test/CodeGen/X86/bitscan-builtins.c

// RUN: %clang_cc1 -x c -ffreestanding %s -triple=x86_64-unknown-unknown -no-enable-noundef-analysis -emit-llvm -o - | FileCheck %s
// RUN: %clang_cc1 -x c++ -std=c++11 -ffreestanding %s -triple=x86_64-unknown-unknown -no-enable-noundef-analysis -emit-llvm -o - | FileCheck %s

// RUN: %clang_cc1 -x c -ffreestanding %s -triple=x86_64-unknown-unknown -no-enable-noundef-analysis -emit-llvm -o - -fexperimental-new-constant-interpreter | FileCheck %s
// RUN: %clang_cc1 -x c++ -std=c++11 -ffreestanding %s -triple=x86_64-unknown-unknown -no-enable-noundef-analysis -emit-llvm -o - -fexperimental-new-constant-interpreter | FileCheck %s

// PR33722
// RUN: %clang_cc1 -x c -ffreestanding %s -triple x86_64-unknown-unknown -fms-extensions -fms-compatibility-version=19.00 -no-enable-noundef-analysis -emit-llvm -o - | FileCheck %s
// RUN: %clang_cc1 -x c++ -ffreestanding %s -triple x86_64-unknown-unknown -fms-extensions -fms-compatibility-version=19.00 -no-enable-noundef-analysis -emit-llvm -o - | FileCheck %s


#include <x86intrin.h>
#include "builtin_test_helpers.h"

int test_bit_scan_forward(int a) {
// CHECK-LABEL: test_bit_scan_forward
// CHECK: %[[call:.*]] = call i32 @llvm.cttz.i32(i32 %{{.*}}, i1 true)
// CHECK: ret i32 %[[call]]
  return _bit_scan_forward(a);
}
TEST_CONSTEXPR(_bit_scan_forward(0x00000001) ==  0);
TEST_CONSTEXPR(_bit_scan_forward(0x10000000) == 28);

int test_bit_scan_reverse(int a) {
// CHECK-LABEL: test_bit_scan_reverse
// CHECK:  %[[call:.*]] = call i32 @llvm.ctlz.i32(i32 %{{.*}}, i1 true)
// CHECK:  %[[sub:.*]] = sub nsw i32 31, %[[call]]
// CHECK: ret i32 %[[sub]]
  return _bit_scan_reverse(a);
}
TEST_CONSTEXPR(_bit_scan_reverse(0x00000001) ==  0);
TEST_CONSTEXPR(_bit_scan_reverse(0x01000000) == 24);

int test__bsfd(int X) {
// CHECK-LABEL: test__bsfd
// CHECK: %[[call:.*]] = call i32 @llvm.cttz.i32(i32 %{{.*}}, i1 true)
  return __bsfd(X);
}
TEST_CONSTEXPR(__bsfd(0x00000008) ==  3);
TEST_CONSTEXPR(__bsfd(0x00010008) ==  3);

int test__bsfq(long long X) {
// CHECK-LABEL: test__bsfq
// CHECK: %[[call:.*]] = call i64 @llvm.cttz.i64(i64 %{{.*}}, i1 true)
  return __bsfq(X);
}
TEST_CONSTEXPR(__bsfq(0x0000000800000000ULL) == 35);
TEST_CONSTEXPR(__bsfq(0x0004000000000000ULL) == 50);

int test__bsrd(int X) {
// CHECK-LABEL: test__bsrd
// CHECK:  %[[call:.*]] = call i32 @llvm.ctlz.i32(i32 %{{.*}}, i1 true)
// CHECK:  %[[sub:.*]] = sub nsw i32 31, %[[call]]
  return __bsrd(X);
}
TEST_CONSTEXPR(__bsrd(0x00000010) ==  4);
TEST_CONSTEXPR(__bsrd(0x00100100) == 20);

int test__bsrq(long long X) {
// CHECK-LABEL: test__bsrq
// CHECK:  %[[call:.*]] = call i64 @llvm.ctlz.i64(i64 %{{.*}}, i1 true)
// CHECK:  %[[cast:.*]] = trunc i64 %[[call]] to i32
// CHECK:  %[[sub:.*]] = sub nsw i32 63, %[[cast]]
  return __bsrq(X);
}
TEST_CONSTEXPR(__bsrq(0x0000100800000000ULL) == 44);
TEST_CONSTEXPR(__bsrq(0x0004000100000000ULL) == 50);