| Message ID | 87lhb4i82z.fsf@e105548-lin.cambridge.arm.com |
|---|---|
| State | New |
| Headers | show |
On Thu, Oct 15, 2015 at 3:18 PM, Richard Sandiford <richard.sandiford@arm.com> wrote: > builtins-20.c had: > > if (cos((y*=2, -fabs(tan(x/-y)))) != cos((y*=2,tan(x/y)))) > link_error (); > > which is undefined behaviour. The test expected that y had the same > value in x/y and x/-y, but gimplification actually implements the > "obvious" interpretation, multiplying y by 2, using it for one cos call, > then multiplying it by 2 again and using it for the other cos call. > > The file has other (valid) tests that side-effects don't block > optimisation, such as: > > if (cosf((y*=3, -x)) != cosf((y*=3,x))) > link_error (); > > so this patch simply removes this instance. > > Tested on x86_64-linux-gnu, aarch64-linux-gnu and arm-linux-gnueabi. > OK to install? Ok. Thanks, Richard. > Thanks, > Richard > > > gcc/testsuite/ > * gcc.dg/builtins-20.c: Remove undefined behavior. > > diff --git a/gcc/testsuite/gcc.dg/builtins-20.c b/gcc/testsuite/gcc.dg/builtins-20.c > index 43aa71b..2b63428 100644 > --- a/gcc/testsuite/gcc.dg/builtins-20.c > +++ b/gcc/testsuite/gcc.dg/builtins-20.c > @@ -122,7 +122,7 @@ void test2(double x, double y) > if (cos((y*=3, -x)) != cos((y*=3,x))) > link_error (); > > - if (cos((y*=2, -fabs(tan(x/-y)))) != cos((y*=2,tan(x/y)))) > + if (cos(-fabs(tan(x/-y))) != cos(tan(x/y))) > link_error (); > > if (cos(copysign(x,y)) != cos(x)) > @@ -350,7 +350,7 @@ void test2f(float x, float y) > if (cosf((y*=3, -x)) != cosf((y*=3,x))) > link_error (); > > - if (cosf((y*=2, -fabsf(tanf(x/-y)))) != cosf((y*=2,tanf(x/y)))) > + if (cosf(-fabsf(tanf(x/-y))) != cosf(tanf(x/y))) > link_error (); > > if (cosf(copysignf(x,y)) != cosf(x)) > @@ -577,7 +577,7 @@ void test2l(long double x, long double y) > if (cosl((y*=3, -x)) != cosl((y*=3,x))) > link_error (); > > - if (cosl((y*=2, -fabsl(tanl(x/-y)))) != cosl((y*=2,tanl(x/y)))) > + if (cosl(-fabsl(tanl(x/-y))) != cosl(tanl(x/y))) > link_error (); > > if (cosl(copysignl(x,y)) != cosl(x)) >
diff --git a/gcc/testsuite/gcc.dg/builtins-20.c b/gcc/testsuite/gcc.dg/builtins-20.c index 43aa71b..2b63428 100644 --- a/gcc/testsuite/gcc.dg/builtins-20.c +++ b/gcc/testsuite/gcc.dg/builtins-20.c @@ -122,7 +122,7 @@ void test2(double x, double y) if (cos((y*=3, -x)) != cos((y*=3,x))) link_error (); - if (cos((y*=2, -fabs(tan(x/-y)))) != cos((y*=2,tan(x/y)))) + if (cos(-fabs(tan(x/-y))) != cos(tan(x/y))) link_error (); if (cos(copysign(x,y)) != cos(x)) @@ -350,7 +350,7 @@ void test2f(float x, float y) if (cosf((y*=3, -x)) != cosf((y*=3,x))) link_error (); - if (cosf((y*=2, -fabsf(tanf(x/-y)))) != cosf((y*=2,tanf(x/y)))) + if (cosf(-fabsf(tanf(x/-y))) != cosf(tanf(x/y))) link_error (); if (cosf(copysignf(x,y)) != cosf(x)) @@ -577,7 +577,7 @@ void test2l(long double x, long double y) if (cosl((y*=3, -x)) != cosl((y*=3,x))) link_error (); - if (cosl((y*=2, -fabsl(tanl(x/-y)))) != cosl((y*=2,tanl(x/y)))) + if (cosl(-fabsl(tanl(x/-y))) != cosl(tanl(x/y))) link_error (); if (cosl(copysignl(x,y)) != cosl(x))
builtins-20.c had: if (cos((y*=2, -fabs(tan(x/-y)))) != cos((y*=2,tan(x/y)))) link_error (); which is undefined behaviour. The test expected that y had the same value in x/y and x/-y, but gimplification actually implements the "obvious" interpretation, multiplying y by 2, using it for one cos call, then multiplying it by 2 again and using it for the other cos call. The file has other (valid) tests that side-effects don't block optimisation, such as: if (cosf((y*=3, -x)) != cosf((y*=3,x))) link_error (); so this patch simply removes this instance. Tested on x86_64-linux-gnu, aarch64-linux-gnu and arm-linux-gnueabi. OK to install? Thanks, Richard gcc/testsuite/ * gcc.dg/builtins-20.c: Remove undefined behavior.