Re: [PATCH] RISC-V missing __builtin_lceil and __builtin_lfloor

[Kevin Lee <kevinl@rivosinc.com>]

> Kevin: Looks like this got corrupted, possibly from copy/paste into
> gmail.  I resurrect it, but there's a floating-point test failure in
> gfortran.  Looks like it predates this, but I'm trying to bisect it to
> at least have a root cause before just ignoring it.  I've got this
> floating around on a branch and hopefully that'll remind me to commit
> it after I sort that out.

Currently, the testsuite doesn't show additional failures. It seems
like the corrupted patch caused the issue. I will post the clean patch
as v2. Thank you for the review!

On Sun, Oct 2, 2022 at 1:47 PM Kevin Lee <kevinl@rivosinc.com> wrote:
>
> Thank you for the update Palmer. I'll certainly look into the corrupted patch issue and the floating-point test failure in gfortran.
>
> On Sun, Oct 2, 2022 at 1:42 PM Palmer Dabbelt <palmer@dabbelt.com> wrote:
>>
>> On Sat, 17 Sep 2022 14:16:13 PDT (-0700), Kito Cheng wrote:
>> > LGTM, thanks, I guess I just missed this before
>>
>> No worries, I'd just stubmled on it looking through old stuff.
>>
>> Kevin: Looks like this got corrupted, possibly from copy/paste into
>> gmail.  I resurrect it, but there's a floating-point test failure in
>> gfortran.  Looks like it predates this, but I'm trying to bisect it to
>> at least have a root cause before just ignoring it.  I've got this
>> floating around on a branch and hopefully that'll remind me to commit
>> it after I sort that out.
>>
>> >
>> > Palmer Dabbelt <palmer@dabbelt.com> 於 2022年9月17日 週六 23:07 寫道：
>> >
>> >> On Mon, 15 Aug 2022 17:44:35 PDT (-0700), kevinl@rivosinc.com wrote:
>> >> > Hello,
>> >> > Currently, __builtin_lceil and __builtin_lfloor doesn't generate an
>> >> > existing instruction fcvt, but rather calls ceil and floor from the
>> >> > library. This patch adds the missing iterator and attributes for lceil
>> >> and
>> >> > lfloor to produce the optimized code.
>> >> >  The test cases check the correct generation of the fcvt instruction for
>> >> > float/double to int/long/long long. Passed the test in riscv-linux.
>> >> > Could this patch be committed?
>> >>
>> >> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com>
>> >> Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
>> >>
>> >> Not sure if Kito had any comments for this one, but it looks good to me.
>> >>
>> >> > gcc/ChangeLog:
>> >> >        Michael Collison  <collison@rivosinc.com>
>> >> >         * config/riscv/riscv.md (RINT): Add iterator for lceil and
>> >> lround.
>> >> >         (rint_pattern): Add ceil and floor.
>> >> >         (rint_rm): Add rup and rdn.
>> >> >
>> >> > gcc/testsuite/ChangeLog:
>> >> >         Kevin Lee  <kevinl@rivosinc.com>
>> >> >         * gcc.target/riscv/lfloor-lceil.c: New test.
>> >> > ---
>> >> >  gcc/config/riscv/riscv.md                     | 13 ++-
>> >> >  gcc/testsuite/gcc.target/riscv/lfloor-lceil.c | 79 +++++++++++++++++++
>> >> >  2 files changed, 88 insertions(+), 4 deletions(-)
>> >> >  create mode 100644 gcc/testsuite/gcc.target/riscv/lfloor-lceil.c
>> >> >
>> >> > diff --git a/gcc/config/riscv/riscv.md b/gcc/config/riscv/riscv.md
>> >> > index c6399b1389e..070004fa7fe 100644
>> >> > --- a/gcc/config/riscv/riscv.md
>> >> > +++ b/gcc/config/riscv/riscv.md
>> >> > @@ -43,6 +43,9 @@ (define_c_enum "unspec" [
