Re: [PATCH] D12633: Implement ACLE 2.0 macros of chapters 6.6 and 6.7 for [ARM] and [Aarch64] targets

[Phabricator via cfe-commits]

This revision was automatically updated to reflect the committed changes.
Closed by commit rL249140: Implement ACLE 2.0 macros of chapters 6.6 and 6.7 
for [ARM] and [Aarch64]… (authored by alelab01).

Changed prior to commit:
  http://reviews.llvm.org/D12633?vs=35628&id=36367#toc

Repository:
  rL LLVM

http://reviews.llvm.org/D12633

Files:
  cfe/trunk/include/clang/Basic/LangOptions.def
  cfe/trunk/lib/Basic/Targets.cpp
  cfe/trunk/lib/Frontend/CompilerInvocation.cpp
  cfe/trunk/test/Preprocessor/aarch64-target-features.c
  cfe/trunk/test/Preprocessor/arm-target-features.c

Index: cfe/trunk/include/clang/Basic/LangOptions.def
===
--- cfe/trunk/include/clang/Basic/LangOptions.def
+++ cfe/trunk/include/clang/Basic/LangOptions.def
@@ -146,6 +146,7 @@
 COMPATIBLE_LANGOPT(Deprecated, 1, 0, "__DEPRECATED predefined macro")
 LANGOPT(FastMath  , 1, 0, "__FAST_MATH__ predefined macro")
 LANGOPT(FiniteMathOnly, 1, 0, "__FINITE_MATH_ONLY__ predefined macro")
+LANGOPT(UnsafeFPMath  , 1, 0, "Unsafe Floating Point Math")
 
 BENIGN_LANGOPT(ObjCGCBitmapPrint , 1, 0, "printing of GC's bitmap layout for __weak/__strong ivars")
 
Index: cfe/trunk/test/Preprocessor/arm-target-features.c
===
--- cfe/trunk/test/Preprocessor/arm-target-features.c
+++ cfe/trunk/test/Preprocessor/arm-target-features.c
@@ -32,6 +32,7 @@
 // CHECK-V8-BAREHF: __ARM_FEATURE_DIRECTED_ROUNDING 1
 // CHECK-V8-BAREHF: __ARM_FEATURE_NUMERIC_MAXMIN 1
 // CHECK-V8-BAREHF: __ARM_NEON__ 1
+// CHECK-V8-BAREHF: __ARM_PCS_VFP 1
 // CHECK-V8-BAREHF: __VFP_FP__ 1
 
 // RUN: %clang -target armv8a -mfloat-abi=hard -mfpu=fp-armv8 -x c -E -dM %s | FileCheck --check-prefix=CHECK-V8-BAREHF-FP %s
@@ -85,9 +86,17 @@
 // THUMBV8A-EABI:#define __ARM_ARCH_EXT_IDIV__ 1
 
 // RUN: %clang -target arm-none-linux-gnu -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-DEFS %s
+// CHECK-DEFS:#define __ARM_PCS 1
 // CHECK-DEFS:#define __ARM_SIZEOF_MINIMAL_ENUM 4
 // CHECK-DEFS:#define __ARM_SIZEOF_WCHAR_T 4
 
+// RUN: %clang -target arm-none-linux-gnu -fno-math-errno -fno-signed-zeros\
+// RUN:-fno-trapping-math -fassociative-math -freciprocal-math\
+// RUN:-x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-FASTMATH %s
+// RUN: %clang -target arm-none-linux-gnu -ffast-math -x c -E -dM %s -o -\
+// RUN:| FileCheck --check-prefix=CHECK-FASTMATH %s
+// CHECK-FASTMATH: __ARM_FP_FAST 1
+
 // RUN: %clang -target arm-none-linux-gnu -fshort-wchar -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-SHORTWCHAR %s
 // CHECK-SHORTWCHAR:#define __ARM_SIZEOF_WCHAR_T 2
 
Index: cfe/trunk/test/Preprocessor/aarch64-target-features.c
===
--- cfe/trunk/test/Preprocessor/aarch64-target-features.c
+++ cfe/trunk/test/Preprocessor/aarch64-target-features.c
@@ -30,10 +30,11 @@
 // CHECK: __ARM_FP16_ARGS 1
 // CHECK: __ARM_FP16_FORMAT_IEEE 1
 // CHECK-NOT: __ARM_FP_FAST 1
-// CHECK: __ARM_FP_FENV_ROUNDING 1
 // CHECK: __ARM_NEON 1
 // CHECK: __ARM_NEON_FP 0xE
 // CHECK: __ARM_PCS_AAPCS64 1
+// CHECK-NOT: __ARM_PCS 1
+// CHECK-NOT: __ARM_PCS_VFP 1
 // CHECK-NOT: __ARM_SIZEOF_MINIMAL_ENUM 1
 // CHECK-NOT: __ARM_SIZEOF_WCHAR_T 2
 
@@ -50,6 +51,9 @@
 // RUN: %clang -target arm64-none-linux-gnu -march=armv8-a+crc -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-CRC32 %s
 // CHECK-CRC32: __ARM_FEATURE_CRC32 1
 
+// RUN: %clang -target aarch64-none-linux-gnu -fno-math-errno -fno-signed-zeros\
+// RUN:-fno-trapping-math -fassociative-math -freciprocal-math\
+// RUN:-x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-FASTMATH %s
 // RUN: %clang -target aarch64-none-linux-gnu -ffast-math -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-FASTMATH %s
 // RUN: %clang -target arm64-none-linux-gnu -ffast-math -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-FASTMATH %s
 // CHECK-FASTMATH: __ARM_FP_FAST 1
Index: cfe/trunk/lib/Basic/Targets.cpp
===
--- cfe/trunk/lib/Basic/Targets.cpp
+++ cfe/trunk/lib/Basic/Targets.cpp
@@ -4751,6 +4751,9 @@
 // ACLE 6.4.6 Q (saturation) flag
 if (DSP || SAT)
   Builder.defineMacro("__ARM_FEATURE_QBIT", "1");
+
+if (Opts.UnsafeFPMath)
+  Builder.defineMacro("__ARM_FP_FAST", "1");
   }
 
   void getTargetBuiltins(const Builtin::Info *&Records,
@@ -5204,7 +5207,7 @@
 Builder.defineMacro("__ARM_ARCH_PROFILE", "'A'");
 
