// Test that big branch weights get scaled down to 32-bits, rather than just // truncated. // RUN: llvm-profdata merge %S/Inputs/c-counter-overflows.proftext -o %t.profdata // RUN: %clang_cc1 -triple x86_64-apple-macosx10.9 -main-file-name c-counter-overflows.c %s -o - -emit-llvm -fprofile-instr-use=%t.profdata | FileCheck %s typedef unsigned long long uint64_t; int main(int argc, const char *argv[]) { // Need counts higher than 32-bits. // CHECK: br {{.*}} !prof ![[FOR:[0-9]+]] // max = 0xffffffff0 // scale = 0xffffffff0 / 0xffffffff + 1 = 17 // loop-body: 0xffffffff0 / 17 + 1 = 0xf0f0f0f0 + 1 = 4042322161 => -252645135 // loop-exit: 0x000000001 / 17 + 1 = 0x00000000 + 1 = 1 => 1 for (uint64_t I = 0; I < 0xffffffff0; ++I) { // max = 0xffffffff * 15 = 0xefffffff1 // scale = 0xefffffff1 / 0xffffffff + 1 = 16 // CHECK: br {{.*}} !prof ![[IF:[0-9]+]] if (I & 0xf) { // 0xefffffff1 / 16 + 1 = 0xefffffff + 1 = 4026531840 => -268435456 } else { // 0x0ffffffff / 16 + 1 = 0x0fffffff + 1 = 268435456 => 268435456 } // max = 0xffffffff * 5 = 0x4fffffffb // scale = 0x4fffffffb / 0xffffffff + 1 = 6 // CHECK: ], !prof ![[SWITCH:[0-9]+]] switch ((I & 0xf) / 5) { case 0: // 0x4fffffffb / 6 = 0xd5555554 + 1 = 3579139413 => -715827883 break; case 1: // 0x4fffffffb / 6 = 0xd5555554 + 1 = 3579139413 => -715827883 break; case 2: // 0x4fffffffb / 6 = 0xd5555554 + 1 = 3579139413 => -715827883 break; default: // 0x0ffffffff / 6 = 0x2aaaaaaa + 1 = 715827883 => 715827883 break; } } return 0; } // CHECK-DAG: ![[FOR]] = !{!"branch_weights", i32 -252645135, i32 1} // CHECK-DAG: ![[IF]] = !{!"branch_weights", i32 -268435456, i32 268435456} // CHECK-DAG: ![[SWITCH]] = !{!"branch_weights", i32 715827883, i32 -715827883, i32 -715827883, i32 -715827883}