| ; Test the static branch probability heuristics for no-return functions. |
| ; RUN: opt < %s -passes='print<branch-prob>' -disable-output 2>&1 | FileCheck %s |
| |
| declare void @abort() noreturn |
| |
| define i32 @test1(i32 %a, i32 %b) { |
| ; CHECK: Printing analysis {{.*}} for function 'test1' |
| entry: |
| %cond = icmp eq i32 %a, 42 |
| br i1 %cond, label %exit, label %abort |
| ; CHECK: edge entry -> exit probability is 0x7ffff800 / 0x80000000 = 100.00% [HOT edge] |
| ; CHECK: edge entry -> abort probability is 0x00000800 / 0x80000000 = 0.00% |
| |
| abort: |
| call void @abort() noreturn |
| unreachable |
| |
| exit: |
| ret i32 %b |
| } |
| |
| define i32 @test2(i32 %a, i32 %b) { |
| ; CHECK: Printing analysis {{.*}} for function 'test2' |
| entry: |
| switch i32 %a, label %exit [i32 1, label %case_a |
| i32 2, label %case_b |
| i32 3, label %case_c |
| i32 4, label %case_d] |
| ; CHECK: edge entry -> exit probability is 0x7fffe000 / 0x80000000 = 100.00% [HOT edge] |
| ; CHECK: edge entry -> case_a probability is 0x00000800 / 0x80000000 = 0.00% |
| ; CHECK: edge entry -> case_b probability is 0x00000800 / 0x80000000 = 0.00% |
| ; CHECK: edge entry -> case_c probability is 0x00000800 / 0x80000000 = 0.00% |
| ; CHECK: edge entry -> case_d probability is 0x00000800 / 0x80000000 = 0.00% |
| |
| case_a: |
| br label %case_b |
| |
| case_b: |
| br label %case_c |
| |
| case_c: |
| br label %case_d |
| |
| case_d: |
| call void @abort() noreturn |
| unreachable |
| |
| exit: |
| ret i32 %b |
| } |
| |
| define i32 @test3(i32 %a, i32 %b) { |
| ; CHECK: Printing analysis {{.*}} for function 'test3' |
| ; Make sure we unify across multiple conditional branches. |
| entry: |
| %cond1 = icmp eq i32 %a, 42 |
| br i1 %cond1, label %exit, label %dom |
| ; CHECK: edge entry -> exit probability is 0x7ffff800 / 0x80000000 = 100.00% [HOT edge] |
| ; CHECK: edge entry -> dom probability is 0x00000800 / 0x80000000 = 0.00% |
| |
| dom: |
| %cond2 = icmp ult i32 %a, 42 |
| br i1 %cond2, label %idom1, label %idom2 |
| ; CHECK: edge dom -> idom1 probability is 0x40000000 / 0x80000000 = 50.00% |
| ; CHECK: edge dom -> idom2 probability is 0x40000000 / 0x80000000 = 50.00% |
| |
| idom1: |
| br label %abort |
| |
| idom2: |
| br label %abort |
| |
| abort: |
| call void @abort() noreturn |
| unreachable |
| |
| exit: |
| ret i32 %b |
| } |
| |
| define i32 @test4(i32 %a, i32 %b) { |
| ; CHECK: Printing analysis {{.*}} for function 'test4' |
| ; Make sure we handle loops post-dominated by unreachables. |
| entry: |
| %cond1 = icmp eq i32 %a, 42 |
| br i1 %cond1, label %header, label %exit |
| ; CHECK: edge entry -> header probability is 0x00000800 / 0x80000000 = 0.00% |
| ; CHECK: edge entry -> exit probability is 0x7ffff800 / 0x80000000 = 100.00% [HOT edge] |
| |
| header: |
| br label %body |
| |
| body: |
| %cond2 = icmp eq i32 %a, 42 |
| br i1 %cond2, label %header, label %abort |
| ; CHECK: edge body -> header probability is 0x7ffff800 / 0x80000000 = 100.00% [HOT edge] |
| ; CHECK: edge body -> abort probability is 0x00000800 / 0x80000000 = 0.00% |
| abort: |
| call void @abort() noreturn |
| unreachable |
| |
| 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 0x40000000 / 0x80000000 = 50.00% |
| ; CHECK: edge if.then -> lpad probability is 0x40000000 / 0x80000000 = 50.00% |
| |
| 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*) |