 Builder.defineMacro("__ARM_64BIT_STATE", "1");
-Builder.defineMacro("__ARM_PCS_AAPCS64");
+Builder.defineMacro("__ARM_PCS_AAPCS64", "1");
 Builder.defineMacro("__ARM_ARCH_ISA_A64", "1");
 
 Builder.defineMacro("__ARM_FEATURE_CLZ", "1");
@@ -5225,11 +5228,8 @@
 Builder.defineMacro("__ARM_FP16_FORMAT_IEEE", "1");
 Builder.defineMacro("__ARM_FP16_ARGS", "1");
 
-if (Opts.FastMath || Opts.Finite

Re: [PATCH] D12633: Implement ACLE 2.0 macros of chapters 6.6 and 6.7 for [ARM] and [Aarch64] targets

[Renato Golin via cfe-commits]

rengolin accepted this revision.
rengolin added a comment.
This revision is now accepted and ready to land.

Sorry, I've been redirected elsewhere for a few days.

I agree that this is the best option, since that's the meaning of the flag, 
anyway.

LGTM.

--renato


http://reviews.llvm.org/D12633



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Re: [PATCH] D12633: Implement ACLE 2.0 macros of chapters 6.6 and 6.7 for [ARM] and [Aarch64] targets

[Richard Barton via cfe-commits]

richard.barton.arm added a comment.

What do you think about this Renato? Although Alexandros has added a LangOption 
which is strictly speaking to do with CodeGen rather than Lang, I think this is 
the only pragmatica way to do this without needing re-engineering work to 
expose the codegen options to this phase in clang.

Are you and I able to make the call to let Alexandros commit, or do you think 
we ought to seek guidance from elsewhere? Do you have an idea who we could go 
to?


http://reviews.llvm.org/D12633



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Re: [PATCH] D12633: Implement ACLE 2.0 macros of chapters 6.6 and 6.7 for [ARM] and [Aarch64] targets

[Alexandros Lamprineas via cfe-commits]

labrinea added a comment.

ping


http://reviews.llvm.org/D12633



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Re: [PATCH] D12633: Implement ACLE 2.0 macros of chapters 6.6 and 6.7 for [ARM] and [Aarch64] targets

[Alexandros Lamprineas via cfe-commits]

labrinea added a comment.

In http://reviews.llvm.org/D12633#252758, @labrinea wrote:

> @t.p.northover I think we should not be defining _ARM_FP_FENV_ROUNDING on 
> neither of ARM and AArch64 targets since "-frounding-math" is not available 
> on clang: clang/llvm don't support C99 FP rounding mode pragmas (FENV_ACCESS 
> etc) 
>
> > @t.p.northover : "Ah, that constant folding is definitely a problem. 
> > Changing it sounds reasonable.
>
> > Tim."
>


(attaching Tim's comment since it was missing from the phabricator thread)


http://reviews.llvm.org/D12633



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Re: [PATCH] D12633: Implement ACLE 2.0 macros of chapters 6.6 and 6.7 for [ARM] and [Aarch64] targets

[Tim Northover via cfe-commits]

On 24 September 2015 at 07:53, Alexandros Lamprineas
 wrote:
> @t.p.northover I think we should not be defining _ARM_FP_FENV_ROUNDING on 
> neither of ARM and AArch64 targets since "-frounding-math" is not available 
> on clang: clang/llvm don't support C99 FP rounding mode pragmas (FENV_ACCESS 
> etc) 

Ah, that constant folding is definitely a problem. Changing it sounds
reasonable.

Tim.
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Re: [PATCH] D12633: Implement ACLE 2.0 macros of chapters 6.6 and 6.7 for [ARM] and [Aarch64] targets

[Richard Barton via cfe-commits]

richard.barton.arm added a comment.

In the overall approach, whilst this is the pragmatic approach to get the job 
done, it clearly takes liberties with the definition of LangOpt as this your 
new flag is most certainly a CodeGenOpt rather than a LangOpt. I'd like to see 
what the others say as I don't see a better solution.



Comment at: lib/Frontend/CompilerInvocation.cpp:1711
@@ -1710,1 +1710,3 @@
   Args.hasArg(OPT_cl_fast_relaxed_math);
+  Opts.UnsafeFPMath = Args.hasArg(OPT_menable_unsafe_fp_math) ||
+  Args.hasArg(OPT_cl_unsafe_math_optimizations) ||

labrinea wrote:
> richard.barton.arm wrote:
> > What happens if I do -menable-unsafe-fp-math then 
> > -mno-enable-unsafe-fp-math? I don't think you have enough regression tests.
> Well there is no such flag (-mno-enable-unsafe-fp-math) but probably what you 
> want to say is that the order of the front-end flags matters. In 
> **llvm/tools/clang/test/Driver/fast-math.c** there are tests checking whether 
> "-menable-unsafe-fp-math" is correctly set depending on the order of the 
> front-end flags. I could modify my tests so that they pass cc1 flags. Then we 
> would be checking if _ARM_FP_FAST gets defined in the presence of 
> "-menable-unsafe-fp-math". Would that be preferable?
Ok - I did not realise that by this point in the code we know this has been 
taken care of. If that argument processing is already covered by tests then 
there is no need to add more and I retract my suggestion.


http://reviews.llvm.org/D12633



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Re: [PATCH] D12633: Implement ACLE 2.0 macros of chapters 6.6 and 6.7 for [ARM] and [Aarch64] targets

[Alexandros Lamprineas via cfe-commits]

labrinea added inline comments.


