| Message ID | 20151114071148.GA16647@jaguar.atmel.com |
|---|---|
| State | New |
| Headers | show |
On Sat, 14 Nov 2015, Senthil Kumar Selvaraj wrote: > This patch came out of a discussion held in the gcc mailing list > (https://gcc.gnu.org/ml/gcc/2015-11/msg00067.html). > > The patch restricts folding of conditional exprs with lhs previously > set by a type conversion to occur only if the source of the type > conversion's mode is word mode or smaller. > > Bootstrapped and reg tested on x86_64 (with --enable-languages=c,c++). > > If ok, could you commit please? I don't have commit access. > > Regards > Senthil > > gcc/ChangeLog > > 2015-11-11 Senthil Kumar Selvaraj <senthil_kumar.selvaraj@atmel.com> > > * tree-vrp.c (simplify_cond_using_ranges): Fold only > if innerop's mode is word_mode or smaller. > > > diff --git gcc/tree-vrp.c gcc/tree-vrp.c > index e2393e4..c139bc6 100644 > --- gcc/tree-vrp.c > +++ gcc/tree-vrp.c > @@ -9467,6 +9467,8 @@ simplify_cond_using_ranges (gcond *stmt) > innerop = gimple_assign_rhs1 (def_stmt); > > if (TREE_CODE (innerop) == SSA_NAME > + && (GET_MODE_SIZE(TYPE_MODE(TREE_TYPE(innerop))) > + <= GET_MODE_SIZE(word_mode)) > && !POINTER_TYPE_P (TREE_TYPE (innerop))) > { > value_range *vr = get_value_range (innerop); I thought the result of the discussion was that the transformation is ok if either it is narrowing or it widens but to something no bigger than word_mode. So you should have 2 comparisons, or 1 with a max.
On Sat, Nov 14, 2015 at 09:13:41AM +0100, Marc Glisse wrote: > On Sat, 14 Nov 2015, Senthil Kumar Selvaraj wrote: > > >This patch came out of a discussion held in the gcc mailing list > >(https://gcc.gnu.org/ml/gcc/2015-11/msg00067.html). > > > >The patch restricts folding of conditional exprs with lhs previously > >set by a type conversion to occur only if the source of the type > >conversion's mode is word mode or smaller. > > > >Bootstrapped and reg tested on x86_64 (with --enable-languages=c,c++). > > > >If ok, could you commit please? I don't have commit access. > > > >Regards > >Senthil > > > >gcc/ChangeLog > > > >2015-11-11 Senthil Kumar Selvaraj <senthil_kumar.selvaraj@atmel.com> > > > > * tree-vrp.c (simplify_cond_using_ranges): Fold only > > if innerop's mode is word_mode or smaller. > > > > > >diff --git gcc/tree-vrp.c gcc/tree-vrp.c > >index e2393e4..c139bc6 100644 > >--- gcc/tree-vrp.c > >+++ gcc/tree-vrp.c > >@@ -9467,6 +9467,8 @@ simplify_cond_using_ranges (gcond *stmt) > > innerop = gimple_assign_rhs1 (def_stmt); > > > > if (TREE_CODE (innerop) == SSA_NAME > >+ && (GET_MODE_SIZE(TYPE_MODE(TREE_TYPE(innerop))) > >+ <= GET_MODE_SIZE(word_mode)) > > && !POINTER_TYPE_P (TREE_TYPE (innerop))) > > { > > value_range *vr = get_value_range (innerop); > > I thought the result of the discussion was that the transformation is ok if > either it is narrowing or it widens but to something no bigger than > word_mode. So you should have 2 comparisons, or 1 with a max. Hmm, I came to the opposite conclusion - I thought Richard only okayed "widening upto word-mode", not the narrowing. Richard? Regards Senthil > > -- > Marc Glisse
On November 14, 2015 9:49:28 AM GMT+01:00, Senthil Kumar Selvaraj <senthil_kumar.selvaraj@atmel.com> wrote: >On Sat, Nov 14, 2015 at 09:13:41AM +0100, Marc Glisse wrote: >> On Sat, 14 Nov 2015, Senthil Kumar Selvaraj wrote: >> >> >This patch came out of a discussion held in the gcc mailing list >> >(https://gcc.gnu.org/ml/gcc/2015-11/msg00067.html). >> > >> >The patch restricts folding of conditional exprs with lhs previously >> >set by a type conversion to occur only if the source of the type >> >conversion's mode is word mode or smaller. >> > >> >Bootstrapped and reg tested on x86_64 (with >--enable-languages=c,c++). >> > >> >If ok, could you commit please? I don't have commit access. >> > >> >Regards >> >Senthil >> > >> >gcc/ChangeLog >> > >> >2015-11-11 Senthil Kumar Selvaraj ><senthil_kumar.selvaraj@atmel.com> >> > >> > * tree-vrp.c (simplify_cond_using_ranges): Fold only >> > if innerop's mode is word_mode or smaller. >> > >> > >> >diff --git gcc/tree-vrp.c gcc/tree-vrp.c >> >index e2393e4..c139bc6 100644 >> >--- gcc/tree-vrp.c >> >+++ gcc/tree-vrp.c >> >@@ -9467,6 +9467,8 @@ simplify_cond_using_ranges (gcond *stmt) >> > innerop = gimple_assign_rhs1 (def_stmt); >> > >> > if (TREE_CODE (innerop) == SSA_NAME >> >+ && (GET_MODE_SIZE(TYPE_MODE(TREE_TYPE(innerop))) >> >+ <= GET_MODE_SIZE(word_mode)) >> > && !POINTER_TYPE_P (TREE_TYPE (innerop))) >> > { >> > value_range *vr = get_value_range (innerop); >> >> I thought the result of the discussion was that the transformation is >ok if >> either it is narrowing or it widens but to something no bigger than >> word_mode. So you should have 2 comparisons, or 1 with a max. > >Hmm, I came to the opposite conclusion - I thought Richard only okayed >"widening upto word-mode", not the narrowing. I didn't mean to suggest narrowing is not OK. In fact narrowing is always OK. Richard. >Richard? > >Regards >Senthil >> >> -- >> Marc Glisse
diff --git gcc/tree-vrp.c gcc/tree-vrp.c index e2393e4..c139bc6 100644 --- gcc/tree-vrp.c +++ gcc/tree-vrp.c @@ -9467,6 +9467,8 @@ simplify_cond_using_ranges (gcond *stmt) innerop = gimple_assign_rhs1 (def_stmt); if (TREE_CODE (innerop) == SSA_NAME + && (GET_MODE_SIZE(TYPE_MODE(TREE_TYPE(innerop))) + <= GET_MODE_SIZE(word_mode)) && !POINTER_TYPE_P (TREE_TYPE (innerop))) { value_range *vr = get_value_range (innerop);