[clang] a82170f - [Headers] Add some intrinsic function descriptions to immintrin.h.

[Paul Robinson via cfe-commits]

Author: Paul Robinson
Date: 2023-04-04T06:26:05-07:00
New Revision: a82170fa41ca9756b0f67d0ed015adef325e8921

URL: https://github.com/llvm/llvm-project/commit/a82170fa41ca9756b0f67d0ed015adef325e8921
DIFF: https://github.com/llvm/llvm-project/commit/a82170fa41ca9756b0f67d0ed015adef325e8921.diff

LOG: [Headers] Add some intrinsic function descriptions to immintrin.h.

Differential Revision: https://reviews.llvm.org/D147461

Added: 
    

Modified: 
    clang/lib/Headers/immintrin.h

Removed: 
    


################################################################################
diff  --git a/clang/lib/Headers/immintrin.h b/clang/lib/Headers/immintrin.h
index 8e109af0f5817..d382ec88f30f7 100644
--- a/clang/lib/Headers/immintrin.h
+++ b/clang/lib/Headers/immintrin.h
@@ -284,18 +284,45 @@ _rdpid_u32(void) {
 
 #if !(defined(_MSC_VER) || defined(__SCE__)) || __has_feature(modules) ||      \
     defined(__RDRND__)
+/// Returns a 16-bit hardware-generated random value.
+///
+/// \headerfile <immintrin.h>
+///
+/// This intrinsic corresponds to the <c> RDRAND </c> instruction.
+///
+/// \param __p
+///    A pointer to a 16-bit memory location to place the random value.
+/// \returns 1 if the value was successfully generated, 0 otherwise.
 static __inline__ int __attribute__((__always_inline__, __nodebug__, __target__("rdrnd")))
 _rdrand16_step(unsigned short *__p)
 {
   return (int)__builtin_ia32_rdrand16_step(__p);
 }
 
+/// Returns a 32-bit hardware-generated random value.
+///
+/// \headerfile <immintrin.h>
+///
+/// This intrinsic corresponds to the <c> RDRAND </c> instruction.
+///
+/// \param __p
+///    A pointer to a 32-bit memory location to place the random value.
+/// \returns 1 if the value was successfully generated, 0 otherwise.
 static __inline__ int __attribute__((__always_inline__, __nodebug__, __target__("rdrnd")))
 _rdrand32_step(unsigned int *__p)
 {
   return (int)__builtin_ia32_rdrand32_step(__p);
 }
 
+/// Returns a 64-bit hardware-generated random value.
+///
+/// \headerfile <immintrin.h>
+///
+/// This intrinsic corresponds to the <c> RDRAND </c> instruction.
+///
+/// \param __p
+///    A pointer to a 64-bit memory location to place the random value.
+/// \returns 1 if the value was successfully generated, 0 otherwise.
 #ifdef __x86_64__
 static __inline__ int __attribute__((__always_inline__, __nodebug__, __target__("rdrnd")))
 _rdrand64_step(unsigned long long *__p)
@@ -325,48 +352,108 @@ _rdrand64_step(unsigned long long *__p)
 #if !(defined(_MSC_VER) || defined(__SCE__)) || __has_feature(modules) ||      \
     defined(__FSGSBASE__)
 #ifdef __x86_64__
+/// Reads the FS base register.
+///
+/// \headerfile <immintrin.h>
+///
+/// This intrinsic corresponds to the <c> RDFSBASE </c> instruction.
+///
+/// \returns The lower 32 bits of the FS base register.
 static __inline__ unsigned int __attribute__((__always_inline__, __nodebug__, __target__("fsgsbase")))
 _readfsbase_u32(void)
 {
   return __builtin_ia32_rdfsbase32();
 }
 
+/// Reads the FS base register.
+///
+/// \headerfile <immintrin.h>
+///
+/// This intrinsic corresponds to the <c> RDFSBASE </c> instruction.
+///
+/// \returns The contents of the FS base register.
 static __inline__ unsigned long long __attribute__((__always_inline__, __nodebug__, __target__("fsgsbase")))
 _readfsbase_u64(void)
 {
   return __builtin_ia32_rdfsbase64();
 }
 
+/// Reads the GS base register.
+///
+/// \headerfile <immintrin.h>
+///
+/// This intrinsic corresponds to the <c> RDGSBASE </c> instruction.
+///
+/// \returns The lower 32 bits of the GS base register.
 static __inline__ unsigned int __attribute__((__always_inline__, __nodebug__, __target__("fsgsbase")))
 _readgsbase_u32(void)
 {
   return __builtin_ia32_rdgsbase32();
 }
 
+/// Reads the GS base register.
+///
+/// \headerfile <immintrin.h>
+///
+/// This intrinsic corresponds to the <c> RDGSBASE </c> instruction.
+///
+/// \returns The contents of the GS base register.
 static __inline__ unsigned long long __attribute__((__always_inline__, __nodebug__, __target__("fsgsbase")))
 _readgsbase_u64(void)
 {
   return __builtin_ia32_rdgsbase64();
 }
 
+/// Modifies the FS base register.
+///
+/// \headerfile <immintrin.h>
+///
+/// This intrinsic corresponds to the <c> WRFSBASE </c> instruction.
+///
+/// \param __V
+///    Value to use for the lower 32 bits of the FS base register.
 static __inline__ void __attribute__((__always_inline__, __nodebug__, __target__("fsgsbase")))
 _writefsbase_u32(unsigned int __V)
 {
   __builtin_ia32_wrfsbase32(__V);
 }
 
+/// Modifies the FS base register.
+///
+/// \headerfile <immintrin.h>
+///
+/// This intrinsic corresponds to the <c> WRFSBASE </c> instruction.
+///
+/// \param __V
+///    Value to use for the FS base register.
 static __inline__ void __attribute__((__always_inline__, __nodebug__, __target__("fsgsbase")))
 _writefsbase_u64(unsigned long long __V)
 {
   __builtin_ia32_wrfsbase64(__V);
 }
 
+/// Modifies the GS base register.
+///
+/// \headerfile <immintrin.h>
+///
+/// This intrinsic corresponds to the <c> WRGSBASE </c> instruction.
+///
+/// \param __V
+///    Value to use for the lower 32 bits of the GS base register.
 static __inline__ void __attribute__((__always_inline__, __nodebug__, __target__("fsgsbase")))
 _writegsbase_u32(unsigned int __V)
 {
   __builtin_ia32_wrgsbase32(__V);
 }
 
+/// Modifies the GS base register.
+///
+/// \headerfile <immintrin.h>
+///
+/// This intrinsic corresponds to the <c> WRFSBASE </c> instruction.
+///
+/// \param __V
+///    Value to use for GS base register.
 static __inline__ void __attribute__((__always_inline__, __nodebug__, __target__("fsgsbase")))
 _writegsbase_u64(unsigned long long __V)
 {