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Differential D59843

[PowerPC] Add support for __dcbf builtin
ClosedPublic

Authored by saghir on Mar 26 2019, 1:47 PM.

Details

Reviewers
kbarton
nemanjai
stefanp
lei
amyk
hfinkel
Commits
rL359517: Add __builtin_dcbf support for PPC
rG3962d6da1779: Add __builtin_dcbf support for PPC
rC359517: Add __builtin_dcbf support for PPC
Summary

This patch is intended to add support for __dcbf builtin.

Purpose:
Data Cache Block Flush: Copies the contents of a modified block from the data cache to main memory and flushes the copy from the data cache.

Prototype:
void __dcbf(const void* addr);

Diff Detail

Repository
rC Clang

Event Timeline

saghir created this revision.Mar 26 2019, 1:47 PM
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saghir edited reviewers, added: hfinkel; removed: llvm-commits.Mar 26 2019, 1:51 PM
saghir added a subscriber: llvm-commits.
saghir updated this revision to Diff 192355.Mar 26 2019, 2:17 PM

Updated test in dcbf.ll

stefanp accepted this revision.Mar 28 2019, 11:19 AM

Minor nit that can be fixed when this patch is committed.
LGTM.

llvm/test/CodeGen/PowerPC/dcbf.ll
10 ↗(On Diff #192355)

nit:
I don't think that you need to check the basic block label here. It does not have anything to do with what you are trying to test.

This revision is now accepted and ready to land.Mar 28 2019, 11:19 AM
amyk accepted this revision.Mar 28 2019, 11:26 AM

This looks good to me.

saghir updated this revision to Diff 193957.Apr 5 2019, 1:25 PM

Removed check for basic block in dcbf.ll

steven.zhang added a subscriber: steven.zhang.Apr 7 2019, 6:08 PM

It would be great if we could add some documentation for these new added builtins, to make more people to know what we have done. i.e. clang/docs/LanguageExtensions.rst

saghir updated this revision to Diff 194442.Apr 9 2019, 9:50 PM

Added documentation in clang/docs/LanguageExtensions.rst

amyk accepted this revision.Apr 10 2019, 1:52 PM

I think this still looks good to me, with the addition of the documentation.

steven.zhang added a comment.Apr 10 2019, 8:17 PM

Looks good, just one minor comments.
It seems that, we have already had the PowerPC section in the rst. It would be better to put them together.

PowerPC Language Extensions
------------------------------

Set the Floating Point Rounding Mode
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
saghir updated this revision to Diff 195094.Apr 14 2019, 10:22 PM

Moved cache builtins section to PowerPC Language extensions in LanguageExtensions.rst

steven.zhang added a comment.Apr 15 2019, 3:29 AM

I am ok now for the doc part change. Thank you.

stefanp accepted this revision.Apr 15 2019, 10:59 AM

Looks good to me.
Then only thing I noticed was that in the description in the LanguageExtensions.rst file you use plural to refer to the chache builtins. Of course, you only added one builtin but I know that in the future you plan to add more builtins of the same type so I wouldn't worry about that wording now.

saghir added a comment.Apr 15 2019, 1:49 PM
In D59843#1467249, @stefanp wrote:

Looks good to me.
Then only thing I noticed was that in the description in the LanguageExtensions.rst file you use plural to refer to the chache builtins. Of course, you only added one builtin but I know that in the future you plan to add more builtins of the same type so I wouldn't worry about that wording now.

That is precisely the reason for using plural since we plan to add support for more cache builtins.

Closed by commit rC359517: Add __builtin_dcbf support for PPC (authored by saghir). · Explain WhyApr 29 2019, 4:23 PM
This revision was automatically updated to reflect the committed changes.
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Revision Contents