Comment at: lib/Frontend/CompilerInvocation.cpp:1711
@@ -1710,1 +1710,3 @@
   Args.hasArg(OPT_cl_fast_relaxed_math);
+  Opts.UnsafeFPMath = Args.hasArg(OPT_menable_unsafe_fp_math) ||
+  Args.hasArg(OPT_cl_unsafe_math_optimizations) ||

richard.barton.arm wrote:
> What happens if I do -menable-unsafe-fp-math then -mno-enable-unsafe-fp-math? 
> I don't think you have enough regression tests.
Well there is no such flag (-mno-enable-unsafe-fp-math) but probably what you 
want to say is that the order of the front-end flags matters. In 
**llvm/tools/clang/test/Driver/fast-math.c** there are tests checking whether 
"-menable-unsafe-fp-math" is correctly set depending on the order of the 
front-end flags. I could modify my tests so that they pass cc1 flags. Then we 
would be checking if _ARM_FP_FAST gets defined in the presence of 
"-menable-unsafe-fp-math". Would that be preferable?


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Re: [PATCH] D12633: Implement ACLE 2.0 macros of chapters 6.6 and 6.7 for [ARM] and [Aarch64] targets

[Richard Barton via cfe-commits]

richard.barton.arm added inline comments.


Comment at: lib/Frontend/CompilerInvocation.cpp:1711
@@ -1710,1 +1710,3 @@
   Args.hasArg(OPT_cl_fast_relaxed_math);
+  Opts.UnsafeFPMath = Args.hasArg(OPT_menable_unsafe_fp_math) ||
+  Args.hasArg(OPT_cl_unsafe_math_optimizations) ||

What happens if I do -menable-unsafe-fp-math then -mno-enable-unsafe-fp-math? I 
don't think you have enough regression tests.


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Re: [PATCH] D12633: Implement ACLE 2.0 macros of chapters 6.6 and 6.7 for [ARM] and [Aarch64] targets

[Alexandros Lamprineas via cfe-commits]

labrinea updated this revision to Diff 35628.
labrinea added a comment.

@t.p.northover I think we should not be defining _ARM_FP_FENV_ROUNDING on 
neither of ARM and AArch64 targets since "-frounding-math" is not available on 
clang: clang/llvm don't support C99 FP rounding mode pragmas (FENV_ACCESS etc) 


@rengolin Clang translates frontend GCC compliant flags to cc1 flags:

- -fno-honor-infinities => -menable-no-infs
- -fno-honor-nans => -menable-no-nans
- AND( -fassociative-math, -freciprocal-math, -fno-signed-zeros, 
-fno-trapping-math, -fno-math-errno ) => -menable-unsafe-fp-math

Those flags seem to affect an LLVM IR in two ways:

- function attributes (no-infs-fp-math = yes|no, no-nans-fp-math = yes|no, 
unsafe-fp-math = yes|no)
- fast-math flags used with generated fp-math operators (this doc summarizes 
the LLVM-IR fast-math flags )

I think we should not be checking **Opts.FiniteMathOnly** since it only 
indicates whether optimizations assume the arguments and result to be +/-inf. 
We should not be checking **Opts.FastMath** either since it might be the case 
where //-menable-unsafe-fp-math// is set but //-ffast-math// is not set. Then 
the user would rely on _ARM_FP_FAST being absent but in reality the backend 
would emit unsafe fp math IR. My patch introduces a new lang option to handle 
this case.


http://reviews.llvm.org/D12633

Files:
  include/clang/Basic/LangOptions.def
  lib/Basic/Targets.cpp
  lib/Frontend/CompilerInvocation.cpp
  test/Preprocessor/aarch64-target-features.c
  test/Preprocessor/arm-target-features.c

Index: test/Preprocessor/arm-target-features.c
===
--- test/Preprocessor/arm-target-features.c
+++ test/Preprocessor/arm-target-features.c
@@ -32,6 +32,7 @@
 // CHECK-V8-BAREHF: __ARM_FEATURE_DIRECTED_ROUNDING 1
 // CHECK-V8-BAREHF: __ARM_FEATURE_NUMERIC_MAXMIN 1
 // CHECK-V8-BAREHF: __ARM_NEON__ 1
+// CHECK-V8-BAREHF: __ARM_PCS_VFP 1
 // CHECK-V8-BAREHF: __VFP_FP__ 1
 
 // RUN: %clang -target armv8a -mfloat-abi=hard -mfpu=fp-armv8 -x c -E -dM %s | FileCheck --check-prefix=CHECK-V8-BAREHF-FP %s
@@ -85,9 +86,17 @@
 // THUMBV8A-EABI:#define __ARM_ARCH_EXT_IDIV__ 1
 
 // RUN: %clang -target arm-none-linux-gnu -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-DEFS %s
+// CHECK-DEFS:#define __ARM_PCS 1
 // CHECK-DEFS:#define __ARM_SIZEOF_MINIMAL_ENUM 4
 // CHECK-DEFS:#define __ARM_SIZEOF_WCHAR_T 4
 
+// RUN: %clang -target arm-none-linux-gnu -fno-math-errno -fno-signed-zeros\
+// RUN:-fno-trapping-math -fassociative-math -freciprocal-math\
+// RUN:-x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-FASTMATH %s
+// RUN: %clang -target arm-none-linux-gnu -ffast-math -x c -E -dM %s -o -\
+// RUN:| FileCheck --check-prefix=CHECK-FASTMATH %s
+// CHECK-FASTMATH: __ARM_FP_FAST 1
+
 // RUN: %clang -target arm-none-linux-gnu -fshort-wchar -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-SHORTWCHAR %s
 // CHECK-SHORTWCHAR:#define __ARM_SIZEOF_WCHAR_T 2
 
