]]: -; CHECK: .LBB0_[[return]]: ; CHECK: .seh_handlerdata ; CHECK-NEXT: .long (.Llsda_end0-.Llsda_begin0)/16