Re: [PATCH][GCC][AArch64] Inline calls to lrint when possible

[Tamar Christina <Tamar.Christina@arm.com>]

Hi Christophe,

Thanks, I've committed a fix to the testcase.

Tamar
________________________________________
From: Christophe Lyon <christophe.lyon@linaro.org>
Sent: Monday, June 12, 2017 1:10:38 PM
To: Tamar Christina
Cc: GCC Patches; nd; Richard Earnshaw; Marcus Shawcroft
Subject: Re: [PATCH][GCC][AArch64] Inline calls to lrint when possible

Hi Tamar,

On 8 June 2017 at 18:50, James Greenhalgh <james.greenhalgh@arm.com> wrote:
> On Wed, Jun 07, 2017 at 12:38:27PM +0100, Tamar Christina wrote:
>> Hi All,
>>
>> This patch allows the inlining of lrint when -fno-math-errno
>> assuming that errno does not need to be set when the rounded value
>> is not representable as a long.
>>
>> The case
>>
>> void f(double *a, long *b, double x)
>> {
>>       *a = __builtin_rint(x);
>>       *b = __builtin_lrint(x);
>> }
>>
>> now generates with -fno-math-errno:
>>
>> f:
>>       frintx  d0, d0
>>       fcvtzs  x2, d0
>>       str     d0, [x0]
>>       str     x2, [x1]
>>       ret
>>
>> When the flag is not used the same function call is emitted as before:
>>
>> f:
>>       stp     x29, x30, [sp, -32]!
>>       frintx  d1, d0
>>       add     x29, sp, 0
>>       str     x19, [sp, 16]
>>       mov     x19, x1
>>       str     d1, [x0]
>>       bl      lrint
>>       str     x0, [x19]
>>       ldr     x19, [sp, 16]
>>       ldp     x29, x30, [sp], 32
>>       ret
>>
>> Bootstrapped and regtested on aarch64-none-linux-gnu and no regressions.
>> The patch also has no regressions on Spec2006.
>>
>> Ok for trunk?
>
> OK.
>
> Thanks,
> James
>
>>
>> gcc/
>> 2017-06-07  Tamar Christina  <tamar.christina@arm.com>
>>
>>       * config/aarch64/aarch64.md (lrint<GPF:mode><GPI:mode>2): New.
>>
>> gcc/testsuite/
>> 2017-06-07  Tamar Christina  <tamar.christina@arm.com>
>>
>>       * gcc.target/aarch64/lrint-matherr.h: New.
>>       * gcc.target/aarch64/inline-lrint_1.c: New.
>>       * gcc.target/aarch64/inline-lrint_2.c: New.
>>       * gcc.target/aarch64/no-inline-lrint_1.c: New.
>>       * gcc.target/aarch64/no-inline-lrint_2.c: New.
>
>

The tests
    gcc.target/aarch64/inline-lrint_1.c scan-assembler-times
fcvtzs\tx[0-9]+, d[0-9]+ 3
    gcc.target/aarch64/inline-lrint_1.c scan-assembler-times
fcvtzs\tx[0-9]+, s[0-9]+ 3
    gcc.target/aarch64/inline-lrint_1.c scan-assembler-times
frintx\td[0-9]+, d[0-9]+ 3
    gcc.target/aarch64/inline-lrint_1.c scan-assembler-times
frintx\ts[0-9]+, s[0-9]+ 3
    gcc.target/aarch64/no-inline-lrint_1.c scan-assembler-times
frintx\td[0-9]+, d[0-9]+ 3
    gcc.target/aarch64/no-inline-lrint_1.c scan-assembler-times
frintx\ts[0-9]+, s[0-9]+ 3
fail on aarch64 bare-metal targets (and pass on aarch64-linux-gnu)