84a9ec2ff1
There are currently two options that are used to tell the compiler to perform unsafe floating-point optimizations: '-ffast-math' and '-funsafe-math-optimizations'. '-ffast-math' is enabled by default. It automatically enables the driver option '-menable-unsafe-fp-math'. Below is a table illustrating the special operations enabled automatically by '-ffast-math', '-funsafe-math-optimizations' and '-menable-unsafe-fp-math' respectively. Special Operations -ffast-math -funsafe-math-optimizations -menable-unsafe-fp-math MathErrno 0 1 1 FiniteMathOnly 1 0 0 AllowFPReassoc 1 1 1 NoSignedZero 1 1 1 AllowRecip 1 1 1 ApproxFunc 1 1 1 RoundingMath 0 0 0 UnsafeFPMath 1 0 1 FPContract fast on on '-ffast-math' enables '-fno-math-errno', '-ffinite-math-only', '-funsafe-math-optimzations' and sets 'FpContract' to 'fast'. The driver option '-menable-unsafe-fp-math' enables the same special options than '-funsafe-math-optimizations'. This is redundant. We propose to remove the driver option '-menable-unsafe-fp-math' and use instead, the setting of the special operations to set the function attribute 'unsafe-fp-math'. This attribute will be enabled only if those special operations are enabled and if 'FPContract' is either 'fast' or set to the default value. Differential Revision: https://reviews.llvm.org/D135097
76 lines
3.2 KiB
C++
76 lines
3.2 KiB
C++
// RUN: %clang_cc1 -triple x86_64-linux-gnu -fsyntax-only -DCHECK_ERROR %s -verify
|
|
|
|
float function_scope(float a) {
|
|
#pragma float_control(precise, on) junk // expected-warning {{extra tokens at end of '#pragma float_control' - ignored}}
|
|
return a;
|
|
}
|
|
|
|
// Ok, at namespace scope.
|
|
namespace foo {
|
|
#pragma float_control(push)
|
|
#pragma float_control(pop)
|
|
}
|
|
|
|
// Ok, within a language linkage specification.
|
|
extern "C" {
|
|
#pragma float_control(push)
|
|
#pragma float_control(pop)
|
|
}
|
|
|
|
// Same.
|
|
extern "C++" {
|
|
#pragma float_control(push)
|
|
#pragma float_control(pop)
|
|
}
|
|
|
|
#ifdef CHECK_ERROR
|
|
// Ok at file scope.
|
|
#pragma float_control(push)
|
|
#pragma float_control(pop)
|
|
#pragma float_control(precise, on, push)
|
|
void check_stack() {
|
|
// Not okay within a function declaration.
|
|
#pragma float_control(push) // expected-error {{can only appear at file or namespace scope or within a language linkage specification}}
|
|
#pragma float_control(pop) // expected-error {{can only appear at file or namespace scope or within a language linkage specification}}
|
|
#pragma float_control(precise, on, push) // expected-error {{can only appear at file or namespace scope or within a language linkage specification}}
|
|
#pragma float_control(except, on, push) // expected-error {{can only appear at file or namespace scope or within a language linkage specification}}
|
|
#pragma float_control(except, on, push, junk) // expected-error {{float_control is malformed}}
|
|
return;
|
|
}
|
|
#endif
|
|
|
|
// RUN: %clang_cc1 -triple x86_64-linux-gnu -fdenormal-fp-math=preserve-sign,preserve-sign -fsyntax-only %s -DDEFAULT -verify
|
|
// RUN: %clang_cc1 -triple x86_64-linux-gnu -fsyntax-only %s -ffp-contract=fast -DPRECISE -verify
|
|
// RUN: %clang_cc1 -triple x86_64-linux-gnu -fsyntax-only %s -ffp-contract=off -frounding-math -ffp-exception-behavior=strict -DSTRICT -verify
|
|
// RUN: %clang_cc1 -triple x86_64-linux-gnu -menable-no-infs -menable-no-nans -funsafe-math-optimizations -fno-signed-zeros -mreassociate -freciprocal-math -ffp-contract=fast -ffast-math -ffinite-math-only -fsyntax-only %s -DFAST -verify
|
|
double a = 0.0;
|
|
double b = 1.0;
|
|
|
|
#ifdef STRICT
|
|
#pragma float_control(precise, off) // expected-error {{'#pragma float_control(precise, off)' is illegal when except is enabled}}
|
|
#else
|
|
#ifndef FAST
|
|
#pragma STDC FENV_ACCESS ON
|
|
#pragma float_control(precise, off) // expected-error {{'#pragma float_control(precise, off)' is illegal when except is enabled}}
|
|
#endif
|
|
#endif
|
|
|
|
#pragma float_control(precise, on)
|
|
#pragma float_control(except, on) // OK
|
|
#ifndef STRICT
|
|
#pragma float_control(except, on)
|
|
#pragma float_control(precise, off) // expected-error {{'#pragma float_control(precise, off)' is illegal when except is enabled}}
|
|
#endif
|
|
int main() {
|
|
#ifdef STRICT
|
|
#pragma float_control(precise, off) // expected-error {{'#pragma float_control(precise, off)' is illegal when except is enabled}}
|
|
#else
|
|
#pragma float_control(precise, off) // expected-error {{'#pragma float_control(precise, off)' is illegal when except is enabled}}
|
|
#endif
|
|
#pragma float_control(except, on)
|
|
// error: '#pragma float_control(except, on)' is illegal when precise is disabled
|
|
double x = b / a; // only used for fp flag setting
|
|
if (a == a) // only used for fp flag setting
|
|
return 0; //(int)x;
|
|
}
|