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

[Palmer Dabbelt <palmer@dabbelt.com>]

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" } } */
>>