PathSize
docs/
25 lines
include/
clang/
Basic/
3 lines
test/
CodeGen/
47 lines

Diff 197218

docs/LanguageExtensions.rst

Show First 20 Lines • Show All 2,442 Lines • ▼ Show 20 LinesThe effective values for mode are:
- 1 - round to zero - 1 - round to zero
- 2 - round to +infinity - 2 - round to +infinity
- 3 - round to -infinity - 3 - round to -infinity
Note that the mode argument will modulo 4, so if the integer argument is greater Note that the mode argument will modulo 4, so if the integer argument is greater
than 3, it will only use the least significant two bits of the mode. than 3, it will only use the least significant two bits of the mode.
Namely, ``__builtin_setrnd(102))`` is equal to ``__builtin_setrnd(2)``. Namely, ``__builtin_setrnd(102))`` is equal to ``__builtin_setrnd(2)``.
PowerPC cache builtins
^^^^^^^^^^^^^^^^^^^^^^
The PowerPC architecture specifies instructions implementing cache operations.
Clang provides builtins that give direct programmer access to these cache
instructions.
Currently the following builtins are implemented in clang:
``__builtin_dcbf`` copies the contents of a modified block from the data cache
to main memory and flushes the copy from the data cache.
**Syntax**:
.. code-block:: c
void __dcbf(const void* addr); /* Data Cache Block Flush */
**Example of Use**:
.. code-block:: c
int a = 1;
__builtin_dcbf (&a);
Extensions for Static Analysis Extensions for Static Analysis
============================== ==============================
Clang supports additional attributes that are useful for documenting program Clang supports additional attributes that are useful for documenting program
invariants and rules for static analysis tools, such as the `Clang Static invariants and rules for static analysis tools, such as the `Clang Static
Analyzer <https://clang-analyzer.llvm.org/>`_. These attributes are documented Analyzer <https://clang-analyzer.llvm.org/>`_. These attributes are documented
in the analyzer's `list of source-level annotations in the analyzer's `list of source-level annotations
<https://clang-analyzer.llvm.org/annotations.html>`_. <https://clang-analyzer.llvm.org/annotations.html>`_.
▲ Show 20 Lines • Show All 564 Lines • Show Last 20 Lines

include/clang/Basic/BuiltinsPPC.def

Show First 20 Lines • Show All 472 Lines • ▼ Show 20 Lines
// Vector int128 (un)pack // Vector int128 (un)pack
BUILTIN(__builtin_unpack_vector_int128, "ULLiV1LLLii", "") BUILTIN(__builtin_unpack_vector_int128, "ULLiV1LLLii", "")
BUILTIN(__builtin_pack_vector_int128, "V1LLLiULLiULLi", "") BUILTIN(__builtin_pack_vector_int128, "V1LLLiULLiULLi", "")
// Set the floating point rounding mode // Set the floating point rounding mode
BUILTIN(__builtin_setrnd, "di", "") BUILTIN(__builtin_setrnd, "di", "")
// Cache built-ins
BUILTIN(__builtin_dcbf, "vvC*", "")
// FIXME: Obviously incomplete. // FIXME: Obviously incomplete.
#undef BUILTIN #undef BUILTIN

test/CodeGen/builtins-ppc-cache.c

// RUN: %clang_cc1 -triple powerpc64le-unknown-linux-gnu -emit-llvm \
// RUN: -o - %s | FileCheck %s
int A;
int B[5];
float C;
float D[5];
double E;
double F[5];
void func(int a, int b[], float c, float d[], double e, double f[]) {
__builtin_dcbf (&a);
// CHECK: @llvm.ppc.dcbf(i8*
__builtin_dcbf (&A);
// CHECK: @llvm.ppc.dcbf(i8*
__builtin_dcbf (&b[2]);
// CHECK: @llvm.ppc.dcbf(i8*
__builtin_dcbf (&B[2]);
// CHECK: @llvm.ppc.dcbf(i8*
__builtin_dcbf (&c);
// CHECK: @llvm.ppc.dcbf(i8*
__builtin_dcbf (&C);
// CHECK: @llvm.ppc.dcbf(i8*
__builtin_dcbf (&d[2]);
// CHECK: @llvm.ppc.dcbf(i8*
__builtin_dcbf (&D[2]);
// CHECK: @llvm.ppc.dcbf(i8*
__builtin_dcbf (&e);
// CHECK: @llvm.ppc.dcbf(i8*
__builtin_dcbf (&E);
// CHECK: @llvm.ppc.dcbf(i8*
__builtin_dcbf (&f[0]);
// CHECK: @llvm.ppc.dcbf(i8*
__builtin_dcbf (&F[0]);
// CHECK: @llvm.ppc.dcbf(i8*
}