Index: test/Preprocessor/aarch64-target-features.c
===
--- test/Preprocessor/aarch64-target-features.c
+++ test/Preprocessor/aarch64-target-features.c
@@ -30,10 +30,11 @@
 // CHECK: __ARM_FP16_ARGS 1
 // CHECK: __ARM_FP16_FORMAT_IEEE 1
 // CHECK-NOT: __ARM_FP_FAST 1
-// CHECK: __ARM_FP_FENV_ROUNDING 1
 // CHECK: __ARM_NEON 1
 // CHECK: __ARM_NEON_FP 0xE
 // CHECK: __ARM_PCS_AAPCS64 1
+// CHECK-NOT: __ARM_PCS 1
+// CHECK-NOT: __ARM_PCS_VFP 1
 // CHECK-NOT: __ARM_SIZEOF_MINIMAL_ENUM 1
 // CHECK-NOT: __ARM_SIZEOF_WCHAR_T 2
 
@@ -50,6 +51,9 @@
 // RUN: %clang -target arm64-none-linux-gnu -march=armv8-a+crc -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-CRC32 %s
 // CHECK-CRC32: __ARM_FEATURE_CRC32 1
 
+// RUN: %clang -target aarch64-none-linux-gnu -fno-math-errno -fno-signed-zeros\
+// RUN:-fno-trapping-math -fassociative-math -freciprocal-math\
+// RUN:-x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-FASTMATH %s
 // RUN: %clang -target aarch64-none-linux-gnu -ffast-math -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-FASTMATH %s
 // RUN: %clang -target arm64-none-linux-gnu -ffast-math -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-FASTMATH %s
 // CHECK-FASTMATH: __ARM_FP_FAST 1
Index: lib/Frontend/CompilerInvocation.cpp
===
--- lib/Frontend/CompilerInvocation.cpp
+++ lib/Frontend/CompilerInvocation.cpp
@@ -1708,6 +1708,9 @@
   Opts.FiniteMathOnly = Args.hasArg(OPT_ffinite_math_only) ||
   Args.hasArg(OPT_cl_finite_math_only) ||
   Args.hasArg(OPT_cl_fast_relaxed_math);
+  Opts.UnsafeFPMath = Args.hasArg(OPT_menable_unsafe_fp_math) ||
+  Args.hasArg(OPT_cl_unsafe_math_optimizations) ||
+  Args.hasArg(OPT_cl_fast_relaxed_math);
 
   Opts.RetainCommentsF

Re: [PATCH] D12633: Implement ACLE 2.0 macros of chapters 6.6 and 6.7 for [ARM] and [Aarch64] targets

[Renato Golin via cfe-commits]

rengolin added a comment.

In http://reviews.llvm.org/D12633#250612, @labrinea wrote:

> __ARM_FP_FAST is defined to 1 if floating-point optimizations may occur such 
> that the computed results are different from those prescribed by the order of 
> operations according to the C standard. Examples of such optimizations would 
> be reassociation of expressions to reduce depth, and replacement of a 
> division by constant with multiplication by its reciprocal.


This seems to be specific to the order of operations, which is related to 
"-funsafe-math-optimizations", but not necessarily the other three. If Clang 
has, and sets the same flags as GCC docs imply, we should only set the macro 
for that one flag.


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Re: [PATCH] D12633: Implement ACLE 2.0 macros of chapters 6.6 and 6.7 for [ARM] and [Aarch64] targets

[Tim Northover via cfe-commits]

t.p.northover added a comment.

I can't explain the Opts.C99 (fesetround is provided by conforming C++11 
implementations too), but I think I was just trying to capture the fact that 
decent hosted platforms support fesetround but freestanding ones don't (not 
having any library).

Supporting "C89 but we also have math.h" (or more realistically "C++03 with 
math.h") wasn't really something that interested me: users should be encouraged 
to write to standards.

Cheers.

Tim.


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Re: [PATCH] D12633: Implement ACLE 2.0 macros of chapters 6.6 and 6.7 for [ARM] and [Aarch64] targets

[Alexandros Lamprineas via cfe-commits]

labrinea added a comment.

GCC online docs 
  state:

> -ffast-math

>  Might allow some programs designed to not be too dependent on IEEE behavior 
> for floating-point to run faster, or die trying. Sets 
> -funsafe-math-optimizations, -ffinite-math-only, and -fno-trapping-math.

> 

> -funsafe-math-optimizations

>  Allow optimizations that may be give incorrect results for certain IEEE 
> inputs.

> 

> -ffinite-math-only

> Allow optimizations for floating-point arithmetic that assume that arguments 
> and results are not NaNs or +-Infs.

> 

> -fno-trapping-math

>  Allow the compiler to assume that floating-point arithmetic will not 
> generate traps on any inputs. This is useful, for example, when running a 
> program using IEEE "non-stop" floating-point arithmetic.


Does this mean, define _ARM_FP_FAST when all these three flags are set 
(-funsafe-math-optimizations, -ffinite-math-only, and -fno-trapping-math)? We 
are currently checking ("-ffast-math" or "-ffinite-math-only").

ACLE docs state:

> __ARM_FP_FAST is defined to 1 if floating-point optimizations may occur such 
> that the computed results are different from those prescribed by the order of 
> operations according to the C standard. Examples of such optimizations would 
> be reassociation of expressions to reduce depth, and replacement of a 
> division by constant with multiplication by its reciprocal.



