| Message ID | ZboIYMC/12V1YSKi@tucnak |
|---|---|
| State | New |
| Headers | show |
| Series | simplify-rtx: Fix up last argument to simplify_gen_unary [PR113656] | expand |
On Wed, 31 Jan 2024, Jakub Jelinek wrote: > Hi! > > When simplifying e.g. (float_truncate:SF (float_truncate:DF (reg:XF)) > or (float_truncate:SF (float_extend:XF (reg:DF)) etc. into > (float_truncate:SF (reg:XF)) or (float_truncate:SF (reg:DF)) we call > simplify_gen_unary with incorrect op_mode argument, it should be > the argument's mode, but we call it with the outer mode instead. > As these are all floating point operations, the argument always > has non-VOIDmode and so we can just use that mode (as done in similar > simplifications a few lines later), but neither FLOAT_TRUNCATE nor > FLOAT_EXTEND are operations that should have the same modes of operand > and result. This bug hasn't been a problem for years because normally > op_mode is used only if the mode of op is VOIDmode, otherwise it is > redundant, but r10-2139 added an assertion in some spots that op_mode > is right even in such cases. > > Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk? OK. > 2024-01-31 Jakub Jelinek <jakub@redhat.com> > > PR rtl-optimization/113656 > * simplify-rtx.cc (simplify_context::simplify_unary_operation_1) > <case FLOAT_TRUNCATE>: Fix up last argument to simplify_gen_unary. > > * gcc.target/i386/pr113656.c: New test. > > --- gcc/simplify-rtx.cc.jj 2024-01-03 11:51:32.828713189 +0100 > +++ gcc/simplify-rtx.cc 2024-01-30 19:34:30.516934480 +0100 > @@ -1305,7 +1305,7 @@ simplify_context::simplify_unary_operati > > GET_MODE_UNIT_SIZE (mode) > ? FLOAT_TRUNCATE : FLOAT_EXTEND, > mode, > - XEXP (op, 0), mode); > + XEXP (op, 0), GET_MODE (XEXP (op, 0))); > > /* (float_truncate (float x)) is (float x) */ > if ((GET_CODE (op) == FLOAT || GET_CODE (op) == UNSIGNED_FLOAT) > --- gcc/testsuite/gcc.target/i386/pr113656.c.jj 2024-01-30 19:38:29.029608721 +0100 > +++ gcc/testsuite/gcc.target/i386/pr113656.c 2024-01-30 19:37:10.519703443 +0100 > @@ -0,0 +1,12 @@ > +/* PR rtl-optimization/113656 */ > +/* { dg-do compile } */ > +/* { dg-options "-O3 -frounding-math -funsafe-math-optimizations -mavx512fp16 -mavx512vl" } */ > + > +_Float16 a[8]; > + > +void > +foo () > +{ > + for (int i = 0; i < 8; i++) > + a[i] = i - 8.4; > +} > > Jakub > >
--- gcc/simplify-rtx.cc.jj 2024-01-03 11:51:32.828713189 +0100 +++ gcc/simplify-rtx.cc 2024-01-30 19:34:30.516934480 +0100 @@ -1305,7 +1305,7 @@ simplify_context::simplify_unary_operati > GET_MODE_UNIT_SIZE (mode) ? FLOAT_TRUNCATE : FLOAT_EXTEND, mode, - XEXP (op, 0), mode); + XEXP (op, 0), GET_MODE (XEXP (op, 0))); /* (float_truncate (float x)) is (float x) */ if ((GET_CODE (op) == FLOAT || GET_CODE (op) == UNSIGNED_FLOAT) --- gcc/testsuite/gcc.target/i386/pr113656.c.jj 2024-01-30 19:38:29.029608721 +0100 +++ gcc/testsuite/gcc.target/i386/pr113656.c 2024-01-30 19:37:10.519703443 +0100 @@ -0,0 +1,12 @@ +/* PR rtl-optimization/113656 */ +/* { dg-do compile } */ +/* { dg-options "-O3 -frounding-math -funsafe-math-optimizations -mavx512fp16 -mavx512vl" } */ + +_Float16 a[8]; + +void +foo () +{ + for (int i = 0; i < 8; i++) + a[i] = i - 8.4; +}