Message ID | 20220211101348.GO2646553@tucnak |
---|---|
State | New |
Headers | show |
Series | c++: Fix up constant expression __builtin_convertvector folding [PR104472] | expand |
On 2/11/22 05:13, Jakub Jelinek wrote: > Hi! > > The following testcase ICEs, because due to the -frounding-math > fold_const_call fails, which is it returns NULL, and returning NULL from > cxx_eval* is wrong, all the callers rely on them to either return folded > value or original with *non_constant_p = true. > > The following patch does that, and additionally falls through into the > default case where there is diagnostics for the !ctx->quiet case too. > > Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk? OK. > 2022-02-11 Jakub Jelinek <jakub@redhat.com> > > PR c++/104472 > * constexpr.cc (cxx_eval_internal_function) <case IFN_VEC_CONVERT>: > Only return fold_const_call result if it is non-NULL. Otherwise > fall through into the default: case to return t, set *non_constant_p > and emit diagnostics if needed. > > * g++.dg/cpp0x/constexpr-104472.C: New test. > > --- gcc/cp/constexpr.cc.jj 2022-02-08 20:15:33.997295271 +0100 > +++ gcc/cp/constexpr.cc 2022-02-10 12:33:48.243321592 +0100 > @@ -1840,13 +1840,10 @@ cxx_eval_internal_function (const conste > false, non_constant_p, > overflow_p); > if (TREE_CODE (arg) == VECTOR_CST) > - return fold_const_call (CFN_VEC_CONVERT, TREE_TYPE (t), arg); > - else > - { > - *non_constant_p = true; > - return t; > - } > + if (tree r = fold_const_call (CFN_VEC_CONVERT, TREE_TYPE (t), arg)) > + return r; > } > + /* FALLTHRU */ > > default: > if (!ctx->quiet) > --- gcc/testsuite/g++.dg/cpp0x/constexpr-104472.C.jj 2022-02-10 12:44:09.869720657 +0100 > +++ gcc/testsuite/g++.dg/cpp0x/constexpr-104472.C 2022-02-10 12:46:25.881838766 +0100 > @@ -0,0 +1,9 @@ > +// PR c++/104472 > +// { dg-options "-O2 -frounding-math" } > +// { dg-add-options float16 } > +// { dg-require-effective-target float16 } > + > +typedef short __attribute__((__vector_size__ (16))) V; > +typedef _Float16 __attribute__((__vector_size__ (16))) F; > + > +V v = __builtin_convertvector (__builtin_convertvector ((V){5534}, F), V) < 8; > > Jakub >
--- gcc/cp/constexpr.cc.jj 2022-02-08 20:15:33.997295271 +0100 +++ gcc/cp/constexpr.cc 2022-02-10 12:33:48.243321592 +0100 @@ -1840,13 +1840,10 @@ cxx_eval_internal_function (const conste false, non_constant_p, overflow_p); if (TREE_CODE (arg) == VECTOR_CST) - return fold_const_call (CFN_VEC_CONVERT, TREE_TYPE (t), arg); - else - { - *non_constant_p = true; - return t; - } + if (tree r = fold_const_call (CFN_VEC_CONVERT, TREE_TYPE (t), arg)) + return r; } + /* FALLTHRU */ default: if (!ctx->quiet) --- gcc/testsuite/g++.dg/cpp0x/constexpr-104472.C.jj 2022-02-10 12:44:09.869720657 +0100 +++ gcc/testsuite/g++.dg/cpp0x/constexpr-104472.C 2022-02-10 12:46:25.881838766 +0100 @@ -0,0 +1,9 @@ +// PR c++/104472 +// { dg-options "-O2 -frounding-math" } +// { dg-add-options float16 } +// { dg-require-effective-target float16 } + +typedef short __attribute__((__vector_size__ (16))) V; +typedef _Float16 __attribute__((__vector_size__ (16))) F; + +V v = __builtin_convertvector (__builtin_convertvector ((V){5534}, F), V) < 8;