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)
<https://llvm.org/bugs/show_bug.cgi?id=8100>
@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 <http://llvm.org/docs/LangRef.html#fastmath>)
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.RetainCommentsFromSystemHeaders =
Args.hasArg(OPT_fretain_comments_from_system_headers);
Index: lib/Basic/Targets.cpp
===================================================================
--- lib/Basic/Targets.cpp
+++ lib/Basic/Targets.cpp
@@ -4762,6 +4762,9 @@
// ACLE 6.4.6 Q (saturation) flag
if (hasDSP || hasSAT)
Builder.defineMacro("__ARM_FEATURE_QBIT", "1");
+
+ if (Opts.UnsafeFPMath)
+ Builder.defineMacro("__ARM_FP_FAST", "1");
}
void getTargetBuiltins(const Builtin::Info *&Records,
@@ -5215,7 +5218,7 @@
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");
@@ -5236,11 +5239,8 @@
Builder.defineMacro("__ARM_FP16_FORMAT_IEEE", "1");
Builder.defineMacro("__ARM_FP16_ARGS", "1");
- if (Opts.FastMath || Opts.FiniteMathOnly)
- Builder.defineMacro("__ARM_FP_FAST");
-
- if (Opts.C99 && !Opts.Freestanding)
- Builder.defineMacro("__ARM_FP_FENV_ROUNDING");
+ if (Opts.UnsafeFPMath)
+ Builder.defineMacro("__ARM_FP_FAST", "1");
Builder.defineMacro("__ARM_SIZEOF_WCHAR_T", Opts.ShortWChar ? "2" : "4");
Index: include/clang/Basic/LangOptions.def
===================================================================
--- include/clang/Basic/LangOptions.def
+++ 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")
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