[clang] 286cefc - [clang][X86] Add __cpuidex function to cpuid.h

[Aiden Grossman via cfe-commits]

Author: Aiden Grossman
Date: 2023-05-17T19:38:28Z
New Revision: 286cefcf35d0f55c57184c4219b95e82c96f1420

URL: https://github.com/llvm/llvm-project/commit/286cefcf35d0f55c57184c4219b95e82c96f1420
DIFF: https://github.com/llvm/llvm-project/commit/286cefcf35d0f55c57184c4219b95e82c96f1420.diff

LOG: [clang][X86] Add __cpuidex function to cpuid.h

MSVC has a `__cpuidex` function implemented to call the underlying cpuid
instruction which accepts a leaf, subleaf, and data array that the output
data is written into. This patch adds this functionality into clang
under the cpuid.h header. This also makes clang match GCC's behavior.
GCC has had `__cpuidex` in its cpuid.h since 2020.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D150646

Added: 
    

Modified: 
    clang/lib/Headers/cpuid.h
    clang/test/Headers/cpuid.c

Removed: 
    


################################################################################
diff  --git a/clang/lib/Headers/cpuid.h b/clang/lib/Headers/cpuid.h
index 1ad6853a97c9d..22260c48c0c42 100644
--- a/clang/lib/Headers/cpuid.h
+++ b/clang/lib/Headers/cpuid.h
@@ -328,4 +328,10 @@ static __inline int __get_cpuid_count (unsigned int __leaf,
     return 1;
 }
 
+static __inline void __cpuidex (int __cpu_info[4], int __leaf, int __subleaf)
+{
+  __cpuid_count(__leaf, __subleaf, __cpu_info[0], __cpu_info[1], __cpu_info[2],
+                __cpu_info[3]);
+}
+
 #endif /* __CPUID_H */

diff  --git a/clang/test/Headers/cpuid.c b/clang/test/Headers/cpuid.c
index 7e485495c1066..6ed12eca7a61d 100644
--- a/clang/test/Headers/cpuid.c
+++ b/clang/test/Headers/cpuid.c
@@ -6,14 +6,19 @@
 
 // CHECK-64: {{.*}} call { i32, i32, i32, i32 } asm "  xchgq  %rbx,${1:q}\0A cpuid\0A xchgq %rbx,${1:q}", "={ax},=r,={cx},={dx},0,~{dirflag},~{fpsr},~{flags}"(i32 %{{[a-z0-9]+}})
 // CHECK-64: {{.*}} call { i32, i32, i32, i32 } asm "  xchgq  %rbx,${1:q}\0A  cpuid\0A  xchgq  %rbx,${1:q}", "={ax},=r,={cx},={dx},0,2,~{dirflag},~{fpsr},~{flags}"(i32 %{{[a-z0-9]+}}, i32 %{{[a-z0-9]+}})
+// CHECK-64: {{.*}} call { i32, i32, i32, i32 } asm "  xchgq  %rbx,${1:q}\0A  cpuid\0A  xchgq  %rbx,${1:q}", "={ax},=r,={cx},={dx},0,2,~{dirflag},~{fpsr},~{flags}"(i32 %{{[a-z0-9]+}}, i32 %{{[a-z0-9]+}})
 
 // CHECK-32: {{.*}} call { i32, i32, i32, i32 } asm "cpuid", "={ax},={bx},={cx},={dx},0,~{dirflag},~{fpsr},~{flags}"(i32 %{{[a-z0-9]+}})
 // CHECK-32: {{.*}} call { i32, i32, i32, i32 } asm "cpuid", "={ax},={bx},={cx},={dx},0,2,~{dirflag},~{fpsr},~{flags}"(i32 %{{[a-z0-9]+}}, i32 %{{[a-z0-9]+}})
+// CHECK-32: {{.*}} call { i32, i32, i32, i32 } asm "cpuid", "={ax},={bx},={cx},={dx},0,2,~{dirflag},~{fpsr},~{flags}"(i32 %{{[a-z0-9]+}}, i32 %{{[a-z0-9]+}})
 
 unsigned eax0, ebx0, ecx0, edx0;
 unsigned eax1, ebx1, ecx1, edx1;
 
+int cpuid_info[4];
+
 void test_cpuid(unsigned level, unsigned count) {
   __cpuid(level, eax1, ebx1, ecx1, edx1);
   __cpuid_count(level, count, eax0, ebx0, ecx0, edx0);
+  __cpuidex(cpuid_info, level, count);
 }