Commit Graph

11 Commits

Author SHA1 Message Date
Craig Topper 1f2b181689 [Builltins][X86] Provide implementations of __lzcnt16, __lzcnt, __lzcnt64 for MS compatibility. Remove declarations from intrin.h and implementations from lzcntintrin.h
intrin.h had forward declarations for these and lzcntintrin.h had implementations that were only available with -mlzcnt or a -march that supported the lzcnt feature.

For MS compatibility we should always have these builtins available regardless of X86 being the target or the CPU support the lzcnt instruction. The backends should be able to gracefully fallback to something support even if its just shifts and bit ops.

Unfortunately, gcc also implements 2 of the 3 function names here on X86 when lzcnt feature is enabled.

This patch adds builtins for these for MSVC compatibility and drops the forward declarations from intrin.h. To keep the gcc compatibility the two intrinsics that collided have been turned into macros that use the X86 specific builtins with the lzcnt feature check. These macros are only defined when _MSC_VER is not defined. Without them being macros we can get a redefinition error because -ms-extensions doesn't seem to set _MSC_VER but does make the MS builtins available.

Should fix PR40014

Differential Revision: https://reviews.llvm.org/D55677

llvm-svn: 349098
2018-12-14 00:21:02 +00:00
Craig Topper fb5d9f2849 [X86] For lzcnt/tzcnt intrinsics use cttz/ctlz intrinsics with zero_undef flag set to false.
Previously we used a select and the zero_undef=true intrinsic. In -O2 this pattern will get optimized to zero_undef=false. But in -O0 this optimization won't happen. This results in a compare and cmov being wrapped around a tzcnt/lzcnt instruction.

By using the zero_undef=false intrinsic directly without the select, we can improve the -O0 codegen to just an lzcnt/tzcnt instruction.

Differential Revision: https://reviews.llvm.org/D52392

llvm-svn: 343126
2018-09-26 17:01:44 +00:00
Ekaterina Romanova 9b412153bf [DOXYGEN] Formatting changes for better intrinsics documentation rendering
(1) I added some \see cross-references to a few select intrinsics that are related (and have the same or similar semantics). 

(2) pmmintrin.h, smmintrin.h, xmmintrin.h have very few minor formatting changes. They make rendering of our intrinsics documentation better. 

llvm-svn: 333065
2018-05-23 06:33:22 +00:00
Adrian Prantl 9fc8faf9e6 Remove \brief commands from doxygen comments.
This is similar to the LLVM change https://reviews.llvm.org/D46290.

We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.

Patch produced by

for i in $(git grep -l '\@brief'); do perl -pi -e 's/\@brief //g' $i & done
for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done

Differential Revision: https://reviews.llvm.org/D46320

llvm-svn: 331834
2018-05-09 01:00:01 +00:00
Ekaterina Romanova 06b1914cb7 Add doxygen comments for lzcntintrin.h's intrinsics.
The doxygen comments are automatically generated based on Sony's intrinsics document.

I got an OK from Eric Christopher to commit doxygen comments without prior code
review upstream. This patch was internally reviewed by Charles Li.

llvm-svn: 287317
2016-11-18 06:26:01 +00:00
Michael Kuperstein e45af54cdb [X86] Rename DEFAULT_FN_ATTR macro to __DEFAULT_FN_ATTR
llvm-svn: 241065
2015-06-30 13:36:19 +00:00
Eric Christopher 9fc7fb274e Update the intel intrinsic headers to use the target attribute support.
This involved removing the conditional inclusion and replacing them
with target attributes matching the original conditional inclusion
and checks. The testcase update removes the macro checks for each
file and replaces them with usage of the __target__ attribute, e.g.:

int __attribute__((__target__(("sse3")))) foo(int a) {
  _mm_mwait(0, 0);
  return 4;
}

This usage does require the enclosing function have the requisite
__target__ attribute for inlining and code generation - also for
any macro intrinsic uses in the enclosing function. There's no change
for existing uses of the intrinsic headers.

llvm-svn: 239883
2015-06-17 07:09:32 +00:00
Eric Christopher 4d185168e9 Use a define for per-file function attributes for the Intel intrinsic headers.
This is a precursor to changing them to use the new target attribute
code.

llvm-svn: 239882
2015-06-17 07:09:20 +00:00
Craig Topper e1c664b136 Add _lzcnt_u32 and _lzcnt_u64 to lzcntintrin.h to match Intel documentation names for these intrinsics.
llvm-svn: 221066
2014-11-01 22:50:57 +00:00
Craig Topper 3ca55d9c41 Avoid undefined behavior in the x86 lzcnt header file by explicitly checking for 0 before calling __builtin_clz. Without this the optimizers may take advantage of the undefined behavior and produce incorrect results. LLVM itself still needs to be taught to merge the zero check into the llvm.ctlz with defined zero behavior.
llvm-svn: 221064
2014-11-01 22:25:23 +00:00
Craig Topper f2855ade2b Add intrinsics for lzcnt and tzcnt instructions.
llvm-svn: 147263
2011-12-25 06:25:37 +00:00