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Re: [PATCH] D12633: Implement ACLE 2.0 macros of chapters 6.6 and 6.7 for [ARM] and [Aarch64] targets

[Renato Golin via cfe-commits]

rengolin added a comment.

In http://reviews.llvm.org/D12633#249966, @richard.barton.arm wrote:

> I think clang ought to take a conservative stance when setting these flags.


Exactly my point. This is one of the few examples where being pragmatic may 
lead to big headaches in the future. :)


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Re: [PATCH] D12633: Implement ACLE 2.0 macros of chapters 6.6 and 6.7 for [ARM] and [Aarch64] targets

[Richard Barton via cfe-commits]

richard.barton.arm added a comment.

Yes - I would be interested in knowing the rationale behind the original 
AArch64 setting of __ARM_FP_FPENV_ROUNDING.

I also question whether our pre-conditions for __ARM_FP_FAST are sufficient. 
There are many -f... options relating to maths operations, are these two the 
only ones that might not preserve the order of operations? I think clang ought 
to take a conservative stance when setting these flags.


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Re: [PATCH] D12633: Implement ACLE 2.0 macros of chapters 6.6 and 6.7 for [ARM] and [Aarch64] targets

[Renato Golin via cfe-commits]

rengolin added a comment.

Richard,

The original patch was following a lot from the AArch64, so I suspect we should 
first fix the AArch64 side, so that we can follow in a similar way. I don't 
want to have two different behaviour for ARM and AArch64 regarding macros and 
ACLE support. But I also don't think we should include AArch64 code with this 
patch.

cheers,
--renato


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Re: [PATCH] D12633: Implement ACLE 2.0 macros of chapters 6.6 and 6.7 for [ARM] and [Aarch64] targets

[Alexandros Lamprineas via cfe-commits]

labrinea added a comment.

@rsmith @t.p.northover could you please give us some feedback on this? Thanks.


http://reviews.llvm.org/D12633



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Re: [PATCH] D12633: Implement ACLE 2.0 macros of chapters 6.6 and 6.7 for [ARM] and [Aarch64] targets

[Alexandros Lamprineas via cfe-commits]

labrinea updated this revision to Diff 35223.
labrinea added a comment.

Patch updated.


http://reviews.llvm.org/D12633

Files:
  lib/Basic/Targets.cpp
  test/Preprocessor/aarch64-target-features.c
  test/Preprocessor/arm-target-features.c

Index: test/Preprocessor/arm-target-features.c
===
--- test/Preprocessor/arm-target-features.c
+++ test/Preprocessor/arm-target-features.c
@@ -32,6 +32,7 @@
 // CHECK-V8-BAREHF: __ARM_FEATURE_DIRECTED_ROUNDING 1
 // CHECK-V8-BAREHF: __ARM_FEATURE_NUMERIC_MAXMIN 1
 // CHECK-V8-BAREHF: __ARM_NEON__ 1
+// CHECK-V8-BAREHF: __ARM_PCS_VFP 1
 // CHECK-V8-BAREHF: __VFP_FP__ 1
 
 // RUN: %clang -target armv8a -mfloat-abi=hard -mfpu=fp-armv8 -x c -E -dM %s | 
FileCheck --check-prefix=CHECK-V8-BAREHF-FP %s
@@ -85,9 +86,13 @@
 // THUMBV8A-EABI:#define __ARM_ARCH_EXT_IDIV__ 1
 
 // RUN: %clang -target arm-none-linux-gnu -x c -E -dM %s -o - | FileCheck 
--check-prefix=CHECK-DEFS %s
+// CHECK-DEFS:#define __ARM_PCS 1
 // CHECK-DEFS:#define __ARM_SIZEOF_MINIMAL_ENUM 4
 // CHECK-DEFS:#define __ARM_SIZEOF_WCHAR_T 4
 
+// RUN: %clang -target arm-none-linux-gnu -ffast-math -x c -E -dM %s -o - | 
FileCheck --check-prefix=CHECK-FASTMATH %s
+// CHECK-FASTMATH: __ARM_FP_FAST 1
+
 // RUN: %clang -target arm-none-linux-gnu -fshort-wchar -x c -E -dM %s -o - | 
FileCheck --check-prefix=CHECK-SHORTWCHAR %s
 // CHECK-SHORTWCHAR:#define __ARM_SIZEOF_WCHAR_T 2
 
Index: test/Preprocessor/aarch64-target-features.c
===
--- test/Preprocessor/aarch64-target-features.c
+++ test/Preprocessor/aarch64-target-features.c
@@ -34,6 +34,8 @@
 // CHECK: __ARM_NEON 1
 // CHECK: __ARM_NEON_FP 0xE
 // CHECK: __ARM_PCS_AAPCS64 1
+// CHECK-NOT: __ARM_PCS 1
+// CHECK-NOT: __ARM_PCS_VFP 1
 // CHECK-NOT: __ARM_SIZEOF_MINIMAL_ENUM 1
 // CHECK-NOT: __ARM_SIZEOF_WCHAR_T 2
 
Index: lib/Basic/Targets.cpp
===
--- lib/Basic/Targets.cpp
+++ lib/Basic/Targets.cpp
@@ -4762,6 +4762,10 @@
 // ACLE 6.4.6 Q (saturation) flag
 if (hasDSP || hasSAT)
   Builder.defineMacro("__ARM_FEATURE_QBIT", "1");
+
+// ACLE 6.6 Floating-point model
+if (Opts.FastMath || Opts.FiniteMathOnly)
+  Builder.defineMacro("__ARM_FP_FAST", "1");
   }
 
   void getTargetBuiltins(const Builtin::Info *&Records,
@@ -5215,7 +5219,7 @@
 Builder.defineMacro("__ARM_ARCH_PROFILE", "'A'");
 
