1 // RUN: %clang_cc1 -triple x86_64-unknown-unknown -emit-llvm -o - %s -O1 -disable-llvm-optzns | FileCheck %s --check-prefix=ALL --check-prefix=O1 2 // RUN: %clang_cc1 -triple x86_64-unknown-unknown -emit-llvm -o - %s -O0 | FileCheck %s --check-prefix=ALL --check-prefix=O0 3 4 // In all tests, make sure that no expect is generated if optimizations are off. 5 // If optimizations are on, generate the correct expect and preserve other necessary operations. 6 7 int expect_taken(int x) { 8 // ALL-LABEL: define i32 @expect_taken 9 // O1: call i64 @llvm.expect.i64(i64 {{%.*}}, i64 1) 10 // O0-NOT: @llvm.expect 11 12 if (__builtin_expect (x, 1)) 13 return 0; 14 return x; 15 } 16 17 18 int expect_not_taken(int x) { 19 // ALL-LABEL: define i32 @expect_not_taken 20 // O1: call i64 @llvm.expect.i64(i64 {{%.*}}, i64 0) 21 // O0-NOT: @llvm.expect 22 23 if (__builtin_expect (x, 0)) 24 return 0; 25 return x; 26 } 27 28 29 int x; 30 int y(void); 31 void foo(); 32 33 void expect_value_side_effects() { 34 // ALL-LABEL: define void @expect_value_side_effects() 35 // ALL: [[CALL:%.*]] = call i32 @y 36 // O1: [[SEXT:%.*]] = sext i32 [[CALL]] to i64 37 // O1: call i64 @llvm.expect.i64(i64 {{%.*}}, i64 [[SEXT]]) 38 // O0-NOT: @llvm.expect 39 40 if (__builtin_expect (x, y())) 41 foo (); 42 } 43 44 45 // Make sure that issigprocmask() is called before bar()? 46 // There's no compare, so there's nothing to expect? 47 // rdar://9330105 48 void isigprocmask(void); 49 long bar(); 50 51 int main() { 52 // ALL-LABEL: define i32 @main() 53 // ALL: call void @isigprocmask() 54 // ALL: [[CALL:%.*]] = call i64 (...) @bar() 55 // O1: call i64 @llvm.expect.i64(i64 0, i64 [[CALL]]) 56 // O0-NOT: @llvm.expect 57 58 (void) __builtin_expect((isigprocmask(), 0), bar()); 59 } 60 61 62 int switch_cond(int x) { 63 // ALL-LABEL: define i32 @switch_cond 64 // O1: call i64 @llvm.expect.i64(i64 {{%.*}}, i64 5) 65 // O0-NOT: @llvm.expect 66 67 switch(__builtin_expect(x, 5)) { 68 default: 69 return 0; 70 case 0: 71 case 1: 72 case 2: 73 return 1; 74 case 5: 75 return 5; 76 }; 77 78 return 0; 79 } 80 81