>> >> >    UNSPEC_LRINT
>> >> >    UNSPEC_LROUND
>> >> >
>> >> > +  UNSPEC_LCEIL
>> >> > +  UNSPEC_LFLOOR
>> >> > +
>> >> >    ;; Stack tie
>> >> >    UNSPEC_TIE
>> >> >  ])
>> >> > @@ -345,10 +348,12 @@ (define_mode_attr UNITMODE [(SF "SF") (DF "DF")])
>> >> >  ;; the controlling mode.
>> >> >  (define_mode_attr HALFMODE [(DF "SI") (DI "SI") (TF "DI")])
>> >> >
>> >> > -;; Iterator and attributes for floating-point rounding instructions.
>> >> > -(define_int_iterator RINT [UNSPEC_LRINT UNSPEC_LROUND])
>> >> > -(define_int_attr rint_pattern [(UNSPEC_LRINT "rint") (UNSPEC_LROUND
>> >> > "round")])
>> >> > -(define_int_attr rint_rm [(UNSPEC_LRINT "dyn") (UNSPEC_LROUND "rmm")])
>> >> > +;; Iterator and attributes for floating-point rounding instructions.f
>> >> > +(define_int_iterator RINT [UNSPEC_LRINT UNSPEC_LROUND UNSPEC_LCEIL
>> >> > UNSPEC_LFLOOR])
>> >> > +(define_int_attr rint_pattern [(UNSPEC_LRINT "rint") (UNSPEC_LROUND
>> >> > "round")
>> >> > +                             (UNSPEC_LCEIL "ceil") (UNSPEC_LFLOOR
>> >> > "floor")])
>> >> > +(define_int_attr rint_rm [(UNSPEC_LRINT "dyn") (UNSPEC_LROUND "rmm")
>> >> > +                        (UNSPEC_LCEIL "rup") (UNSPEC_LFLOOR "rdn")])
>> >> >
>> >> >  ;; Iterator and attributes for quiet comparisons.
>> >> >  (define_int_iterator QUIET_COMPARISON [UNSPEC_FLT_QUIET
>> >> UNSPEC_FLE_QUIET])
>> >> > diff --git a/gcc/testsuite/gcc.target/riscv/lfloor-lceil.c
>> >> > b/gcc/testsuite/gcc.target/riscv/lfloor-lceil.c
>> >> > new file mode 100644
>> >> > index 00000000000..4d81c12cefa
>> >> > --- /dev/null
>> >> > +++ b/gcc/testsuite/gcc.target/riscv/lfloor-lceil.c
>> >> > @@ -0,0 +1,79 @@
>> >> > +/* { dg-do compile } */
>> >> > +/* { dg-options "-march=rv64gc -mabi=lp64d" } */
>> >> > +/* { dg-skip-if "" { *-*-* } { "-O0" "-Og" } } */
>> >> > +
>> >> > +int
>> >> > +ceil1(float i)
>> >> > +{
>> >> > +  return __builtin_lceil(i);
>> >> > +}
>> >> > +
>> >> > +long
>> >> > +ceil2(float i)
>> >> > +{
>> >> > +  return __builtin_lceil(i);
>> >> > +}
>> >> > +
>> >> > +long long
>> >> > +ceil3(float i)
>> >> > +{
>> >> > +  return __builtin_lceil(i);
>> >> > +}
>> >> > +
>> >> > +int
>> >> > +ceil4(double i)
>> >> > +{
>> >> > +  return __builtin_lceil(i);
>> >> > +}
>> >> > +
>> >> > +long
>> >> > +ceil5(double i)
>> >> > +{
>> >> > +  return __builtin_lceil(i);
>> >> > +}
>> >> > +
>> >> > +long long
>> >> > +ceil6(double i)
>> >> > +{
>> >> > +  return __builtin_lceil(i);
>> >> > +}
>> >> > +
>> >> > +int
>> >> > +floor1(float i)
>> >> > +{
>> >> > +  return __builtin_lfloor(i);
>> >> > +}
>> >> > +
>> >> > +long
>> >> > +floor2(float i)
>> >> > +{
>> >> > +  return __builtin_lfloor(i);
>> >> > +}
>> >> > +
>> >> > +long long
>> >> > +floor3(float i)
>> >> > +{
>> >> > +  return __builtin_lfloor(i);
>> >> > +}
>> >> > +
>> >> > +int
>> >> > +floor4(double i)
>> >> > +{
>> >> > +  return __builtin_lfloor(i);
>> >> > +}
>> >> > +
>> >> > +long
>> >> > +floor5(double i)
>> >> > +{
>> >> > +  return __builtin_lfloor(i);
>> >> > +}
>> >> > +
>> >> > +long long
>> >> > +floor6(double i)
>> >> > +{
>> >> > +  return __builtin_lfloor(i);
>> >> > +}
>> >> > +
>> >> > +/* { dg-final { scan-assembler-times "fcvt.l.s" 6 } } */
>> >> > +/* { dg-final { scan-assembler-times "fcvt.l.d" 6 } } */
>> >> > +/* { dg-final { scan-assembler-not "call" } } */
>> >>