 Builder.defineMacro("__ARM_64BIT_STATE", "1");
-Builder.defineMacro("__ARM_PCS_AAPCS64");
+Builder.defineMacro("__ARM_PCS_AAPCS64", "1");
 Builder.defineMacro("__ARM_ARCH_ISA_A64", "1");
 
 Builder.defineMacro("__ARM_FEATURE_CLZ", "1");
@@ -5237,7 +5241,7 @@
 Builder.defineMacro("__ARM_FP16_ARGS", "1");
 
 if (Opts.FastMath || Opts.FiniteMathOnly)
-  Builder.defineMacro("__ARM_FP_FAST");
+  Builder.defineMacro("__ARM_FP_FAST", "1");
 
 if (Opts.C99 && !Opts.Freestanding)
   Builder.defineMacro("__ARM_FP_FENV_ROUNDING");


Index: test/Preprocessor/arm-target-features.c
===
--- test/Preprocessor/arm-target-features.c
+++ test/Preprocessor/arm-target-features.c
@@ -32,6 +32,7 @@
 // CHECK-V8-BAREHF: __ARM_FEATURE_DIRECTED_ROUNDING 1
 // CHECK-V8-BAREHF: __ARM_FEATURE_NUMERIC_MAXMIN 1
 // CHECK-V8-BAREHF: __ARM_NEON__ 1
+// CHECK-V8-BAREHF: __ARM_PCS_VFP 1
 // CHECK-V8-BAREHF: __VFP_FP__ 1
 
 // RUN: %clang -target armv8a -mfloat-abi=hard -mfpu=fp-armv8 -x c -E -dM %s | FileCheck --check-prefix=CHECK-V8-BAREHF-FP %s
@@ -85,9 +86,13 @@
 // THUMBV8A-EABI:#define __ARM_ARCH_EXT_IDIV__ 1
 
 // RUN: %clang -target arm-none-linux-gnu -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-DEFS %s
+// CHECK-DEFS:#define __ARM_PCS 1
 // CHECK-DEFS:#define __ARM_SIZEOF_MINIMAL_ENUM 4
 // CHECK-DEFS:#define __ARM_SIZEOF_WCHAR_T 4
 
+// RUN: %clang -target arm-none-linux-gnu -ffast-math -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-FASTMATH %s
+// CHECK-FASTMATH: __ARM_FP_FAST 1
+
 // RUN: %clang -target arm-none-linux-gnu -fshort-wchar -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-SHORTWCHAR %s
 // CHECK-SHORTWCHAR:#define __ARM_SIZEOF_WCHAR_T 2
 
Index: test/Preprocessor/aarch64-target-features.c
===
--- test/Preprocessor/aarch64-target-features.c
+++ test/Preprocessor/aarch64-target-features.c
@@ -34,6 +34,8 @@
 // CHECK: __ARM_NEON 1
 // CHECK: __ARM_NEON_FP 0xE
 // CHECK: __ARM_PCS_AAPCS64 1
+// CHECK-NOT: __ARM_PCS 1
+// CHECK-NOT: __ARM_PCS_VFP 1
 // CHECK-NOT: __ARM_SIZEOF_MINIMAL_ENUM 1
 // CHECK-NOT: __ARM_SIZEOF_WCHAR_T 2
 
Index: lib/Basic/Targets.cpp
===
--- lib/Basic/Targets.cpp
+++ lib/Basic/Targets.cpp
@@ -4762,6 +4762,10 @@
 // ACLE 6.4.6 Q (saturation) flag
 if (hasDSP || hasSAT)
   Builder.defineMacro("__ARM_F

Re: [PATCH] D12633: Implement ACLE 2.0 macros of chapters 6.6 and 6.7 for [ARM] and [Aarch64] targets

[Richard Barton via cfe-commits]

richard.barton.arm added a comment.

Hi all

I am uncomfortable with this patch for a number of reasons. These macros seem 
to me to be defined by the ACLE as describing the behaviour of the combination 
of library and compiler. For example, the __STDC_IEC_599__ macro would need 
some standards compliance from the compiler in terms of optimisations on 
floating point functions, and from the libraries in terms of the behaviour of 
the fp functions there. Thus, I don't think it is safe for clang to define this 
macro for all ARM compilation regardless of which library is being used to link 
with. Perhaps I have misunderstood that one - so it would be worth running this 
past Tim directly as the __ARM_FP_FENV_ROUNDING definition comes from his 
original AArch64 patches from early 2013.

If I am right - then clang would want to adopt an approach similar to GCC's 
described here https://gcc.gnu.org/onlinedocs/cpp/Common-Predefined-Macros.html 
(grep for __GCC_IEC_559) where the compiler sets a macro which presumably is 
read by a compliant c library header which then sets the ACLE macro.

However, there are multiple bug reports in the area of FP math - see 
https://llvm.org/bugs/show_bug.cgi?id=8100 - which makes me think that for 
Clang to really be ACLE compliant, we should not be defining any of these 
macros apart from __ARM_FP_FAST. Additionally a bit of research on the devs 
list suggest that LLVM does not support signaling NaNs e.g. 
http://lists.llvm.org/pipermail/llvm-dev/2014-April/071699.html and 
http://lists.llvm.org/pipermail/llvm-dev/2014-August/075749.html from last year

I suggest that the patch needs to be resubmitted without the setting of 
__ARM_FP_FENV_ROUNDING, __STDC_IEC_559 and __SUPPORT_SNAN, and that the setting 
of __ARM_FP_FENV_ROUNDING in the aarch64 target be clarified.


http://reviews.llvm.org/D12633



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Re: [PATCH] D12633: Implement ACLE 2.0 macros of chapters 6.6 and 6.7 for [ARM] and [Aarch64] targets

[Renato Golin via cfe-commits]

rengolin added reviewers: rsmith, t.p.northover.
rengolin added a comment.

