maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

[X86] Enable constexpr on BITSCAN intrinsics (PR31446) 

This enables constexpr BSF/BSR intrinsics defined in ia32intrin.h
This commit is contained in:
Simon Pilgrim 2020-08-21 11:37:40 +01:00
parent 9e6c09c0d9
commit 9ffc412e1a
3 changed files with 44 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
clang/docs/ReleaseNotes.rst
View File

@ -160,6 +160,12 @@ X86 Support in Clang
``_popcnt64``, ``__popcntd`` and ``__popcntq`` may now be used within
constexpr expressions.
- The x86 intrinsics ``_bit_scan_forward``, ``__bsfd`` and ``__bsfq`` may now
be used within constexpr expressions.
- The x86 intrinsics ``_bit_scan_reverse``, ``__bsrd`` and ``__bsrq`` may now
be used within constexpr expressions.
- The x86 intrinsics ``__bswap``, ``__bswapd``, ``__bswap64`` and ``__bswapq``
may now be used within constexpr expressions.

8
clang/lib/Headers/ia32intrin.h
View File

@ -36,7 +36,7 @@
* A 32-bit integer operand.
* \returns A 32-bit integer containing the bit number.
*/
static __inline__ int __DEFAULT_FN_ATTRS
static __inline__ int __DEFAULT_FN_ATTRS_CONSTEXPR
__bsfd(int __A) {
return __builtin_ctz(__A);
}
@ -53,7 +53,7 @@ __bsfd(int __A) {
* A 32-bit integer operand.
* \returns A 32-bit integer containing the bit number.
*/
static __inline__ int __DEFAULT_FN_ATTRS
static __inline__ int __DEFAULT_FN_ATTRS_CONSTEXPR
__bsrd(int __A) {
return 31 - __builtin_clz(__A);
}
@ -95,7 +95,7 @@ _bswap(int __A) {
* A 64-bit integer operand.
* \returns A 32-bit integer containing the bit number.
*/
static __inline__ int __DEFAULT_FN_ATTRS
static __inline__ int __DEFAULT_FN_ATTRS_CONSTEXPR
__bsfq(long long __A) {
return __builtin_ctzll(__A);
}
@ -112,7 +112,7 @@ __bsfq(long long __A) {
* A 64-bit integer operand.
* \returns A 32-bit integer containing the bit number.
*/
static __inline__ int __DEFAULT_FN_ATTRS
static __inline__ int __DEFAULT_FN_ATTRS_CONSTEXPR
__bsrq(long long __A) {
return 63 - __builtin_clzll(__A);
}

41
clang/test/CodeGen/bitscan-builtins.c
View File

@ -1,47 +1,74 @@
// RUN: %clang_cc1 -ffreestanding -triple x86_64-unknown-unknown -emit-llvm -o - %s | FileCheck %s
// RUN: %clang_cc1 -x c -ffreestanding %s -triple=x86_64-unknown-unknown -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK,CHECKC
// RUN: %clang_cc1 -x c++ -std=c++11 -ffreestanding %s -triple=x86_64-unknown-unknown -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK,CHECKCPP
// PR33722
// RUN: %clang_cc1 -ffreestanding -triple x86_64-unknown-unknown -fms-extensions -fms-compatibility-version=19.00 -emit-llvm -o - %s | FileCheck %s
// RUN: %clang_cc1 -x c -ffreestanding %s -triple x86_64-unknown-unknown -fms-extensions -fms-compatibility-version=19.00 -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK,CHECKC
// RUN: %clang_cc1 -x c++ -ffreestanding %s -triple x86_64-unknown-unknown -fms-extensions -fms-compatibility-version=19.00 -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK,CHECKCPP
#include <x86intrin.h>
int test_bit_scan_forward(int a) {
return _bit_scan_forward(a);
// CHECK: @test_bit_scan_forward
// CHECKC-LABEL: @test_bit_scan_forward
// CHECK: %[[call:.*]] = call i32 @llvm.cttz.i32(i32 %{{.*}}, i1 true)
// CHECK: ret i32 %[[call]]
}
int test_bit_scan_reverse(int a) {
return _bit_scan_reverse(a);
// CHECKC-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]]
}
int test__bsfd(int X) {
// CHECK: @test__bsfd
// CHECKC-LABEL: @test__bsfd
// CHECK: %[[call:.*]] = call i32 @llvm.cttz.i32(i32 %{{.*}}, i1 true)
return __bsfd(X);
}
int test__bsfq(long long X) {
// CHECK: @test__bsfq
// CHECKC-LABEL: @test__bsfq
// CHECK: %[[call:.*]] = call i64 @llvm.cttz.i64(i64 %{{.*}}, i1 true)
return __bsfq(X);
}
int test__bsrd(int X) {
// CHECK: @test__bsrd
// CHECKC-LABEL: @test__bsrd
// CHECK: %[[call:.*]] = call i32 @llvm.ctlz.i32(i32 %{{.*}}, i1 true)
// CHECK: %[[sub:.*]] = sub nsw i32 31, %[[call]]
return __bsrd(X);
}
int test__bsrq(long long X) {
// CHECK: @test__bsrq
// CHECKC-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 handling.
#if defined(__cplusplus) && (__cplusplus >= 201103L)
char bsf_0[_bit_scan_forward(0x00000001) == 0 ? 1 : -1];
char bsf_1[_bit_scan_forward(0x10000000) == 28 ? 1 : -1];
char bsr_0[_bit_scan_reverse(0x00000001) == 0 ? 1 : -1];
char bsr_1[_bit_scan_reverse(0x01000000) == 24 ? 1 : -1];
char bsfd_0[__bsfd(0x00000008) == 3 ? 1 : -1];
char bsfd_1[__bsfd(0x00010008) == 3 ? 1 : -1];
char bsrd_0[__bsrd(0x00000010) == 4 ? 1 : -1];
char bsrd_1[__bsrd(0x00100100) == 20 ? 1 : -1];
char bsfq_0[__bsfq(0x0000000800000000ULL) == 35 ? 1 : -1];
char bsfq_1[__bsfq(0x0004000000000000ULL) == 50 ? 1 : -1];
char bsrq_0[__bsrq(0x0000100800000000ULL) == 44 ? 1 : -1];
char bsrq_1[__bsrq(0x0004000100000000ULL) == 50 ? 1 : -1];
#endif