Adding Richard Smith, as he was the one choosing C99/!freestanding for runtime 
rounding.



Comment at: lib/Basic/Targets.cpp:4790
@@ -4779,1 +4789,3 @@
+if (!Opts.C11)
+  Builder.defineMacro("__SUPPORT_SNAN__", "1");
   }

labrinea wrote:
> rengolin wrote:
> > Er, well, the ACLE doc says it wasn't adopted in C11, but that doesn't mean 
> > that it was present in all others, just that there is a proposal for C11 
> > which wasn't accepted.
> > 
> > I think this macro needs some other mechanism to be set, and unless 
> > Clang/LLVM supports signaling NANs unconditionally, we shouldn't add it.
> Maybe we could skip this macro in this patch? @richard.barton.arm
If this item sparks controversy, we should keep it out. For now, I'm interested 
in what Tim and Richard(s) have to say.


http://reviews.llvm.org/D12633



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Re: [PATCH] D12633: Implement ACLE 2.0 macros of chapters 6.6 and 6.7 for [ARM] and [Aarch64] targets

[Alexandros Lamprineas via cfe-commits]

labrinea added inline comments.


Comment at: lib/Basic/Targets.cpp:4785
@@ +4784,3 @@
+if (Opts.C99 && !Opts.Freestanding) {
+  Builder.defineMacro("__ARM_FP_FENV_ROUNDING", "1");
+  Builder.defineMacro("__STDC_IEC_559__", "1");

rengolin wrote:
> I'm not convinced by the runtime rounding being depending on C99, or why it's 
> not possible in freestanding environments.
I copied the same logic from AArch64.


Comment at: lib/Basic/Targets.cpp:4786
@@ +4785,3 @@
+  Builder.defineMacro("__ARM_FP_FENV_ROUNDING", "1");
+  Builder.defineMacro("__STDC_IEC_559__", "1");
+}

Shall we define this unconditionally?


Comment at: lib/Basic/Targets.cpp:4790
@@ -4779,1 +4789,3 @@
+if (!Opts.C11)
+  Builder.defineMacro("__SUPPORT_SNAN__", "1");
   }

rengolin wrote:
> Er, well, the ACLE doc says it wasn't adopted in C11, but that doesn't mean 
> that it was present in all others, just that there is a proposal for C11 
> which wasn't accepted.
> 
> I think this macro needs some other mechanism to be set, and unless 
> Clang/LLVM supports signaling NANs unconditionally, we shouldn't add it.
Maybe we could skip this macro in this patch? @richard.barton.arm


Comment at: lib/Basic/Targets.cpp:5270
@@ +5269,3 @@
+if (Opts.C99 && !Opts.Freestanding) {
+  Builder.defineMacro("__ARM_FP_FENV_ROUNDING", "1");
+  Builder.defineMacro("__STDC_IEC_559__", "1");

rengolin wrote:
> same comments as above.
This was present already.


http://reviews.llvm.org/D12633



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Re: [PATCH] D12633: Implement ACLE 2.0 macros of chapters 6.6 and 6.7 for [ARM] and [Aarch64] targets

[Renato Golin via cfe-commits]

rengolin added inline comments.


Comment at: lib/Basic/Targets.cpp:4785
@@ +4784,3 @@
+if (Opts.C99 && !Opts.Freestanding) {
+  Builder.defineMacro("__ARM_FP_FENV_ROUNDING", "1");
+  Builder.defineMacro("__STDC_IEC_559__", "1");

I'm not convinced by the runtime rounding being depending on C99, or why it's 
not possible in freestanding environments.


Comment at: lib/Basic/Targets.cpp:4790
@@ -4779,1 +4789,3 @@
+if (!Opts.C11)
+  Builder.defineMacro("__SUPPORT_SNAN__", "1");
   }

Er, well, the ACLE doc says it wasn't adopted in C11, but that doesn't mean 
that it was present in all others, just that there is a proposal for C11 which 
wasn't accepted.

I think this macro needs some other mechanism to be set, and unless Clang/LLVM 
supports signaling NANs unconditionally, we shouldn't add it.


Comment at: lib/Basic/Targets.cpp:5270
@@ +5269,3 @@
+if (Opts.C99 && !Opts.Freestanding) {
+  Builder.defineMacro("__ARM_FP_FENV_ROUNDING", "1");
+  Builder.defineMacro("__STDC_IEC_559__", "1");

same comments as above.


http://reviews.llvm.org/D12633



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Re: [PATCH] D12633: Implement ACLE 2.0 macros of chapters 6.6 and 6.7 for [ARM] and [Aarch64] targets

[Alexandros Lamprineas via cfe-commits]

labrinea added a comment.

Ping


http://reviews.llvm.org/D12633



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[PATCH] D12633: Implement ACLE 2.0 macros of chapters 6.6 and 6.7 for [ARM] and [Aarch64] targets

[Alexandros Lamprineas via cfe-commits]

labrinea created this revision.
labrinea added reviewers: rengolin, richard.barton.arm.
labrinea added a subscriber: cfe-commits.
Herald added subscribers: rengolin, aemerson.

Added the remaining macros and corresponding regression tests.

http://reviews.llvm.org/D12633

Files:
  lib/Basic/Targets.cpp
  test/Preprocessor/aarch64-target-features.c
  test/Preprocessor/arm-target-features.c

Index: test/Preprocessor/arm-target-features.c
===
--- test/Preprocessor/arm-target-features.c
+++ test/Preprocessor/arm-target-features.c
@@ -32,6 +32,7 @@
 // CHECK-V8-BAREHF: __ARM_FEATURE_DIRECTED_ROUNDING 1
 // CHECK-V8-BAREHF: __ARM_FEATURE_NUMERIC_MAXMIN 1
 // CHECK-V8-BAREHF: __ARM_NEON__ 1
+// CHECK-V8-BAREHF: __ARM_PCS_VFP 1
 // CHECK-V8-BAREHF: __VFP_FP__ 1
 
 // RUN: %clang -target armv8a -mfloat-abi=hard -mfpu=fp-armv8 -x c -E -dM %s | FileCheck --check-prefix=CHECK-V8-BAREHF-FP %s
@@ -85,8 +86,20 @@
 // THUMBV8A-EABI:#define __ARM_ARCH_EXT_IDIV__ 1
 
 // RUN: %clang -target arm-none-linux-gnu -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-DEFS %s
+// CHECK-DEFS:#define __ARM_FP_FENV_ROUNDING 1
+// CHECK-DEFS:#define __ARM_PCS 1
 // CHECK-DEFS:#define __ARM_SIZEOF_MINIMAL_ENUM 4
 // CHECK-DEFS:#define __ARM_SIZEOF_WCHAR_T 4
+// CHECK-DEFS:#define __STDC_IEC_559__ 1
+
+// RUN: %clang -target arm-none-linux-gnu -std=c99 -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-C99 %s
+// CHECK-C99: __SUPPORT_SNAN__ 1
+
+// RUN: %clang -target arm-none-linux-gnu -std=c11 -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-C11 %s
+// CHECK-C11-NOT: __SUPPORT_SNAN__ 1
+
+// RUN: %clang -target arm-none-linux-gnu -ffast-math -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-FASTMATH %s
+// CHECK-FASTMATH: __ARM_FP_FAST 1
 
 // RUN: %clang -target arm-none-linux-gnu -fshort-wchar -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-SHORTWCHAR %s
 // CHECK-SHORTWCHAR:#define __ARM_SIZEOF_WCHAR_T 2
Index: test/Preprocessor/aarch64-target-features.c
===
--- test/Preprocessor/aarch64-target-features.c
+++ test/Preprocessor/aarch64-target-features.c
@@ -34,12 +34,23 @@
 // CHECK: __ARM_NEON 1
 // CHECK: __ARM_NEON_FP 0xE
 // CHECK: __ARM_PCS_AAPCS64 1
+// CHECK-NOT: __ARM_PCS 1
+// CHECK-NOT: __ARM_PCS_VFP 1
 // CHECK-NOT: __ARM_SIZEOF_MINIMAL_ENUM 1
 // CHECK-NOT: __ARM_SIZEOF_WCHAR_T 2
+// CHECK: __STDC_IEC_559__ 1
 
 // RUN: %clang -target aarch64_be-eabi -x c -E -dM %s -o - | FileCheck %s -check-prefix CHECK-BIGENDIAN
 // CHECK-BIGENDIAN: __ARM_BIG_ENDIAN 1
 
+// RUN: %clang -target aarch64-none-linux-gnu -std=c99 -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-C99 %s
+// RUN: %clang -target arm64-none-linux-gnu -std=c99 -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-C99 %s
+// CHECK-C99: __SUPPORT_SNAN__ 1
+
+// RUN: %clang -target aarch64-none-linux-gnu -std=c11 -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-C11 %s
+// RUN: %clang -target arm64-none-linux-gnu -std=c11 -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-C11 %s
+// CHECK-C11-NOT: __SUPPORT_SNAN__ 1
+
 // RUN: %clang -target aarch64-none-linux-gnu -march=armv8-a+crypto -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-CRYPTO %s
 // RUN: %clang -target arm64-none-linux-gnu -march=armv8-a+crypto -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-CRYPTO %s
 // CHECK-CRYPTO: __ARM_FEATURE_CRYPTO 1
Index: lib/Basic/Targets.cpp
===
--- lib/Basic/Targets.cpp
+++ lib/Basic/Targets.cpp
@@ -4776,6 +4776,18 @@
 // ACLE 6.4.6 Q (saturation) flag
 if (hasDSP || hasSAT)
   Builder.defineMacro("__ARM_FEATURE_QBIT", "1");
+
+// ACLE 6.6 Floating-point model
+if (Opts.FastMath || Opts.FiniteMathOnly)
+  Builder.defineMacro("__ARM_FP_FAST", "1");
+
+if (Opts.C99 && !Opts.Freestanding) {
+  Builder.defineMacro("__ARM_FP_FENV_ROUNDING", "1");
+  Builder.defineMacro("__STDC_IEC_559__", "1");
+}
+
+if (!Opts.C11)
+  Builder.defineMacro("__SUPPORT_SNAN__", "1");
   }
 
   void getTargetBuiltins(const Builtin::Info *&Records,
@@ -5229,7 +5241,7 @@
 Builder.defineMacro("__ARM_ARCH_PROFILE", "'A'");
 
 Builder.defineMacro("__ARM_64BIT_STATE", "1");
-Builder.defineMacro("__ARM_PCS_AAPCS64");
+Builder.defineMacro("__ARM_PCS_AAPCS64", "1");
 Builder.defineMacro("__ARM_ARCH_ISA_A64", "1");
 
 Builder.defineMacro("__ARM_FEATURE_CLZ", "1");
@@ -5250,11 +5262,17 @@
 Builder.defineMacro("__ARM_FP16_FORMAT_IEEE", "1");
 Builder.defineMacro("__ARM_FP16_ARGS", "1");
 
+// ACLE 6.6 Floating-point model
 if (Opts.FastMath || Opts.FiniteMathOnly)
-  Builder.defineMacro("__ARM_FP_FAST");
+  Builder.defineMacro("__ARM_FP_FAST", "1");
+
+if (Opts.C99 && !Opts.Freestanding) {
+  Builder.defineMacro("__ARM_FP_FENV_ROUNDING", "1");
+  Builder.defineMacro("__STDC_IEC_559__",